import base64
import hashlib
from asyncio import sleep
from enum import IntEnum
from sqlite3 import Connection, connect
from time import time as now_timestamp
from typing import Iterable, Optional

from discord import Attachment, Guild, Interaction, Member, Role, TextStyle
from discord.app_commands import Group, command, guild_only, guilds
from discord.errors import HTTPException
from discord.ui import FileUpload, Label, Modal, TextDisplay, TextInput
from discord.utils import escape_markdown

from config import CONFIG
from rocketbot.bot import Rocketbot
from rocketbot.cogs.basecog import BaseCog
from rocketbot.cogsetting import CogSetting
from rocketbot.utils import (
	MOD_PERMISSIONS,
	dump_stacktrace,
	is_discord_username,
	is_email_address,
)

PERMITTED_GUILD_IDS = [
	405011810937339905,
	900805482825007104,  # test server
]
class KickstarterCog(BaseCog):
	"""
	Provides a way for Discord users to self-identify the email address they
	used when backing a relevant Kickstarter campaign. If the email address is
	found in a sqlite database, a configured backer role will be given to the
	user. If the address isn't found, they can either try again or the address
	can be saved and linked up the next time the database is refreshed.

	Discord does not currently have a native Kickstarter integration, and doing
	a full API integration is a bit ambitious, so this is a stopgap solution.
	"""

	shared: Optional['KickstarterCog'] = None

	SETTING_ENABLED = CogSetting(
		name='enabled',
		datatype=bool,
		default_value=False,
		brief='Kickstarter user linking',
		description='Whether this module is enabled for a guild.',
	)
	SETTING_ROLE = CogSetting(
		name='backer_role',
		datatype=int,
		default_value=0,
		brief='role to assign to Kickstarter backers',
		description='Role automatically assigned to members who use /link with '
			'a known Kickstarter email address.'
	)

	def __init__(self, bot: Rocketbot):
		super().__init__(
			bot,
			config_prefix='kickstarter',
			short_description='For linking Kickstarter backers to their Discord handles.',
		)
		Self = KickstarterCog
		self.add_setting(Self.SETTING_ENABLED)
		self.con: Connection = connect('kickstarter.sqlite3')
		Self.shared = self

	async def __fetch_backer_role(self, guild: Guild) -> Role:
		Self = KickstarterCog
		role_id = self.get_guild_setting(guild, Self.SETTING_ROLE)
		if role_id is None or role_id == 0:
			raise _NoBackerRoleException()
		return guild.get_role(role_id) or await guild.fetch_role(role_id)
	
	def __get_cached_backer_role(self, guild: Guild) -> Optional[Role]:
		"""Synchronously gets the configured backer role from the cache if possible."""
		Self = KickstarterCog
		role_id = self.get_guild_setting(guild, Self.SETTING_ROLE)
		if role_id is None or role_id == 0:
			return None
		return guild.get_role(role_id)

	def __set_backer_role(self, role: Role):
		Self = KickstarterCog
		self.set_guild_setting(role.guild, Self.SETTING_ROLE, role.id)

	# -- Member commands -----

	@command(
		description='Links your Kickstarter email address to your Discord user'
	)
	@guild_only()
	@guilds(PERMITTED_GUILD_IDS)
	async def link_email(self, interaction: Interaction):
		# If possible, try to check if they're already a backer before opening
		# a modal.
		guild = interaction.guild
		if not self.get_guild_setting(guild, KickstarterCog.SETTING_ENABLED):
			return
		backer_role = self.__get_cached_backer_role(guild)
		member: Member = interaction.user
		if backer_role is not None and backer_role in member.roles:
			text = f"{CONFIG['info_emoji']} You have already been given the " \
				"backer role and should have access to backer-only areas.\n" \
				"\n" \
				"Please message a moderator if you're having trouble."
			await interaction.response.send_message(text, ephemeral=True)
			return

		await interaction.response.send_modal(_LinkModal())

	@command(
		description='Grants you access to Kickstarter backer-only areas'
	)
	@guild_only()
	@guilds(PERMITTED_GUILD_IDS)
	async def link_username(self, interaction: Interaction):
		await interaction.response.defer(ephemeral=True, thinking=True)
		try:
			backer_role = await self.__fetch_backer_role(interaction.guild)
		except _NoBackerRoleException:
			text = f"{CONFIG['failure_emoji']} Oops! The server admin hasn't " \
				"setup this feature just yet. Check back later."
			await interaction.followup.send(text, ephemeral=True)
			return

		member: Member = interaction.user
		if backer_role is not None and backer_role in member.roles:
			text = f"{CONFIG['info_emoji']} You have already been given the " \
				"backer role and should have access to backer-only areas.\n" \
				"\n" \
				"Please message a moderator if you're having trouble."
			await interaction.followup.send(text, ephemeral=True)
			return

		ks_username = self.__fetch_kickstarter_username(username=interaction.user.name)
		if ks_username is None:
			text = f"{CONFIG['warning_emoji']} We don't have your Discord " \
				f"username `{member.name}` in our list of backers. Did you " \
				"spell it correctly in the form? Contact a moderator if you " \
				"think there was a mistake."
			await interaction.followup.send(text, ephemeral=True)
			return

		ks_username.discord_member_id = member.id
		ks_username.lookup_status = _LookupStatus.member_found
		self.__update_kickstarter_username(ks_username)
		await member.add_roles(backer_role)
		text = f"{CONFIG['success_emoji']} Success! You should now have access to " \
			"backer-only areas! Thanks for your support!"
		await interaction.followup.send(text, ephemeral=True)

	@command(
		description='Unlinks your Kickstarter email address from your Discord ' \
			'user and removes the backer role.'
	)
	@guild_only()
	@guilds(PERMITTED_GUILD_IDS)
	async def unlink(self, interaction: Interaction):
		await interaction.response.defer(ephemeral=True, thinking=True)
		guild = interaction.guild
		member = interaction.user

		try:
			backer_role: Role = await self.__fetch_backer_role(guild)
		except _NoBackerRoleException:
			text = f"{CONFIG['failure_emoji']} Oops! The server admin hasn't " \
				"setup this feature just yet. Check back later."
			await interaction.followup.send(text, ephemeral=True)
			return
		if backer_role in member.roles:
			await member.remove_roles(backer_role)
		self.__delete_member_link(guild.id, member.id)
		text = f"{CONFIG['success_emoji']} Unlinked as Kickstarter backer. Use " \
			"`/link` if you change your mind."
		await interaction.followup.send(text, ephemeral=True)

	# -- Admin commands -----

	kickstarter = Group(
		name='kickstarter',
		description='Manages roles for users identified as Kickstarter backers.',
		guild_only=True,
		guild_ids=PERMITTED_GUILD_IDS,
		default_permissions=MOD_PERMISSIONS
	)

	@kickstarter.command(
		description='Configures which role to give to Kickstarter backers.'
	)
	async def set_role(self, interaction: Interaction, role: Role):
		self.__set_backer_role(role)
		text = f"{CONFIG['info_emoji']} Backer role set to {role.name}"
		await interaction.response.send_message(text, ephemeral=True)

	@kickstarter.command(
		description='Checks the database for users to assign the backer role to.'
	)
	async def sync_emails(self, interaction: Interaction):
		await interaction.response.defer(ephemeral=True, thinking=True)
		sync_result: _SyncEmailsResult = await self.__sync_by_email(interaction.guild)
		text = f"{CONFIG['success_emoji']} Sync complete.\n" + \
			sync_result.summary_markdown()
		await interaction.followup.send(text, ephemeral=True)

	@kickstarter.command(
		description='Checks the database for users to assign the backer role to.'
	)
	async def sync_usernames(self, interaction: Interaction):
		await interaction.response.defer(ephemeral=True, thinking=True)
		sync_result: _SyncUsernamesResult = await self.__sync_by_username(interaction.guild)
		text = f"{CONFIG['success_emoji']} Sync complete.\n" + \
			sync_result.summary_markdown()
		await interaction.followup.send(text, ephemeral=True)

	@kickstarter.command(
		description='DEV TEST - testing timeout'
	)
	async def timeout_test(self, interaction: Interaction):
		await interaction.response.defer(ephemeral=True, thinking=True)
		await sleep(300)
		await interaction.followup.send("5m timer done", ephemeral=True)

	@kickstarter.command(
		description='Shows info about Kickstarter linked Discord members.'
	)
	async def info(self, interaction: Interaction):
		await interaction.response.defer(ephemeral=True, thinking=True)
		guild = interaction.guild
		backer_role = await self.__fetch_backer_role(guild)
		stats: _Stats = self.__fetch_stats(guild.id)

		lines: list[str] = []
		if backer_role is None:
			lines.append("- No backer role configured yet (use `/kickstarter set_role`)")
		else:
			lines.append(f"- Backer role configured as `{backer_role.name}`")
		if stats.email_count > 0:
			lines.append(f"- **{stats.email_count}** email addresses imported")
			lines.append(f"- New emails last imported at <t:{stats.email_last_imported_at}:f>")
		if stats.complete_link_count + stats.incomplete_link_count > 0:
			lines.append(f"- **{stats.complete_link_count}** members linked by email")
			lines.append(f"- **{stats.incomplete_link_count}** members provided emails but weren't linked yet")
		if stats.username_count > 0:
			lines.append(f"- **{stats.username_count}** Discord usernames imported")
			lines.append(f"- New usernames last imported at <t:{stats.username_last_imported_at}:f>")
			lines.append(f"- **{stats.username_found_count}** usernames linked successfully")
			lines.append(f"- **{stats.username_not_found_count}** usernames not (yet) linked to members")
			lines.append(f"- **{stats.username_unprocessed_count}** usernames not yet attempted to sync")

		text = f"{CONFIG['info_emoji']} Kickstarter import stats\n"
		text += "\n".join(lines)
		await interaction.followup.send(text, ephemeral=True)

	@kickstarter.command(
		description='Shows Kickstarter link details about a specific Discord member.'
	)
	async def find_member(self, interaction: Interaction, member: Member):
		await interaction.response.defer(ephemeral=True, thinking=True)
		guild = interaction.guild
		try:
			backer_role = await self.__fetch_backer_role(guild)
		except _NoBackerRoleException:
			text = f"{CONFIG['failure_emoji']} Backer role not yet configured!"
			await interaction.followup.send(text, ephemeral=True)
			return

		if backer_role in member.roles:
			text = f"{CONFIG['info_emoji']} Member {member.name} has `{backer_role.name}` role."
			await interaction.followup.send(text, ephemeral=True)
			return

		username_record = self.__fetch_kickstarter_username(username=member.name)
		if username_record is not None:
			await member.add_roles(backer_role)
			username_record.lookup_status = _LookupStatus.member_found
			self.__update_kickstarter_username(username_record)
			text = f"{CONFIG['success_emoji']} Member's username found in Kickstarter export. Assigned `{backer_role.name}` role."
			await interaction.followup.send(text, ephemeral=True)
			return

		# FIXME: Sorta splitting the difference between email and username model here

		member_link = self.__fetch_member_link_by_member_id(guild.id, member.id)
		if member_link is None:
			text = f"No record found for member {member.mention}. Possible reasons:\n" \
				"- They haven't used the `/link` command yet to provide their " \
				"Kickstarter email address\n" \
				"- They linked using a different Discord account. (You can " \
				"search by email with `/find_email`)\n" \
				"- They used the `/unlink` after being linked"
			await interaction.followup.send(text, ephemeral=True)
			return

		text = f"Member {member.mention} successfully used the `/link` command"
		if backer_role in member.roles:
			text += f", and they already have the {backer_role.name} Discord role. " \
				"They should already have access to backer-only areas. If they " \
				"still can't see them, some possible reasons:\n" \
				"- Its channel group is collapsed in the channel list.\n" \
				"- Some channels are hidden. Direct them to the Browse Channels " \
				"area in the channel list to see if it's listed and checked visible.\n" \
				"- Their client may need to be refreshed. Have them restart Discord " \
				"and see if the channel shows up."
		else:
			is_backer = self.__is_kickstarter_email_hash(interaction.guild.id, member_link.email_hash)
			if is_backer:
				await member.add_roles(backer_role)
				text += f", and their email address is in the Kickstarter backer list, " \
					f"but they didn't have the {backer_role.name} role yet! **This was " \
					"just now corrected.** Ask them to check again."
			else:
				text += ", but we don't have the address they provided in the " \
					"Kickstarter backer list yet. Have we refreshed it recently?"
		await interaction.followup.send(text, ephemeral=True)

	@kickstarter.command(
		description='Shows Kickstarter link details for a given email address.'
	)
	async def find_email(self, interaction: Interaction, email: str):
		await interaction.response.defer(ephemeral=True, thinking=True)
		guild = interaction.guild
		try:
			backer_role = await self.__fetch_backer_role(guild)
		except _NoBackerRoleException:
			text = f"{CONFIG['failure_emoji']} Backer role not yet configured!"
			await interaction.followup.send(text, ephemeral=True)
			return

		member_link = self.__fetch_member_link_by_email(guild.id, email)
		is_backer = self.__is_kickstarter_email(guild.id, email)
		member = guild.get_member(member_link.member_id) or \
			await guild.fetch_member(member_link.member_id) \
			if member_link is not None else None
		has_role = member is not None and backer_role in member.roles

		lines: list[str] = []
		if not is_email_address(email):
			lines.append("- Email address doesn't look valid but searching anyway.")
		if member_link is not None:
			if member is not None:
				lines.append(f"- Server member {member.mention} (username " \
					f"{member.username}, id {member.id}) used `/link` with " \
					"this address.")
				if has_role:
					lines.append(f"- Member has the {backer_role.name} role.")
				else:
					lines.append(f"- Member does not have the {backer_role.name} role.")
			else:
				lines.append(f"- User <@{member_link.member_id}> (id {member.id}) " \
					"used `/link` but they couldn't be retrieved, perhaps because " \
					"they left the server.")
		else:
			lines.append("- No one has used `/link` with that address yet.")

		if is_backer:
			lines.append("- Email address is in latest Kickstarter backer export.")
		else:
			lines.append("- Email address is not found in the latest Kickstarter " \
				"backer export.")

		if member is not None and is_backer and not has_role:
			# Member doesn't have role but should
			await member.add_roles(backer_role)
			if member_link is not None:
				member_link.complete = True
				self.__update_member_link(member_link)
			else:
				member_link = _MemberLink(0, guild.id, member.id,
					KickstarterCog.__hash_email_address(email), True)
				self.__create_member_link(member_link)
			lines.append("- **Fixed:** Member is a backer and has been given " \
				f"{backer_role.name} role.")

		text = f"{CONFIG['info_emoji']} Email search for `{escape_markdown(email)}`\n" + \
			("\n".join(lines))
		await interaction.followup.send(text, ephemeral=True)

	@kickstarter.command(
		description='Uploads an export of Kickstarter backer email addresses.'
	)
	async def upload_emails(self, interaction: Interaction):
		await interaction.response.send_modal(_UploadEmailsModal())

	@kickstarter.command(
		description='Uploads an export of backer Discord usernames.'
	)
	async def upload_usernames(self, interaction: Interaction):
		await interaction.response.send_modal(_UploadUsernamesModal())

	async def interaction_check(self, interaction: Interaction) -> bool:
		if interaction.command is not None:
			self.__trace(interaction.guild, f"@{interaction.user.name} used /{interaction.command.qualified_name}")
		return True

	async def on_email_upload_submit(self, interaction: Interaction, attachment: Attachment):
		"""Callback for email upload modal."""
		await interaction.response.defer(ephemeral=True, thinking=True)
		guild = interaction.guild
		import_result: _ImportResult = await self.__import_emails(guild, attachment)
		try:
			sync_result: _SyncEmailsResult = await self.__sync_by_email(guild)
			text = f"{CONFIG['success_emoji']} Email import complete.\n" + \
				import_result.summary_markdown() + "\n" + \
				sync_result.summary_markdown()
		except _NoBackerRoleException:
			text = f"{CONFIG['failure_emoji']} Backer role must be configured " \
				"before importing."
		await interaction.followup.send(text, ephemeral=True)

	async def on_username_upload_submit(self, interaction: Interaction, attachment: Attachment):
		"""Callback for username upload modal."""
		await interaction.response.defer(ephemeral=True, thinking=True)
		guild = interaction.guild
		import_result: _ImportResult = await self.__import_usernames(guild, attachment)
		try:
			sync_result: _SyncUsernamesResult = await self.__sync_by_username(guild)
			text = f"{CONFIG['success_emoji']} Username import complete.\n" + \
				import_result.summary_markdown() + "\n" + \
				sync_result.summary_markdown()
		except _NoBackerRoleException:
			text = f"{CONFIG['failure_emoji']} Backer role must be configured " \
				"before importing."
		await interaction.followup.send(text, ephemeral=True)

	async def on_link_email_submit(self, interaction: Interaction, email: str):
		"""Callback for link modal."""
		await interaction.response.defer(ephemeral=True, thinking=True)
		try:
			result: _LinkResult = await self.__link_member(interaction.guild,
				interaction.user, email)
		except _NoBackerRoleException:
			text = f"{CONFIG['failure_emoji']} Oops! The server admin hasn't setup " \
				"this feature just yet. Check back later."
			await interaction.followup.send(text, ephemeral=True)
			return

		if result.status == _LinkResultStatus.malformed_address:
			text = f"{CONFIG['failure_emoji']} That email address doesn't look " \
				"like the right format.\n" \
				f"```\n{escape_markdown(email)}\n```\n" \
				"It should look something like:\n" \
				"```\nyourname@server.com\n```\n" \
				"If you need help, please contact a moderator."
		elif result.status == _LinkResultStatus.already_have_role:
			text = f"{CONFIG['info_emoji']} You already have the backer role " \
				"and should have access to backer-only areas. If you're still " \
				"having problems or have questions, please contact a moderator."
		elif result.status == _LinkResultStatus.linked_to_other_account:
			text = f"{CONFIG['failure_emoji']} That email address is already " \
				"linked to a different Discord member. Did you link with " \
				"an alternate Discord account? Contact a mod if you need help."
		elif result.status in (
			_LinkResultStatus.link_pending_new,
			_LinkResultStatus.link_pending_dupe,
			_LinkResultStatus.link_pending_updated
		):
			if result.status == _LinkResultStatus.link_pending_new:
				text = f"{CONFIG['info_emoji']} Email address linked!\n\n"
			else:
				text = f"{CONFIG['info_emoji']} Email address updated!\n\n"
			text += "We just need to confirm the address is on the backer list, " \
				"and then you'll be given access to the backers-only areas of " \
				"the server. In the meantime, double check that the email you " \
				"gave us is the same one you used to back the project on " \
				"Kickstarter:\n" \
				"\n" \
				f"> `{escape_markdown(email)}`\n" \
				"\n" \
				"If you need to make a correction, just use `/link` again to update it."
		elif result.status == _LinkResultStatus.link_success:
			text = f"{CONFIG['success_emoji']} Success! You should now have access to " \
				"backer-only areas! Thanks for your support!"

		await interaction.followup.send(text, ephemeral=True)

	async def __link_member(self, guild: Guild, member: Member, email: str) -> '_LinkResult':
		if not is_email_address(email.strip()):
			return _LinkResult(_LinkResultStatus.malformed_address)

		input_email_hash = KickstarterCog.__hash_email_address(email)
		backer_role: Role = await self.__fetch_backer_role(guild)

		if backer_role in member.roles:
			return _LinkResult(_LinkResultStatus.already_have_role)

		existing_email_link = self.__fetch_member_link_by_email(guild.id, email)
		if existing_email_link is not None and existing_email_link.member_id != member.id:
			return _LinkResult(_LinkResultStatus.linked_to_other_account)

		member_link = self.__fetch_member_link_by_member_id(guild.id, member.id)
		if self.__is_kickstarter_email(guild.id, email):
			await member.add_roles(backer_role)
			if member_link is not None:
				member_link.email_hash = input_email_hash
				member_link.complete = True
				self.__update_member_link(member_link)
			else:
				member_link = _MemberLink(0, guild.id, member.id, input_email_hash, True)
				self.__create_member_link(member_link)
			return _LinkResult(_LinkResultStatus.link_success)

		if member_link is not None:
			if member_link.email_hash == input_email_hash:
				return _LinkResult(_LinkResultStatus.link_pending_dupe)
			member_link.email_hash = input_email_hash
			self.__update_member_link(member_link)
			return _LinkResult(_LinkResultStatus.link_pending_updated)

		member_link = _MemberLink(0, guild.id, member.id, input_email_hash, False)
		self.__create_member_link(member_link)
		return _LinkResult(_LinkResultStatus.link_pending_new)

	async def __import_emails(self, guild: Guild, attachment: Attachment) -> '_ImportResult':
		"""Imports email addresses from an upload attachment."""
		self.__trace(guild, f"Download - start - {attachment.filename} " \
			f"({attachment.size} bytes, {attachment.content_type})")
		file_bytes = await attachment.read()
		file_str = file_bytes.decode('utf-8')
		self.__trace(guild, "Download - complete")

		self.__trace(guild, "Parse - start")
		lines = file_str.splitlines(keepends=False)
		addresses = []
		malformed_count = 0
		for line in lines:
			line = line.strip()
			if (line.startswith('"') and line.endswith('"')) or \
				(line.startswith("'") and line.endswith("'")):
				# Remove quotes
				line = line[1:-1].strip()
			if line == '':
				continue
			if is_email_address(line):
				addresses.append(line)
			else:
				self.__trace(guild, f"Malformed email address {line}")
				malformed_count += 1
		self.__trace(guild, f"Parse - complete - {len(lines)} lines, {len(addresses)} " \
			f"valid addresses, {malformed_count} malformed addresses")

		self.__trace(guild, f"Storing - start - {len(addresses)} addresses")
		new_address_count = self.__store_kickstarter_emails(guild.id, addresses)
		self.__trace(guild, f"Storing - complete - {new_address_count} unique " \
			"addresses stored")

		return _ImportResult(
			attachment.filename,
			attachment.size,
			len(lines),
			len(addresses),
			malformed_count,
			new_address_count
		)

	async def __import_usernames(self, guild: Guild, attachment: Attachment) -> '_ImportResult':
		"""Imports Discord usernames from an upload attachment."""
		self.__trace(guild, f"Download - start - {attachment.filename} " \
			f"({attachment.size} bytes, {attachment.content_type})")
		file_bytes = await attachment.read()
		file_str = file_bytes.decode('utf-8')
		self.__trace(guild, "Download - complete")

		self.__trace(guild, "Parse - start")
		lines = file_str.splitlines(keepends=False)
		usernames = []
		malformed_count = 0
		for line in lines:
			line = self.__normalize_discord_username(line)
			if (line.startswith('"') and line.endswith('"')) or \
				(line.startswith("'") and line.endswith("'")):
				# Remove quotes
				line = line[1:-1].strip()
			if line == '':
				continue
			if is_discord_username(line):
				usernames.append(line)
			else:
				self.__trace(guild, f"Malformed Discord username \"{line}\"")
				malformed_count += 1
		self.__trace(guild, f"Parse - complete - {len(lines)} lines, {len(usernames)} " \
			f"valid usernames, {malformed_count} malformed usernames")

		self.__trace(guild, f"Storing - start - {len(usernames)} usernames")
		new_username_count = self.__store_kickstarter_usernames(guild.id, usernames)
		self.__trace(guild, f"Storing - complete - {new_username_count} unique " \
			"usernames stored")

		return _ImportResult(
			attachment.filename,
			attachment.size,
			len(lines),
			len(usernames),
			malformed_count,
			new_username_count
		)

	async def __sync_by_email(self, guild: Guild) -> '_SyncEmailsResult':
		"""Looks for members to assign the backer role from Kickstarter imports."""
		backer_role = await self.__fetch_backer_role(guild)
		incomplete_links: list[_MemberLink] = self.__fetch_incomplete_member_links(guild.id)
		complete_count = 0
		incomplete_count = 0
		member_not_found_count = 0
		async def link_loop_handler(link: _MemberLink):
			nonlocal member_not_found_count
			nonlocal complete_count
			nonlocal incomplete_count
			if not self.__is_kickstarter_email_hash(guild.id, link.email_hash):
				incomplete_count += 1
				return
			member = guild.get_member(link.member_id) or \
				await guild.fetch_member(link.member_id)
			if member is None:
				member_not_found_count += 1
			else:
				if backer_role not in member.roles:
					await member.add_roles(backer_role)
				link.complete = True
				self.__update_member_link(link)
				complete_count += 1
		failure_count = await self.__throttled_loop(guild, incomplete_links, link_loop_handler)
		return _SyncEmailsResult(complete_count, incomplete_count, failure_count, member_not_found_count)

	async def __sync_by_username(self, guild: Guild) -> '_SyncUsernamesResult':
		backer_role = await self.__fetch_backer_role(guild)
		complete_count = 0
		not_found_count = 0
		usernames: list[_KickstarterDiscordUser] = \
			self.__fetch_incomplete_kickstarter_usernames(guild.id,
				_LookupStatus.username_not_found)
		username_to_member_id: dict[str, int] = {}
		if self.bot.intents.members:
			async for member in guild.fetch_members(limit=None):
				username_to_member_id[member.name] = member.id
		async def username_loop_handler(username: _KickstarterDiscordUser):
			nonlocal complete_count
			nonlocal not_found_count
			member_id = username_to_member_id.get(username.discord_username)
			if member_id is not None:
				member = guild.get_member(member_id) or \
					await guild.fetch_member(member_id)
			else:
				member = guild.get_member_named(username.discord_username)
			if member is None:
				not_found_count += 1
				if username.lookup_status != _LookupStatus.username_not_found:
					username.lookup_status = _LookupStatus.username_not_found
					self.__update_kickstarter_username(username)
				return
			username.lookup_status = _LookupStatus.member_found
			username.discord_member_id = member.id
			self.__update_kickstarter_username(username)
			if backer_role not in member.roles:
				await member.add_roles(backer_role)
				complete_count += 1
		failure_count = await self.__throttled_loop(guild, usernames, username_loop_handler)
		return _SyncUsernamesResult(complete_count, not_found_count, failure_count)

	async def __throttled_loop(self, guild: Guild, iter: Iterable, callback) -> int:
		"""Iterates a loop with automatically adjusting sleeps based on
		throttling exceptions."""
		failure_count = 0
		sleep_length = 0.0
		for elem in iter:
			complete = False
			for _ in range(5):
				try:
					await sleep(sleep_length)
					await callback(elem)
					complete = True
					break
				except HTTPException as ex:
					if ex.status == 429:  # rate limited
						retry_header_value = ex.response.headers.get('retry_after')
						retry_after_millis = float(retry_header_value or '1000')
						self.__trace(guild, "Rate limited while processing. " \
							f"retry_after={retry_header_value}")
						await sleep(retry_after_millis / 1000.0)
						sleep_length = 1.0 if sleep_length == 0.0 else sleep_length * 2.0
						self.__trace(guild, f"Sleep increased to {sleep_length}s due to rate limiting")
					else:
						dump_stacktrace(ex)
				except BaseException as ex:
					dump_stacktrace(ex)
			if not complete:
				failure_count += 1
		return failure_count


	# -- Database functions -----

	def __store_kickstarter_email(self, record: '_KickstarterEmail'):
		cur = self.con.cursor()
		cur.execute("""
			INSERT OR IGNORE INTO kickstarter_emails (
				guild_id,
				email_hash,
				imported_at
			) VALUES (
				:guild_id,
				:email_hash,
				:imported_at
			)
			""", {
				'guild_id': record.guild_id,
				'email_hash': record.email_hash,
				'imported_at': record.imported_at
			})
		row_id = cur.lastrowid
		self.con.commit()
		cur.close()
		if row_id is not None and row_id != 0:
			record.pk = row_id

	def __store_kickstarter_emails(self, guild_id: int, email_addresses: list[str]) -> int:
		imported_at: int = int(now_timestamp())
		cur = self.con.cursor()
		for email_address in email_addresses:
			email_hash = KickstarterCog.__hash_email_address(email_address)
			cur.execute("""
				INSERT OR IGNORE INTO kickstarter_emails (
					guild_id,
					email_hash,
					imported_at
				) VALUES (
					:guild_id,
					:email_hash,
					:imported_at
				)
				""", {
					'guild_id': guild_id,
					'email_hash': email_hash,
					'imported_at': imported_at
				})
		cur.execute("""
			SELECT COUNT(1)
			FROM kickstarter_emails
			WHERE imported_at = ?
			""", (imported_at, ))
		imported_count = cur.fetchone()[0]
		self.con.commit()
		cur.close()
		return imported_count

	def __is_kickstarter_email(self, guild_id: int, email_address: str) -> bool:
		return self.__is_kickstarter_email_hash(
			guild_id, KickstarterCog.__hash_email_address(email_address))

	def __is_kickstarter_email_hash(self, guild_id: int, email_hash: str) -> bool:
		cur = self.con.cursor()
		cur.execute("""
			SELECT COUNT(1)
			FROM kickstarter_emails
			WHERE guild_id = :guild_id AND email_hash = :email_hash
			""", {
				'guild_id': guild_id,
				'email_hash': email_hash
			})
		count: int = cur.fetchone()[0]
		cur.close()
		return count > 0

	def __store_kickstarter_username(self, record: '_KickstarterDiscordUser'):
		cur = self.con.cursor()
		cur.execute("""
			INSERT OR IGNORE INTO kickstarter_discord_users (
				guild_id,
				discord_username,
				discord_member_id,
				lookup_status,
				imported_at
			) VALUES (
				:guild_id,
				:discord_username,
				:discord_member_id,
				:lookup_status,
				:imported_at
			)
			""", {
				'guild_id': record.guild_id,
				'discord_username': self.__normalize_discord_username(record.discord_username),
				'discord_member_id': record.discord_member_id,
				'lookup_status': record.lookup_status,
				'imported_at': record.imported_at
			})
		row_id = cur.lastrowid
		self.con.commit()
		cur.close()
		if row_id is not None and row_id != 0:
			record.pk = row_id

	def __store_kickstarter_usernames(self, guild_id: int, usernames: list[str]) -> int:
		imported_at: int = int(now_timestamp())
		cur = self.con.cursor()
		for username in usernames:
			cur.execute("""
				INSERT OR IGNORE INTO kickstarter_discord_users (
					guild_id,
					discord_username,
					imported_at
				) VALUES (
					:guild_id,
					:discord_username,
					:imported_at
				)
				""", {
					'guild_id': guild_id,
					'discord_username': self.__normalize_discord_username(username),
					'imported_at': imported_at
				})
		cur.execute("""
			SELECT COUNT(1)
			FROM kickstarter_discord_users
			WHERE imported_at = ?
			""", (imported_at, ))
		imported_count = cur.fetchone()[0]
		self.con.commit()
		cur.close()
		return imported_count

	def __fetch_kickstarter_username(self, member_id: Optional[int] = None, username: Optional[str] = None) -> Optional['_KickstarterDiscordUser']:
		"""Fetches an imported Discord username by EITHER member id or username
		(must provide exactly one)"""
		cur = self.con.cursor()
		cur.row_factory = lambda c, r: _KickstarterDiscordUser(*r)
		if member_id is not None:
			cur.execute("""
				SELECT *
				FROM kickstarter_discord_users
				WHERE discord_member_id = :member_id
				""", { 'member_id': member_id })
		elif username is not None:
			cur.execute("""
				SELECT *
				FROM kickstarter_discord_users
				WHERE discord_username = :username
				""", { 'username': username })
		ret_val = cur.fetchone()
		cur.close()
		return ret_val

	def __fetch_incomplete_kickstarter_usernames(self, guild_id: int, max_status: '_LookupStatus') -> list['_KickstarterDiscordUser']:
		cur = self.con.cursor()
		cur.row_factory = lambda c, r: _KickstarterDiscordUser(*r)
		cur.execute("""
			SELECT *
			FROM kickstarter_discord_users
			WHERE guild_id = :guild_id AND lookup_status <= :lookup_status
			""", { 'guild_id': guild_id, 'lookup_status': max_status })
		ret_val = cur.fetchall()
		cur.close()
		return ret_val

	def __update_kickstarter_username(self, user: '_KickstarterDiscordUser'):
		cur = self.con.cursor()
		cur.execute("""
			UPDATE kickstarter_discord_users
			SET discord_member_id = :discord_member_id,
				lookup_status = :lookup_status
			WHERE pk = :pk
			""", {
				'discord_member_id': user.discord_member_id,
				'lookup_status': user.lookup_status,
				'pk': user.pk
			})
		self.con.commit()
		cur.close()

	def __create_member_link(self, record: '_MemberLink'):
		cur = self.con.cursor()
		cur.execute("""
			INSERT OR IGNORE INTO member_links (
				guild_id,
				member_id,
				email_hash,
				complete
			) VALUES (
				:guild_id,
				:member_id,
				:email_hash,
				:complete
			)
			""", {
				'guild_id': record.guild_id,
				'member_id': record.member_id,
				'email_hash': record.email_hash,
				'complete': record.complete
			})
		row_id = cur.lastrowid
		if row_id is not None and row_id != 0:
			record.pk = row_id
		self.con.commit()
		cur.close()

	def __fetch_member_link_by_member_id(self, guild_id: int, member_id: int) -> Optional['_MemberLink']:
		cur = self.con.cursor()
		cur.row_factory = lambda c, r: _MemberLink(*r)
		cur.execute("""
			SELECT *
			FROM member_links
			WHERE guild_id = :guild_id AND member_id = :member_id
			""", (guild_id, member_id, ))
		ret_val = cur.fetchone()
		cur.close()
		return ret_val

	def __fetch_member_link_by_email(self, guild_id: int, email_address: str) -> Optional['_MemberLink']:
		cur = self.con.cursor()
		cur.row_factory = lambda c, r: _MemberLink(*r)
		email_hash = KickstarterCog.__hash_email_address(email_address)
		cur.execute("""
			SELECT *
			FROM member_links
			WHERE guild_id = :guild_id AND email_hash = :email_hash
			""", {
				'guild_id': guild_id,
				'email_hash': email_hash
			})
		ret_val = cur.fetchone()
		cur.close()
		return ret_val

	def __delete_member_link(self, guild_id: int, member_id: int):
		cur = self.con.cursor()
		cur.execute("""
			DELETE FROM member_links
			WHERE guild_id = :guild_id AND member_id = :member_id
		""", { 'guild_id': guild_id, 'member_id': member_id })
		cur.close()

	def __update_member_link(self, member_link: '_MemberLink'):
		cur = self.con.cursor()
		cur.execute("""
			UPDATE member_links
			SET
				email_hash = :email_hash,
				complete = :complete
			WHERE guild_id = :guild_id AND member_id = :member_id
		""", {
			'email_hash': member_link.email_hash,
			'complete': 1 if member_link.complete else 0,
			'guild_id': member_link.guild_id,
			'member_id': member_link.member_id
		})
		self.con.commit()
		cur.close()

	def __fetch_incomplete_member_links(self, guild_id: int) -> list['_MemberLink']:
		cur = self.con.cursor()
		cur.row_factory = lambda c, r: _MemberLink(*r)
		cur.execute("""
			SELECT *
			FROM member_links
			WHERE guild_id = ? AND complete = 0
			""", (guild_id, ))
		ret_val = cur.fetchall()
		cur.close()
		return ret_val

	def __fetch_stats(self, guild_id: int) -> '_Stats':
		"""Returns a tuple with the number of completed links, incomplete links,
		and imported Kickstarter emails."""
		cur = self.con.cursor()

		cur.execute("""
			SELECT
				(
					SELECT COUNT(1)
					FROM member_links
					WHERE complete = 1 AND guild_id = :guild_id
				) AS complete,
				(
					SELECT COUNT(1)
					FROM member_links
					WHERE complete = 0 AND guild_id = :guild_id
				) AS incomplete
			""", { 'guild_id': guild_id })
		(
			complete_link_count,
			incomplete_link_count
		) = cur.fetchone()

		cur.execute("""
			SELECT
				COUNT(1),
				MAX(imported_at)
			FROM kickstarter_emails
			""")
		(
			email_count,
			email_last_imported_at
		) = cur.fetchone()

		cur.execute("""
			SELECT
				COUNT(1) AS total,
				SUM(IIF(lookup_status = 0, 1, 0)) AS unprocessed_count,
				SUM(IIF(lookup_status = 1, 1, 0)) AS not_found_count,
				SUM(IIF(lookup_status = 2, 1, 0)) AS found_count,
				MAX(imported_at) AS last_import
			FROM kickstarter_discord_users
			""")
		(
			username_count,
			username_unprocessed_count,
			username_not_found_count,
			username_found_count,
			username_last_imported_at
		) = cur.fetchone()

		cur.close()
		return _Stats(
			complete_link_count,
			incomplete_link_count,
			email_count,
			email_last_imported_at,
			username_count,
			username_unprocessed_count,
			username_not_found_count,
			username_found_count,
			username_last_imported_at
		)

	# -- Utils -----

	def __trace(self, guild: Guild, message: str):
		self.log(guild, message)

	@staticmethod
	def __normalize_email_address(email_address: str) -> str:
		"""Normalizes an email address for consistent equivalence tests."""
		return email_address.strip().lower()

	@staticmethod
	def __hash_email_address(email_address: str) -> str:
		"""Returns a hash string of the given email address. The address is first
		normalized as lowercase and trimmed of whitespace before hashing."""
		m = hashlib.sha256()
		to_hash = KickstarterCog.__normalize_email_address(email_address)
		m.update(to_hash.encode('utf-8'))
		digest_bytes = m.digest()
		return base64.urlsafe_b64encode(digest_bytes).decode('utf-8')

	@staticmethod
	def __normalize_discord_username(username: str) -> str:
		norm = username.lower().strip()
		if norm.startswith('@'):
			norm = norm[1:]
		return norm

class _KickstarterEmail:
	"""kickstarter_email table row"""
	def __init__(self,
		pk: int,
		guild_id: int,
		email_hash: str,
		imported_at: int
	):
		self.pk: str = pk
		self.guild_id: int = guild_id
		self.email_hash: str = email_hash
		self.imported_at: int = imported_at

class _LookupStatus(IntEnum):
	# Username imported but has not been looked up yet
	unprocessed = 0
	# Username was searched for in guild but not found (user might not have joined yet)
	username_not_found = 1
	# Username found in guild and member id stored
	member_found = 2

class _KickstarterDiscordUser:
	"""kickstarter_discord_users table row"""
	def __init__(self,
		pk: int,
		guild_id: int,
		discord_username: str,
		discord_member_id: Optional[int],
		lookup_status: _LookupStatus,
		imported_at: int
	):
		self.pk: int = pk
		self.guild_id: int = guild_id
		self.discord_username: str = discord_username
		self.discord_member_id: Optional[int] = discord_member_id
		self.lookup_status: _LookupStatus = lookup_status
		self.imported_at: int = imported_at

class _MemberLink:
	"""member_link table row"""
	def __init__(self,
		pk: int,
		guild_id: int,
		member_id: int,
		email_hash: str,
		complete: bool = False
	):
		self.pk: int = pk
		self.guild_id: int = guild_id
		self.member_id: int = member_id
		self.email_hash: str = email_hash
		self.complete: bool = complete

class _Stats:
	def __init__(self,
		complete_link_count: int,
		incomplete_link_count: int,
		email_count: int,
		email_last_imported_at: int,
		username_count: int,
		username_unprocessed_count: int,
		username_not_found_count: int,
		username_found_count: int,
		username_last_imported_at: int
	):
		self.complete_link_count: int = complete_link_count
		self.incomplete_link_count: int = incomplete_link_count
		self.email_count: int = email_count
		self.email_last_imported_at: int = email_last_imported_at
		self.username_count: int = username_count
		self.username_unprocessed_count: int = username_unprocessed_count
		self.username_not_found_count: int = username_not_found_count
		self.username_found_count: int = username_found_count
		self.username_last_imported_at: int = username_last_imported_at

class _NoBackerRoleException(BaseException):
	pass

class _LinkResultStatus(IntEnum):
	# Email address is invalid
	malformed_address = 1
	# User already has backer role, doesn't need to link again
	already_have_role = 2
	# Email address associated with a different Discord account
	linked_to_other_account = 3
	# Can't link right now but email linked to Discord account
	link_pending_new = 4
	# Linked same email address to same Discord account (no action taken)
	link_pending_dupe = 5
	# Replaced email address linked to this Discord account
	link_pending_updated = 6
	# Link successful and backer role given
	link_success = 99

class _LinkResult():
	def __init__(self,
		status: _LinkResultStatus
	):
		self.status: _LinkResultStatus = status

class _ImportResult():
	def __init__(self,
		filename: str,
		file_bytes: int,
		line_count: int,
		valid_record_count: int,
		malformed_record_count: int,
		new_record_count: int
	):
		self.filename: str = filename
		self.file_bytes: int = file_bytes
		self.line_count: int = line_count
		self.valid_record_count: int = valid_record_count
		self.malformed_record_count: int = malformed_record_count
		self.new_record_count: int = new_record_count

	def summary_markdown(self) -> str:
		lines: list[str] = []
		if self.valid_record_count > 0:
			lines.append(f"- Read {self.valid_record_count} valid records")
		else:
			lines.append("- Upload contained **no valid records**")
		if self.malformed_record_count > 0:
			lines.append(f"- Read **{self.malformed_record_count} malformed records**")
		if self.new_record_count > 0:
			lines.append(f"- Imported {self.new_record_count} new unique records")
		else:
			lines.append("- No new unique records (all previously imported)")
		return "\n".join(lines)

class _SyncEmailsResult():
	def __init__(self,
		complete_count: int,
		incomplete_count: int,
		failure_count: int,
		member_not_found_count: int
	):
		self.complete_count: int = complete_count
		self.incomplete_count: int = incomplete_count
		self.failure_count: int = failure_count
		self.member_not_found_count: int = member_not_found_count

	def summary_markdown(self) -> str:
		lines: list[str] = []
		if self.complete_count > 0:
			lines.append(f"- Gave backer role to {self.complete_count} new members")
		else:
			lines.append("- No new members found")
		if self.incomplete_count > 0:
			lines.append(f"- {self.incomplete_count} members provided an email "
				"address to the bot but haven't been found in the Kickstarter "
				"imports yet")
		if self.member_not_found_count > 0:
			lines.append(f"- {self.member_not_found_count} users provided an email "
				"address but couldn't be found (likely left the server). They'll "
				"be handled on next sync if they return.")
		if self.failure_count > 0:
			lines.append(f"- Failed to link {self.failure_count} members")
		return "\n".join(lines)

class _SyncUsernamesResult():
	def __init__(self,
		complete_count: int,
		not_found_count: int,
		failure_count: int
	):
		self.complete_count: int = complete_count
		self.not_found_count: int = not_found_count
		self.failure_count: int = failure_count


	def summary_markdown(self) -> str:
		lines: list[str] = []
		if self.complete_count > 0:
			lines.append(f"- Gave backer role to {self.complete_count} new members")
		else:
			lines.append("- No new members found")
		if self.not_found_count > 0:
			lines.append(f"- {self.not_found_count} members could not be found " \
				"by the provided username")
		if self.failure_count > 0:
			lines.append(f"- Failed to link {self.failure_count} members")
		return "\n".join(lines)

class _LinkModal(Modal):
	text_display = TextDisplay(
		"Gain access to backer-only areas of the server by linking your " \
		"Kickstarter email address.\n" \
		"-# This is only used to verify you are on the backer list. We won't " \
		"email you or ask for your Kickstarter password!"
	)
	email_label = Label(
		text='Kickstarter email',
		# description='Enter the email address associated with your Kickstarter account.',
		component=TextInput(
			style=TextStyle.short,
			placeholder='name@example.com',
			min_length=6,
			max_length=100
		)
	)

	def __init__(self):
		super().__init__(title='Link Kickstarter Address', timeout=None)

	async def on_submit(self, interaction: Interaction) -> None:
		# noinspection PyTypeChecker
		email_input: TextInput = self.email_label.component
		await KickstarterCog.shared.on_link_email_submit(interaction, email_input.value)

	async def on_error(self, interaction: Interaction, error: Exception) -> None:
		dump_stacktrace(error)
		try:
			await interaction.response.send_message(
				f'{CONFIG["failure_emoji"]} Something went wrong. Try using `/link` again.',
				ephemeral=True,
			)
		except BaseException:
			pass

class _UploadEmailsModal(Modal):
	upload_label = Label(
		text='Kickstarter backer email export',
		description='Upload a plain text file containing one backer email address per line.',
		component=FileUpload(
			required=True,
			min_values=1, max_values=1
		)
	)

	def __init__(self):
		super().__init__(title='Upload Emails', timeout=None)

	async def on_submit(self, interaction: Interaction) -> None:
		# noinspection PyTypeChecker
		upload_input: FileUpload = self.upload_label.component
		if len(upload_input.values) < 1:
			text = f"{CONFIG['failure_emoji']} No export file included"
			await interaction.response.send(text, ephemeral=True)
			return
		attachment = upload_input.values[0]
		await KickstarterCog.shared.on_email_upload_submit(interaction, attachment)

	async def on_error(self, interaction: Interaction, error: Exception) -> None:
		dump_stacktrace(error)
		try:
			await interaction.response.send_message(
				f'{CONFIG["failure_emoji"]} Upload failed :(',
				ephemeral=True,
			)
		except BaseException:
			pass

class _UploadUsernamesModal(Modal):
	upload_label = Label(
		text='Discord user export',
		description='Upload a plain text file containing one backer Discord username per line.',
		component=FileUpload(
			required=True,
			min_values=1, max_values=1
		)
	)

	def __init__(self):
		super().__init__(title='Upload Discord Usernames', timeout=None)

	async def on_submit(self, interaction: Interaction) -> None:
		# noinspection PyTypeChecker
		upload_input: FileUpload = self.upload_label.component
		if len(upload_input.values) < 1:
			text = f"{CONFIG['failure_emoji']} No export file included"
			await interaction.response.send(text, ephemeral=True)
			return
		attachment = upload_input.values[0]
		await KickstarterCog.shared.on_username_upload_submit(interaction, attachment)

	async def on_error(self, interaction: Interaction, error: Exception) -> None:
		dump_stacktrace(error)
		try:
			await interaction.response.send_message(
				f'{CONFIG["failure_emoji"]} Upload failed :(',
				ephemeral=True,
			)
		except BaseException:
			pass