import { kody, packageStorage } from 'kody:runtime'
import {
	buildEmailPrompt,
	type GmailMatch,
	type StoredAttachment,
	type StoredEmail,
} from './email-briefing.ts'
import recentThread from './thread.ts'
import {
	aliasCandidates,
	isKentFrom,
	kentOnThisMessage,
	plusAliasesFromMessage,
	consumeNonKentThreadThrottle,
	threadOpenKey,
	threadRateKey,
	type PlusAliasHit,
} from './plus-alias.ts'
import {
	getSecretUseStatus,
	resolveBot,
} from './registry.ts'
import wake, { isWakeTimedOut } from './wake.ts'
import { plainClone, storageGet } from './plain.ts'

export type HandleEmailMessageReceivedInput = {
	event?: string
	message?: Record<string, unknown>
	attachments?: unknown
	dryRun?: boolean
	synthetic?: boolean
	[key: string]: unknown
}

const TEXT_ATTACHMENT_TYPES = [
	'text/',
	'message/rfc822',
	'message/rfc2822',
	'application/json',
	'application/xml',
	'text/calendar',
]
const MAX_TEXT_ATTACHMENT_BYTES = 80_000

function pickDryRun(...values: unknown[]): boolean {
	return values.some((value) => value === true)
}

function asRecord(value: unknown): Record<string, unknown> | null {
	return value && typeof value === 'object' ? (value as Record<string, unknown>) : null
}

function unwrapEvent(input: HandleEmailMessageReceivedInput): {
	message: Record<string, unknown>
	attachments: unknown[]
} {
	const nested = asRecord(input.message)
	if (nested) {
		return {
			message: nested,
			attachments: Array.isArray(input.attachments) ? input.attachments : [],
		}
	}
	const payload = asRecord(input.payload)
	if (payload?.message && typeof payload.message === 'object') {
		return {
			message: payload.message as Record<string, unknown>,
			attachments: Array.isArray(payload.attachments) ? payload.attachments : [],
		}
	}
	return { message: input as Record<string, unknown>, attachments: [] }
}


function decodeBase64(data: string): string {
	try {
		const normalized = data.replace(/-/g, '+').replace(/_/g, '/')
		const pad = normalized.length % 4 === 0 ? '' : '='.repeat(4 - (normalized.length % 4))
		return atob(normalized + pad)
	} catch {
		return ''
	}
}


function isTextAttachment(contentType: string | null | undefined, size: number | null | undefined): boolean {
	if (typeof size === 'number' && size > MAX_TEXT_ATTACHMENT_BYTES) return false
	const type = (contentType || '').toLowerCase()
	return TEXT_ATTACHMENT_TYPES.some((prefix) => type === prefix || type.startsWith(prefix))
}

async function loadAttachmentText(attachment: StoredAttachment): Promise<string | null> {
	if (!attachment.id) return null
	if (!isTextAttachment(attachment.content_type, attachment.size ?? null)) return null
	try {
		const got = await kody.emailAttachmentGet({ attachment_id: attachment.id })
		const b64 = typeof got?.data_base64 === 'string' ? got.data_base64 : ''
		if (!b64) return null
		const text = decodeBase64(b64)
		return text.trim() ? text : null
	} catch {
		return null
	}
}

async function loadFullMessage(messageId: string): Promise<StoredEmail | null> {
	try {
		const full = await kody.emailMessageGet({ message_id: messageId })
		return plainClone(full) as StoredEmail
	} catch {
		return null
	}
}


async function lookupGmail(_message: StoredEmail): Promise<GmailMatch | null> {
	// Intentionally skipped in-subscription: cross-package google stubs were
	// implicated in Workers Proxy serialization failures on this surface.
	return null
}

/**
 * Production `email.message.received` subscriber for Grok Bot plus aliases.
 *
 * Mail to `kentcdodds+patch@inbox.kody.codes` (and the same plus tag on
 * inbox.heykody.app / inbox.heykody.dev) wakes that bot with the full thread
 * briefing. Cold mail from strangers is ignored. Kent including the bot
 * (From Kent, Kent on To/Cc, or a later reply on that opened thread) wakes
 * it. Unaliased mail returns `{ handled: false }` so the Discord inbox
 * subscriber still runs. A late webhook ACK is recorded as handled
 * `wake-timed-out` instead of throwing.
 *
 * @param params.message - Email receipt metadata from the subscription event
 * @param params.dryRun - Inspect routing without waking
 * @returns Handler result with handled flag and bot/alias metadata
 * @example
 * import handleEmailMessageReceived from 'kody:@kentcdodds/grok-bot/handle-email-message-received'
 * const result = await handleEmailMessageReceived({
 *   dryRun: true,
 *   message: {
 *     id: 'msg-1',
 *     from_address: 'kentcdodds@gmail.com',
 *     to_addresses: ['kentcdodds+patch@inbox.kody.codes'],
 *     subject: 'Fwd: Please look at this',
 *   },
 * })
 * // => { handled: true, reason: 'woke', bot: { id, name }, dryRun: true }
 */
export default async function handleEmailMessageReceived(
	input: HandleEmailMessageReceivedInput = {},
): Promise<Record<string, unknown>> {
	const dryRun = pickDryRun(input.dryRun)
	const unwrapped = unwrapEvent(plainClone(input) as HandleEmailMessageReceivedInput)
	const meta = plainClone(unwrapped.message)
	const messageId = typeof meta.id === 'string' ? meta.id.trim() : ''
	const aliases = plusAliasesFromMessage({
		to_addresses: meta.to_addresses,
		cc_addresses: meta.cc_addresses,
		bcc_addresses: meta.bcc_addresses,
	})

	if (!aliases.length) {
		return plainClone({
			subscriber: 'grok-bot',
			handled: false,
			reason: 'no-plus-alias',
			messageId: messageId || null,
		})
	}

	const full = (messageId ? await loadFullMessage(messageId) : null) ?? (meta as StoredEmail)
	const merged: StoredEmail = {
		...full,
		id: full.id || messageId,
		to_addresses: full.to_addresses?.length ? full.to_addresses : (meta.to_addresses as string[]),
		cc_addresses: full.cc_addresses?.length ? full.cc_addresses : (meta.cc_addresses as string[]),
		subject: full.subject ?? (typeof meta.subject === 'string' ? meta.subject : null),
		from_address: full.from_address ?? (typeof meta.from_address === 'string' ? meta.from_address : null),
		envelope_from: full.envelope_from ?? (typeof meta.envelope_from === 'string' ? meta.envelope_from : null),
		reply_to_addresses: full.reply_to_addresses?.length
			? full.reply_to_addresses
			: (meta.reply_to_addresses as string[] | undefined),
		thread_id: full.thread_id ?? (typeof meta.thread_id === 'string' ? meta.thread_id : null),
	}

	const kentFrom = isKentFrom(merged)
	const kentListed = kentOnThisMessage(merged)
	const threadId = typeof merged.thread_id === 'string' ? merged.thread_id.trim() : ''
	const bucket = packageStorage()
	let threadAlreadyOpen = false
	if (threadId) {
		try {
			threadAlreadyOpen = Boolean(
				await storageGet((key) => bucket.get(key), threadOpenKey(threadId)),
			)
		} catch {
			threadAlreadyOpen = false
		}
	}
	if (!kentFrom && !kentListed && !threadAlreadyOpen) {
		return plainClone({
			subscriber: 'grok-bot',
			handled: true,
			reason: 'ignored-cold-email',
			messageId: merged.id || messageId || null,
			from: merged.from_address ?? null,
		})
	}
	if (threadId) {
		try {
			await bucket.set(
				threadOpenKey(threadId),
				JSON.stringify({
					openedAt: new Date().toISOString(),
					from: merged.from_address ?? null,
				}),
			)
		} catch {
			// packageStorage may be Proxy-broken; continue without open-marker
		}
	}
	if (!kentFrom && threadId && dryRun !== true) {
		try {
			const rate = await storageGet((key) => bucket.get(key), threadRateKey(threadId))
			const throttled = consumeNonKentThreadThrottle(rate)
			try {
				await bucket.set(threadRateKey(threadId), JSON.stringify(throttled.state))
			} catch {
				/* ignore */
			}
			if (!throttled.ok) {
				return plainClone({
					subscriber: 'grok-bot',
					handled: true,
					reason: throttled.reason,
					messageId: merged.id || messageId || null,
					from: merged.from_address ?? null,
					threadId,
					lockedUntil: throttled.lockedUntil,
				})
			}
		} catch {
			// Skip throttle when storage is unusable.
		}
	}

	const eventAttachments = Array.isArray(unwrapped.attachments) ? unwrapped.attachments : []
	const storedAttachments: StoredAttachment[] = (
		merged.attachments?.length ? merged.attachments : eventAttachments
	).map((item) => {
		const row = asRecord(item) ?? {}
		return {
			id: typeof row.id === 'string' ? row.id : undefined,
			filename: typeof row.filename === 'string' ? row.filename : null,
			content_type: typeof row.content_type === 'string' ? row.content_type : null,
			size: typeof row.size === 'number' ? row.size : null,
		}
	})
	const withText: StoredAttachment[] = []
	for (const attachment of storedAttachments) {
		const text = await loadAttachmentText(attachment)
		withText.push({ ...attachment, ...(text ? { text } : {}) })
	}
	merged.attachments = withText

	const inboxId = typeof merged.inbox_id === 'string' && merged.inbox_id.trim() ? merged.inbox_id.trim() : undefined
	const [threadSnapshot, gmail] = await Promise.all([
		threadId
			? recentThread({ threadId, limit: 0, inbox_id: inboxId }).catch(() => ({
					count: 1,
					capped: false,
				}))
			: Promise.resolve({ count: 0, capped: false }),
		lookupGmail(merged),
	])

	const wakes: Array<Record<string, unknown>> = []
	const seenBots = new Set<string>()
	for (const alias of aliases) {
		let record = null
		for (const candidate of aliasCandidates(alias.tag)) {
			record = await resolveBot(candidate)
			if (record) break
		}
		if (!record) {
			wakes.push({
				alias: alias.address,
				tag: alias.tag,
				handled: false,
				reason: 'unknown-plus-alias',
			})
			continue
		}
		if (seenBots.has(record.id)) continue
		seenBots.add(record.id)

		const secret = await getSecretUseStatus(record.secretName)
		const pendingSecret = !secret.exists
		const hasUrl = Boolean(record.url)
		if (!hasUrl || pendingSecret) {
			wakes.push({
				alias: alias.address,
				tag: alias.tag,
				handled: true,
				reason: 'bot-not-registered-for-wake',
				bot: { id: record.id, name: record.name },
				pendingSecret,
				hasUrl,
			})
			continue
		}
		if (secret.needsHostApproval) {
			wakes.push({
				alias: alias.address,
				tag: alias.tag,
				handled: true,
				reason: 'host-approval-required',
				bot: { id: record.id, name: record.name },
				secretName: record.secretName,
				approvalUrl: secret.approvalUrl,
			})
			continue
		}

		const prompt = buildEmailPrompt({
			botName: record.name,
			alias,
			message: merged,
			threadCount: Math.max(threadSnapshot.count, threadId ? 1 : 0),
			threadCapped: threadSnapshot.capped === true,
			gmail,
			kentFrom,
		})
		const woke = await wake({
			bot: record.id,
			prompt,
			emailMessageId: merged.id,
			emailThreadId: merged.thread_id ?? undefined,
			emailAlias: alias.tag,
			emailAddress: alias.address,
			dryRun,
		})
		wakes.push({
			alias: alias.address,
			tag: alias.tag,
			handled: true,
			reason: isWakeTimedOut(woke) ? 'wake-timed-out' : 'woke',
			bot: { id: record.id, name: record.name },
			wake: woke,
		})
	}

	const handled = wakes.some((item) => item.handled === true)
	const reason =
		wakes.length === 1 && typeof wakes[0]?.reason === 'string'
			? wakes[0].reason
			: handled
				? 'woke'
				: 'unknown-plus-alias'
	return plainClone({
		subscriber: 'grok-bot',
		handled,
		reason,
		messageId: merged.id || messageId || null,
		dryRun,
		aliases: aliases.map((item: PlusAliasHit) => item.address),
		wakes,
	})
}