import { corsHeaders, handleCorsPreflightRequest } from '../_shared/cors.ts'
import { authErrorResponse, requireUser, type AuthError } from '../_shared/auth.ts'
import { createServiceRoleClient } from '../_shared/quota.ts'
import {
  MeetingDocumentRequestError,
  parseGenerateMeetingDocumentRequest,
} from '../_shared/meeting-document-contract.ts'
import { readProviderKey } from '../_shared/provider-key.ts'
import {
  generateMeetingDocument,
  type GenerationLogger,
  type MeetingDocumentProvider,
  type MeetingDocumentStore,
  type ProviderOutcome,
} from './generation.ts'

type ServiceClient = ReturnType<typeof createServiceRoleClient>

const PROVIDER_TIMEOUT_MS = 60_000

function json(status: number, body: Record<string, unknown>): Response {
  return new Response(JSON.stringify(body), {
    status,
    headers: {
      ...corsHeaders,
      'Content-Type': 'application/json',
      'Cache-Control': 'no-store',
    },
  })
}

const logError: GenerationLogger = (message, context) => {
  if (context === undefined) console.error(message)
  else console.error(message, context)
}

/** Supabase adapter for the persistence port (service-role RPCs). */
function createSupabaseStore(client: ServiceClient): MeetingDocumentStore {
  return {
    async claim(actorId, request) {
      const { data, error } = await client.rpc('claim_meeting_document_generation_v1', {
        p_actor_id: actorId,
        p_idempotency_key: request.idempotencyKey,
        p_meeting_id: request.meetingId,
        p_template_id: request.templateId,
        p_title: request.title,
        p_model: request.model,
      })
      return { data, error }
    },
    async markFailed(actorId, idempotencyKey, code) {
      const { error } = await client.rpc('fail_meeting_document_generation_v1', {
        p_actor_id: actorId,
        p_idempotency_key: idempotencyKey,
        p_error_code: code,
      })
      return error
    },
    async commit(actorId, idempotencyKey, providerResult, latencyMs) {
      const { data, error } = await client.rpc('commit_meeting_document_generation_v1', {
        p_actor_id: actorId,
        p_idempotency_key: idempotencyKey,
        p_content: providerResult.content,
        p_latency_ms: latencyMs,
        p_input_tokens: providerResult.inputTokens,
        p_output_tokens: providerResult.outputTokens,
      })
      return { data, error }
    },
    async findDocument(actorId, documentId) {
      const { data, error } = await client
        .from('meeting_documents')
        .select('*')
        .eq('id', documentId)
        .eq('user_id', actorId)
        .maybeSingle()
      return { data, error }
    },
  }
}

/** Anthropic Messages API adapter for the provider port. */
function createAnthropicProvider(apiKey: string): MeetingDocumentProvider {
  return {
    async generate(payload): Promise<ProviderOutcome> {
      let response: Response
      try {
        response = await fetch('https://api.anthropic.com/v1/messages', {
          method: 'POST',
          headers: {
            'Content-Type': 'application/json',
            'x-api-key': apiKey,
            'anthropic-version': '2023-06-01',
          },
          body: JSON.stringify(payload),
          signal: AbortSignal.timeout(PROVIDER_TIMEOUT_MS),
        })
      } catch (error) {
        const timedOut = error instanceof DOMException && error.name === 'TimeoutError'
        return timedOut ? { kind: 'timeout' } : { kind: 'network_error' }
      }
      if (!response.ok) return { kind: 'http_error', status: response.status }
      try {
        return { kind: 'ok', body: await response.json() }
      } catch {
        return { kind: 'ok', body: null }
      }
    },
  }
}

Deno.serve(async (request: Request) => {
  const preflight = handleCorsPreflightRequest(request)
  if (preflight) return preflight
  if (request.method !== 'POST') return json(405, { error: 'method_not_allowed' })

  try {
    const actor = await requireUser(request)

    let rawBody: unknown
    try {
      rawBody = await request.json()
    } catch {
      throw new MeetingDocumentRequestError('Invalid JSON body')
    }
    const body = parseGenerateMeetingDocumentRequest(rawBody)

    const providerKey = readProviderKey('ANTHROPIC_API_KEY')
    if (providerKey.length === 0) {
      return json(503, { error: 'provider_unavailable' })
    }

    const outcome = await generateMeetingDocument(actor.id, body, {
      store: createSupabaseStore(createServiceRoleClient()),
      provider: createAnthropicProvider(providerKey),
      now: () => Date.now(),
      log: logError,
    })
    return json(outcome.status, outcome.body)
  } catch (error) {
    if (error instanceof MeetingDocumentRequestError) {
      return json(error.status, { error: 'invalid_request', message: error.message })
    }
    if (error && typeof error === 'object' && 'status' in error && 'message' in error) {
      return authErrorResponse(error as AuthError, corsHeaders)
    }
    console.error('generate-meeting-document failed', { kind: 'internal_error' })
    return json(500, { error: 'internal_error' })
  }
})