import { resolve } from 'node:path'
import Fastify from 'fastify'
import {
  serializerCompiler,
  validatorCompiler,
  type ZodTypeProvider,
} from '@fastify/type-provider-zod'
import { AsyncTask, CronJob } from 'toad-scheduler'
import type { AppConfig } from './config.js'
import { loadConfig } from './config.js'
import authPlugin from './plugins/auth.js'
import operationalPlugin from './plugins/operational.js'
import corsPlugin from './plugins/cors.js'
import dbPlugin from './plugins/db.js'
import errorHandlerPlugin from './plugins/error-handler.js'
import { healthRoutes } from './routes/health.js'
import { controlRoutes } from './routes/control.js'
import { auditRoutes } from './routes/audit.js'
import { agentRoutes } from './routes/agent.js'
import { enrollmentRoutes } from './routes/enrollment.js'
import { policyRolloutsRoutes } from './routes/policy-rollouts.js'
import { webhooksRoutes } from './routes/webhooks.js'
import { refreshAllLists } from './services/lists/refresh.js'
import { runStatsRetention } from './services/analytics.js'
import { repos } from '@evofw/db'
import {
  isValidInstallSlug,
  resolveAndRenderInstall,
} from './services/install-links.js'

export interface BuildAppOptions {
  config?: AppConfig
  memory?: boolean
}

export async function buildApp(opts: BuildAppOptions = {}) {
  const config = opts.config ?? loadConfig()

  const app = Fastify({
    trustProxy: config.trustProxy ?? false,
    logger: { level: config.logLevel },
    genReqId: () => crypto.randomUUID(),
  }).withTypeProvider<ZodTypeProvider>()

  // Correlation id in every response and in the error envelope.
  app.addHook('onSend', async (req, reply) => {
    reply.header('x-request-id', req.id)
  })

  app.setValidatorCompiler(validatorCompiler)
  app.setSerializerCompiler(serializerCompiler)

  await app.register(import('@fastify/sensible'))
  // CSP only guards the served SPA; in dev the Vite server proxies API
  // requests same-origin and injects its own HMR scripts.
  await app.register(import('@fastify/helmet'), {
    contentSecurityPolicy:
      config.staticDir !== null
        ? {
            directives: {
              defaultSrc: ["'self'"],
              scriptSrc: ["'self'"],
              styleSrc: ["'self'", "'unsafe-inline'"],
              imgSrc: ["'self'", 'data:'],
              fontSrc: ["'self'", 'data:'],
              // app-switcher talks to the auth portal directly from the browser
              connectSrc: ["'self'", config.authPortalUrl],
              objectSrc: ["'none'"],
              baseUri: ["'self'"],
              frameAncestors: ["'none'"],
            },
          }
        : false,
  })
  await app.register(corsPlugin, { config })
  await app.register(errorHandlerPlugin)
  await app.register(dbPlugin, { config, memory: opts.memory })
  await app.register(authPlugin, { config })
  await app.register(operationalPlugin, { config, memory: opts.memory })

  // Seed enroll_seed into settings if empty
  if (!repos.getSetting(app.db, 'enroll_seed')) {
    repos.setSetting(app.db, 'enroll_seed', config.enrollSeed)
  }

  await app.register(healthRoutes)
  await app.register(agentRoutes, { config })
  await app.register(enrollmentRoutes, { config })

  await app.register(
    async (protectedApi) => {
      protectedApi.addHook('onRequest', app.requireAuth)
      await protectedApi.register(controlRoutes, { config })
      await protectedApi.register(auditRoutes)
      await protectedApi.register(policyRolloutsRoutes, { config })
      await protectedApi.register(webhooksRoutes, { config, memory: opts.memory })
    },
    { prefix: '/api/v1' },
  )

  const staticDir = config.staticDir ?? resolve(process.cwd(), 'static')
  if (config.staticDir !== null) {
    await app.register(import('@fastify/static'), {
      root: staticDir,
      wildcard: false,
    })
  }

  app.setNotFoundHandler(async (request, reply) => {
    const path = request.url.split('?')[0] ?? ''
    if (path === '/api' || path.startsWith('/api/') || path === '/v1' || path.startsWith('/v1/')) {
      return reply.code(404).send({ error: { code: 'NOT_FOUND', message: 'Not Found', request_id: request.id } })
    }
    const segment = path.startsWith('/') ? path.slice(1) : path
    if (
      request.method === 'GET' &&
      segment &&
      !segment.includes('/') &&
      isValidInstallSlug(segment)
    ) {
      const link = repos.getInstallLinkBySlug(app.db, segment)
      if (link) {
        const { body, contentType } = resolveAndRenderInstall(
          app.db,
          link,
          config.publicBaseUrl,
          config.enrollSeed,
        )
        return reply.header('Cache-Control', 'no-store').type(contentType).send(body)
      }
    }

    if (config.staticDir !== null) {
      return reply.sendFile('index.html')
    }
    return reply.code(404).send({
      error: { code: 'NOT_FOUND', message: 'Not Found' },
    })
  })

  if (!opts.memory) {
    await app.register(import('@fastify/schedule'))
    const task = new AsyncTask(
      'list-refresh',
      async () => {
        await refreshAllLists(app.db)
        app.log.info('list refresh completed')
      },
      (err) => {
        app.log.warn({ err }, 'list refresh failed')
      },
    )
    app.scheduler.addCronJob(
      new CronJob({ cronExpression: '0 */5 * * * *' }, task, {
        preventOverrun: true,
      }),
    )

    // Raw stats samples grow ~1 row per agent per sync interval; drop old
    // ones daily. Lifetime totals live on agents; aggregates are kept.
    const retentionAbort = new AbortController()
    app.addHook('onClose', async () => { retentionAbort.abort() })
    const runRetention = async () => {
      const deleted = await runStatsRetention(app.db, new Date().toISOString(), 1000, retentionAbort.signal)
      if (deleted > 0) app.log.info({ deleted }, 'stats retention completed')
    }
    app.scheduler.addCronJob(
      new CronJob(
        { cronExpression: '17 * * * *' },
        new AsyncTask('stats-retention', runRetention, (err) => {
          app.log.warn({ err }, 'stats retention failed')
        }),
        { preventOverrun: true },
      ),
    )
    // First cleanup right at startup, not only after the next 03:17.
    runRetention().catch((err) =>
      app.log.warn({ err }, 'stats retention failed'),
    )
  }

  return app
}