import path from 'node:path'
import { execSync } from 'node:child_process'
import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'
import tailwindcss from '@tailwindcss/vite'

const MAX_TEAM_NAME_LENGTH = 80

function siteVersion() {
  try {
    const count = execSync('git rev-list --count HEAD', {
      cwd: __dirname,
      encoding: 'utf8',
      stdio: ['ignore', 'pipe', 'ignore'],
    }).trim()
    return `1.0.${Number(count) || 0}`
  } catch {
    return '1.0.0'
  }
}

function isAllowedApiUrl(req) {
  const url = new URL(req.url, 'http://localhost')
  const params = url.searchParams

  if (url.pathname === '/api/viewers' && (req.method === 'GET' || req.method === 'HEAD')) return true
  if (url.pathname === '/api/viewers/event' && req.method === 'POST') return true

  if (req.method !== 'GET' && req.method !== 'HEAD') return false

  if (url.pathname === '/api/tss/tournaments') return true
  if (/^\/api\/tss\/tournaments\/[^/]+$/.test(url.pathname)) return true

  if (url.pathname === '/api/tss/leaderboard/teams') {
    const keys = [...params.keys()]
    const limit = Number(params.get('limit') || 100)
    return keys.every((key) => key === 'limit') && Number.isInteger(limit) && limit >= 1 && limit <= 100
  }

  if (url.pathname === '/api/tss/leaderboard/players') {
    const keys = [...params.keys()]
    const limit = Number(params.get('limit') || 100)
    return keys.every((key) => key === 'limit') && Number.isInteger(limit) && limit >= 1 && limit <= 100
  }

  if (url.pathname === '/api/tss/games/recent') {
    const keys = [...params.keys()]
    const limit = Number(params.get('limit') || 50)
    return keys.every((key) => key === 'limit') && Number.isInteger(limit) && limit >= 1 && limit <= 100
  }

  if (/^\/api\/tss\/games\/[A-Za-z0-9_-]{1,96}$/.test(url.pathname)) {
    const keys = [...params.keys()]
    const lang = params.get('lang') || 'en'
    return keys.every((key) => key === 'lang') && /^[A-Za-z-]{2,8}$/.test(lang)
  }

  if (/^\/api\/tss\/games\/[A-Za-z0-9_-]{1,96}\/logs$/.test(url.pathname)) {
    return [...params.keys()].length === 0
  }

  if (url.pathname === '/api/tss/teams/resolve') {
    const keys = [...params.keys()]
    const name = params.get('name') || ''
    return keys.every((key) => key === 'name') && name.length >= 2 && name.length <= MAX_TEAM_NAME_LENGTH
  }

  if (url.pathname === '/api/tss/teams/search') {
    const keys = [...params.keys()]
    const query = params.get('q') || params.get('name') || ''
    const limit = Number(params.get('limit') || 10)
    return (
      keys.every((key) => ['q', 'name', 'limit'].includes(key)) &&
      query.length >= 2 &&
      query.length <= MAX_TEAM_NAME_LENGTH &&
      Number.isInteger(limit) &&
      limit >= 1 &&
      limit <= 20
    )
  }

  if (url.pathname === '/api/tss/players/search') {
    const keys = [...params.keys()]
    const query = params.get('q') || params.get('name') || ''
    const limit = Number(params.get('limit') || 25)
    return (
      keys.every((key) => ['q', 'name', 'limit'].includes(key)) &&
      query.length >= 2 &&
      query.length <= MAX_TEAM_NAME_LENGTH &&
      Number.isInteger(limit) &&
      limit >= 1 &&
      limit <= 25
    )
  }

  if (/^\/api\/tss\/player\/[0-9]{1,32}$/.test(url.pathname)) {
    return [...params.keys()].length === 0
  }

  if ([...params.keys()].length) return false

  try {
    const match = url.pathname.match(/^\/api\/tss\/teams\/([^/]+)(?:\/(history|games))?$/)
    const teamName = match ? decodeURIComponent(match[1]) : ''
    return Boolean(teamName) && teamName.length <= MAX_TEAM_NAME_LENGTH
  } catch {
    return false
  }
}

function apiGuard() {
  return {
    name: 'api-guard',
    configureServer(server) {
      server.middlewares.use(async (req, res, next) => {
        if (!req.url?.startsWith('/api/')) {
          next()
          return
        }

        if (isAllowedApiUrl(req)) {
          next()
          return
        }

        res.writeHead(404, {
          'content-type': 'application/json; charset=utf-8',
          'x-content-type-options': 'nosniff',
        })
        res.end(JSON.stringify({ error: 'API route not found' }))
      })
    },
  }
}

export default defineConfig(() => {
  return {
    root: path.resolve(__dirname, 'frontend'),
    publicDir: path.resolve(__dirname, 'frontend/public'),
    plugins: [apiGuard(), react(), tailwindcss()],
    define: {
      'import.meta.env.VITE_SITE_VERSION': JSON.stringify(siteVersion()),
    },
    build: {
      outDir: path.resolve(__dirname, 'dist'),
      emptyOutDir: true,
    },
    server: {
      host: '0.0.0.0',
      port: 3001,
      proxy: {
        '/api': {
          target: process.env.VITE_API_TARGET ?? 'http://localhost:6000',
          changeOrigin: true,
        },
        '/health': {
          target: process.env.VITE_API_TARGET ?? 'http://localhost:6000',
          changeOrigin: true,
        },
      },
    },
  }
})
