import { basename, resolve } from 'node:path'

import { isBase64, isDemoFilePath } from './file-helpers.js'
import { formatCommand } from './utils.js'
import { writeConfigFileToEnvironment } from './config-file.js'
import {
  getPackageManagerScriptCommand,
  intentCommand,
  packageManagerInstall,
  translateExecuteCommand,
  validatePackageManagerSupport,
} from './package-manager.js'
import { createPackageJSON } from './package-json.js'
import { resolvePackageJSONLatest } from './npm-resolver.js'
import { createTemplateFile } from './template-file.js'
import { installShadcnComponents } from './integrations/shadcn.js'
import { setupGit } from './integrations/git.js'
import { setupIntent } from './integrations/intent.js'
import { runSpecialSteps } from './special-steps/index.js'

import type { Environment, FileBundleHandler, Options } from './types.js'

function stripExamplesFromOptions(options: Options): Options {
  const includeExamples =
    options.projectPreset !== 'blank' && options.includeExamples !== false

  if (includeExamples) {
    return options
  }

  const chosenAddOns = options.chosenAddOns
    .filter((addOn) => addOn.type !== 'example')
    .map((addOn) => {
      const filteredRoutes = (addOn.routes || []).filter(
        (route) =>
          !isDemoFilePath(route.path) &&
          !(route.url && route.url.startsWith('/demo')),
      )

      const filteredIntegrations = (addOn.integrations || []).filter(
        (integration) => !isDemoFilePath(integration.path)
      )

      return {
        ...addOn,
        routes: filteredRoutes,
        integrations: filteredIntegrations,
        getFiles: async () => {
          const files = await addOn.getFiles()
          return files.filter((file) => !isDemoFilePath(file))
        },
        getDeletedFiles: async () => {
          const deletedFiles = await addOn.getDeletedFiles()
          return deletedFiles.filter((file) => !isDemoFilePath(file))
        },
      }
    })

  return {
    ...options,
    includeExamples: false,
    chosenAddOns,
  }
}

async function writeFiles(environment: Environment, options: Options) {
  const templateFileFromContent = createTemplateFile(environment, options)

  async function writeFileBundle(bundle: FileBundleHandler) {
    const files = await bundle.getFiles()

    for (const file of files) {
      const contents = await bundle.getFileContents(file)

      const isBinaryFile = isBase64(contents)
      if (isBinaryFile) {
        await environment.writeFileBase64(
          resolve(options.targetDir, file),
          contents,
        )
      } else {
        await templateFileFromContent(file, contents)
      }
    }

    const deletedFiles = await bundle.getDeletedFiles()
    for (const file of deletedFiles) {
      await environment.deleteFile(resolve(options.targetDir, file))
    }
  }

  environment.startStep({
    id: 'write-framework-files',
    type: 'file',
    message: 'Writing framework files...',
  })
  await writeFileBundle(options.framework)
  environment.finishStep('write-framework-files', 'Framework files written')

  let wroteAddonFiles = false
  for (const type of ['add-on', 'example', 'toolchain', 'deployment']) {
    for (const phase of ['setup', 'add-on', 'example']) {
      for (const addOn of options.chosenAddOns.filter(
        (addOn) => addOn.phase === phase && addOn.type === type,
      )) {
        environment.startStep({
          id: 'write-addon-files',
          type: 'file',
          message: `Writing ${addOn.name} files...`,
        })
        await writeFileBundle(addOn)
        wroteAddonFiles = true
      }
    }
  }
  if (wroteAddonFiles) {
    environment.finishStep('write-addon-files', 'Add-on files written')
  }

  if (options.starter) {
    environment.startStep({
      id: 'write-starter-files',
      type: 'file',
      message: 'Writing starter files...',
    })
    await writeFileBundle(options.starter)
    environment.finishStep('write-starter-files', 'Starter files written')
  }

  environment.startStep({
    id: 'write-package-json',
    type: 'file',
    message: 'Writing package.json...',
  })
  const packageJSON = await resolvePackageJSONLatest(createPackageJSON(options))
  await environment.writeFile(
    resolve(options.targetDir, './package.json'),
    JSON.stringify(packageJSON, null, 2),
  )
  environment.finishStep('write-package-json', 'Package.json written')

  environment.startStep({
    id: 'write-config-file',
    type: 'file',
    message: 'Writing config file...',
  })
  await writeConfigFileToEnvironment(environment, options)
  environment.finishStep('write-config-file', 'Config file written')
}

async function runCommandsAndInstallDependencies(
  environment: Environment,
  options: Options,
) {
  const s = environment.spinner()

  // Setup git
  if (options.git) {
    s.start(`Initializing git repository...`)
    environment.startStep({
      id: 'initialize-git-repository',
      type: 'command',
      message: 'Initializing git repository...',
    })

    await setupGit(environment, options.targetDir)

    environment.finishStep(
      'initialize-git-repository',
      'Initialized git repository',
    )
    s.stop(`Initialized git repository`)
  }

  // Run any special steps for the new add-ons
  const specialSteps = new Set<string>([])
  for (const addOn of options.chosenAddOns) {
    for (const step of addOn.createSpecialSteps || []) {
      specialSteps.add(step)
    }
  }
  if (specialSteps.size) {
    await runSpecialSteps(environment, options, Array.from(specialSteps))
  }

  // Install dependencies
  if (options.install !== false) {
    s.start(`Installing dependencies via ${options.packageManager}...`)
    environment.startStep({
      id: 'install-dependencies',
      type: 'package-manager',
      message: `Installing dependencies via ${options.packageManager}...`,
    })
    await packageManagerInstall(
      environment,
      options.targetDir,
      options.packageManager,
    )
    environment.finishStep('install-dependencies', 'Installed dependencies')
    s.stop(`Installed dependencies`)
  } else {
    s.start(`Skipping dependency installation...`)
    environment.startStep({
      id: 'skip-dependencies',
      type: 'info',
      message: `Skipping dependency installation...`,
    })
    environment.finishStep('skip-dependencies', 'Dependency installation skipped')
    s.stop(`Dependency installation skipped`)
  }

  // Run any post-init special steps for the new add-ons
  const postInitSpecialSteps = new Set<string>([])
  for (const addOn of options.chosenAddOns) {
    for (const step of addOn.postInitSpecialSteps || []) {
      postInitSpecialSteps.add(step)
    }
  }
  if (postInitSpecialSteps.size) {
    await runSpecialSteps(
      environment,
      options,
      Array.from(postInitSpecialSteps),
    )
  }

  for (const phase of ['setup', 'add-on', 'example']) {
    for (const addOn of options.chosenAddOns.filter(
      (addOn) =>
        addOn.phase === phase && addOn.command && addOn.command.command,
    )) {
      s.start(`Running commands for ${addOn.name}...`)
      const translated = translateExecuteCommand(options.packageManager, {
        command: addOn.command!.command,
        args: addOn.command!.args || [],
      })
      const cmd = formatCommand(translated)
      environment.startStep({
        id: 'run-commands',
        type: 'command',
        message: cmd,
      })
      await environment.execute(
        translated.command,
        translated.args,
        options.targetDir,
        { inherit: true },
      )
      environment.finishStep('run-commands', 'Setup commands complete')
      s.stop(`${addOn.name} commands complete`)
    }
  }

  // Adding starter
  if (
    options.starter &&
    options.starter.command &&
    options.starter.command.command
  ) {
    s.start(`Setting up starter ${options.starter.name}...`)
    const starterTranslated = translateExecuteCommand(options.packageManager, {
      command: options.starter.command.command,
      args: options.starter.command.args || [],
    })
    const cmd = formatCommand(starterTranslated)
    environment.startStep({
      id: 'run-starter-command',
      type: 'command',
      message: cmd,
    })

    await environment.execute(
      starterTranslated.command,
      starterTranslated.args,
      options.targetDir,
      { inherit: true },
    )

    environment.finishStep('run-starter-command', 'Starter command complete')
    s.stop(`${options.starter.name} commands complete`)
  }

  await installShadcnComponents(environment, options.targetDir, options)

  await setupIntent(environment, options.targetDir, options)

  if (shouldGenerateRoutes(options)) {
    s.start(`Generating route tree...`)
    const command = getPackageManagerScriptCommand(options.packageManager, [
      'generate-routes',
    ])
    const cmd = formatCommand(command)
    environment.startStep({
      id: 'generate-routes',
      type: 'command',
      message: cmd,
    })
    await environment.execute(
      command.command,
      command.args,
      options.targetDir,
      {
        inherit: true,
      },
    )
    environment.finishStep('generate-routes', 'Route tree generated')
    s.stop(`Route tree generated`)
  }
}

function shouldGenerateRoutes(options: Options) {
  return (
    options.install !== false &&
    options.mode === 'file-router' &&
    (options.framework.id === 'react' || options.framework.id === 'solid')
  )
}

async function seedEnvValues(environment: Environment, options: Options) {
  const envVarValues = options.envVarValues || {}
  const entries = Object.entries(envVarValues)
  if (entries.length === 0) return

  const envLocalPath = resolve(options.targetDir, '.env.local')
  if (!environment.exists(envLocalPath)) {
    return
  }

  let envContents = await environment.readFile(envLocalPath)
  for (const [key, value] of entries) {
    const escapedValue = value.replace(/\n/g, '\\n')
    const nextLine = `${key}=${escapedValue}`
    const pattern = new RegExp(`^${key}=.*$`, 'm')

    if (pattern.test(envContents)) {
      envContents = envContents.replace(pattern, nextLine)
    } else {
      envContents += `${envContents.endsWith('\n') ? '' : '\n'}${nextLine}\n`
    }
  }

  await environment.writeFile(envLocalPath, envContents)
}

async function writeEnvExample(environment: Environment, options: Options) {
  const envExamplePath = resolve(options.targetDir, '.env.example')
  const existing = environment.exists(envExamplePath)
    ? await environment.readFile(envExamplePath)
    : ''

  const declared = new Set<string>()
  for (const match of existing.matchAll(/^([A-Z_][A-Z0-9_]*)=/gm)) {
    declared.add(match[1])
  }

  const sections: Array<string> = []
  for (const addOn of options.chosenAddOns) {
    const lines: Array<string> = []
    for (const envVar of addOn.envVars || []) {
      if (declared.has(envVar.name)) continue
      declared.add(envVar.name)
      if (envVar.description) {
        const required = envVar.required ? ' (required)' : ''
        lines.push(`# ${envVar.description}${required}`)
      }
      lines.push(`${envVar.name}=`)
    }
    if (lines.length > 0) {
      sections.push(`# ${addOn.name}\n${lines.join('\n')}`)
    }
  }

  if (sections.length === 0) return

  const additions = sections.join('\n\n')
  const newContent = existing
    ? `${existing.trimEnd()}\n\n${additions}\n`
    : `${additions}\n`

  await environment.writeFile(envExamplePath, newContent)
}

const SHIPPING_CATEGORIES = new Set(['auth', 'database', 'orm', 'deploy'])

function buildNextSteps(options: Options): string {
  const collectedEnv = new Set(Object.keys(options.envVarValues || {}))
  const listedEnvVars = new Set<string>()
  const envVarLines: Array<string> = []
  const docLines: Array<string> = []

  for (const addOn of options.chosenAddOns) {
    if (addOn.link && addOn.category && SHIPPING_CATEGORIES.has(addOn.category)) {
      docLines.push(`  • ${addOn.name} (${addOn.category}) — ${addOn.link}`)
    }

    for (const envVar of addOn.envVars || []) {
      if (listedEnvVars.has(envVar.name)) continue
      listedEnvVars.add(envVar.name)
      const required = envVar.required ? ' (required)' : ''
      const status = collectedEnv.has(envVar.name)
        ? ' — already set from your input'
        : ' — needs a value'
      const desc = envVar.description ? ` — ${envVar.description}` : ''
      envVarLines.push(`  • ${envVar.name}${required}${desc}${status}`)
    }
  }

  const sections: Array<string> = []
  if (envVarLines.length > 0) {
    sections.push(
      `Environment variables (review/fill in .env.local before deploying):\n${envVarLines.join('\n')}`,
    )
  }
  if (docLines.length > 0) {
    sections.push(`Docs for the integrations you picked:\n${docLines.join('\n')}`)
  }
  if (options.intent) {
    sections.push(
      `Working with an AI agent? Your agent config (AGENTS.md / CLAUDE.md) was wired up by TanStack Intent\nso your agent can discover skills for the libraries you installed, on demand:\n  • ${intentCommand(options.packageManager, ['list'])}\n  • ${intentCommand(options.packageManager, ['load', '<package>#<skill>'])}\nTry asking your agent:\n  • "migrate this Next.js page to TanStack Start"\n  • "add a protected /dashboard route"\n  • "show me how to use TanStack Router search params"`,
    )
  }

  return sections.length > 0 ? `\nNext steps:\n\n${sections.join('\n\n')}\n` : ''
}

function report(environment: Environment, options: Options) {
  const warnings: Array<string> = []
  for (const addOn of options.chosenAddOns) {
    if (addOn.warning) {
      warnings.push(addOn.warning)
    }
  }

  if (warnings.length > 0) {
    environment.warn('Warnings', warnings.join('\n'))
  }

  // Format errors
  let errorStatement = ''
  if (environment.getErrors().length) {
    errorStatement = `

Errors were encountered during the creation of your app:

${environment.getErrors().join('\n')}`
  }

  // Check if we created in current directory (user specified ".")
  const isCurrentDirectory =
    resolve(options.targetDir) === resolve(process.cwd())
  const locationMessage = isCurrentDirectory
    ? `Your ${environment.appName} app is ready.`
    : `Your ${environment.appName} app is ready in '${basename(options.targetDir)}'.`
  const cdInstruction = isCurrentDirectory
    ? ''
    : `% cd ${options.projectName}
`

  const nextSteps = buildNextSteps(options)
  const readmeDescription =
    options.projectPreset === 'blank'
      ? 'running, building, adding routes, and selected integrations.'
      : 'testing, styling, adding routes, etc.'

  // Use the force luke! :)
  environment.outro(
    `${locationMessage}

Use the following commands to start your app:
${cdInstruction}% ${formatCommand(
      getPackageManagerScriptCommand(options.packageManager, ['dev']),
    )}
${nextSteps}
Please read the README.md file for information on ${readmeDescription}${errorStatement}`,
  )
}

export async function createApp(environment: Environment, options: Options) {
  validatePackageManagerSupport(options.packageManager, options.chosenAddOns)
  const effectiveOptions = stripExamplesFromOptions(options)

  environment.startRun()
  await writeFiles(environment, effectiveOptions)
  await seedEnvValues(environment, effectiveOptions)
  await writeEnvExample(environment, effectiveOptions)
  await runCommandsAndInstallDependencies(environment, effectiveOptions)
  environment.finishRun()

  report(environment, effectiveOptions)
}