import fs from 'fs'
import path from 'path'
import { applyPatchToDir } from '@pnpm/patching.apply-patch'
import { docsUrl } from '@pnpm/cli-utils'
import { Config, types as allTypes } from '@pnpm/config'
import { LogBase } from '@pnpm/logger'
import {
  CreateStoreControllerOptions,
} from '@pnpm/store-connection-manager'
import pick from 'ramda/src/pick'
import renderHelp from 'render-help'
import tempy from 'tempy'
import { PnpmError } from '@pnpm/error'
import { writePackage, ParseWantedDependencyResult } from './writePackage'

export function rcOptionsTypes () {
  return pick([], allTypes)
}

export function cliOptionsTypes () {
  return { ...rcOptionsTypes(), 'edit-dir': String, 'ignore-existing': Boolean }
}

export const shorthands = {
  d: '--edit-dir',
}

export const commandNames = ['patch']

export function help () {
  return renderHelp({
    description: 'Prepare a package for patching',
    descriptionLists: [{
      title: 'Options',
      list: [
        {
          description: 'The package that needs to be modified will be extracted to this directory',
          name: '--edit-dir',
        },
        {
          description: 'Ignore existing patch files when patching',
          name: '--ignore-existing',
        },
      ],
    }],
    url: docsUrl('patch'),
    usages: ['pnpm patch <pkg name>@<version>'],
  })
}

export type PatchCommandOptions = Pick<Config, 'dir' | 'registries' | 'tag' | 'storeDir' | 'rootProjectManifest' | 'lockfileDir'> & CreateStoreControllerOptions & {
  editDir?: string
  reporter?: (logObj: LogBase) => void
  ignoreExisting?: boolean
}

export async function handler (opts: PatchCommandOptions, params: string[]) {
  if (opts.editDir && fs.existsSync(opts.editDir) && fs.readdirSync(opts.editDir).length > 0) {
    throw new PnpmError('PATCH_EDIT_DIR_EXISTS', `The target directory already exists: '${opts.editDir}'`)
  }
  const editDir = opts.editDir ?? tempy.directory()
  const patchedDep = await writePackage(params[0], editDir, opts)
  if (!opts.ignoreExisting && opts.rootProjectManifest?.pnpm?.patchedDependencies) {
    tryPatchWithExistingPatchFile({
      patchedDep,
      patchedDir: editDir,
      patchedDependencies: opts.rootProjectManifest.pnpm.patchedDependencies,
      lockfileDir: opts.lockfileDir ?? opts.dir ?? process.cwd(),
    })
  }
  return `You can now edit the following folder: ${editDir}

Once you're done with your changes, run "pnpm patch-commit ${editDir}"`
}

function tryPatchWithExistingPatchFile (
  {
    patchedDep,
    patchedDir,
    patchedDependencies,
    lockfileDir,
  }: {
    patchedDep: ParseWantedDependencyResult
    patchedDir: string
    patchedDependencies: Record<string, string>
    lockfileDir: string
  }
) {
  if (!patchedDep.alias || !patchedDep.pref) {
    return
  }
  const existingPatchFile = patchedDependencies[`${patchedDep.alias}@${patchedDep.pref}`]
  if (!existingPatchFile) {
    return
  }
  const existingPatchFilePath = path.resolve(lockfileDir, existingPatchFile)
  if (!fs.existsSync(existingPatchFilePath)) {
    throw new PnpmError('PATCH_FILE_NOT_FOUND', `Unable to find patch file ${existingPatchFilePath}`)
  }
  applyPatchToDir({ patchedDir, patchFilePath: existingPatchFilePath })
}