/**
 * @typedef {import('unist').Node} Node
 * @typedef {import('unist').Position} Position
 * @typedef {import('unist').Point} Point
 * @typedef {import('./minurl.shared.js').URL} URL
 * @typedef {import('../index.js').Data} Data
 * @typedef {import('../index.js').Value} Value
 */

/**
 * @typedef {Record<string, unknown> & {type: string, position?: Position | undefined}} NodeLike
 *
 * @typedef {'ascii' | 'utf8' | 'utf-8' | 'utf16le' | 'ucs2' | 'ucs-2' | 'base64' | 'base64url' | 'latin1' | 'binary' | 'hex'} BufferEncoding
 *   Encodings supported by the buffer class.
 *
 *   This is a copy of the types from Node, copied to prevent Node globals from
 *   being needed.
 *   Copied from: <https://github.com/DefinitelyTyped/DefinitelyTyped/blob/90a4ec8/types/node/buffer.d.ts#L170>
 *
 * @typedef {Options | URL | Value | VFile} Compatible
 *   Things that can be passed to the constructor.
 *
 * @typedef VFileCoreOptions
 *   Set multiple values.
 * @property {Value | null | undefined} [value]
 *   Set `value`.
 * @property {string | null | undefined} [cwd]
 *   Set `cwd`.
 * @property {Array<string> | null | undefined} [history]
 *   Set `history`.
 * @property {URL | string | null | undefined} [path]
 *   Set `path`.
 * @property {string | null | undefined} [basename]
 *   Set `basename`.
 * @property {string | null | undefined} [stem]
 *   Set `stem`.
 * @property {string | null | undefined} [extname]
 *   Set `extname`.
 * @property {string | null | undefined} [dirname]
 *   Set `dirname`.
 * @property {Data | null | undefined} [data]
 *   Set `data`.
 *
 * @typedef Map
 *   Raw source map.
 *
 *   See:
 *   <https://github.com/mozilla/source-map/blob/58819f0/source-map.d.ts#L15-L23>.
 * @property {number} version
 *   Which version of the source map spec this map is following.
 * @property {Array<string>} sources
 *   An array of URLs to the original source files.
 * @property {Array<string>} names
 *   An array of identifiers which can be referenced by individual mappings.
 * @property {string | undefined} [sourceRoot]
 *   The URL root from which all sources are relative.
 * @property {Array<string> | undefined} [sourcesContent]
 *   An array of contents of the original source files.
 * @property {string} mappings
 *   A string of base64 VLQs which contain the actual mappings.
 * @property {string} file
 *   The generated file this source map is associated with.
 *
 * @typedef {{[key: string]: unknown} & VFileCoreOptions} Options
 *   Configuration.
 *
 *   A bunch of keys that will be shallow copied over to the new file.
 *
 * @typedef {Record<string, unknown>} ReporterSettings
 *   Configuration for reporters.
 */

/**
 * @template {ReporterSettings} Settings
 *   Options type.
 * @callback Reporter
 *   Type for a reporter.
 * @param {Array<VFile>} files
 *   Files to report.
 * @param {Settings} options
 *   Configuration.
 * @returns {string}
 *   Report.
 */

import bufferLike from 'is-buffer'
import {VFileMessage} from 'vfile-message'
import {path} from './minpath.js'
import {proc} from './minproc.js'
import {urlToPath, isUrl} from './minurl.js'

/**
 * Order of setting (least specific to most), we need this because otherwise
 * `{stem: 'a', path: '~/b.js'}` would throw, as a path is needed before a
 * stem can be set.
 *
 * @type {Array<'basename' | 'dirname' | 'extname' | 'history' | 'path' | 'stem'>}
 */
const order = ['history', 'path', 'basename', 'stem', 'extname', 'dirname']

export class VFile {
  /**
   * Create a new virtual file.
   *
   * `options` is treated as:
   *
   * *   `string` or `Buffer` — `{value: options}`
   * *   `URL` — `{path: options}`
   * *   `VFile` — shallow copies its data over to the new file
   * *   `object` — all fields are shallow copied over to the new file
   *
   * Path related fields are set in the following order (least specific to
   * most specific): `history`, `path`, `basename`, `stem`, `extname`,
   * `dirname`.
   *
   * You cannot set `dirname` or `extname` without setting either `history`,
   * `path`, `basename`, or `stem` too.
   *
   * @param {Compatible | null | undefined} [value]
   *   File value.
   * @returns
   *   New instance.
   */
  constructor(value) {
    /** @type {Options | VFile} */
    let options

    if (!value) {
      options = {}
    } else if (typeof value === 'string' || buffer(value)) {
      options = {value}
    } else if (isUrl(value)) {
      options = {path: value}
    } else {
      options = value
    }

    /**
     * Place to store custom information (default: `{}`).
     *
     * It’s OK to store custom data directly on the file but moving it to
     * `data` is recommended.
     *
     * @type {Data}
     */
    this.data = {}

    /**
     * List of messages associated with the file.
     *
     * @type {Array<VFileMessage>}
     */
    this.messages = []

    /**
     * List of filepaths the file moved between.
     *
     * The first is the original path and the last is the current path.
     *
     * @type {Array<string>}
     */
    this.history = []

    /**
     * Base of `path` (default: `process.cwd()` or `'/'` in browsers).
     *
     * @type {string}
     */
    this.cwd = proc.cwd()

    /* eslint-disable no-unused-expressions */
    /**
     * Raw value.
     *
     * @type {Value}
     */
    this.value

    // The below are non-standard, they are “well-known”.
    // As in, used in several tools.

    /**
     * Whether a file was saved to disk.
     *
     * This is used by vfile reporters.
     *
     * @type {boolean}
     */
    this.stored

    /**
     * Custom, non-string, compiled, representation.
     *
     * This is used by unified to store non-string results.
     * One example is when turning markdown into React nodes.
     *
     * @type {unknown}
     */
    this.result

    /**
     * Source map.
     *
     * This type is equivalent to the `RawSourceMap` type from the `source-map`
     * module.
     *
     * @type {Map | null | undefined}
     */
    this.map
    /* eslint-enable no-unused-expressions */

    // Set path related properties in the correct order.
    let index = -1

    while (++index < order.length) {
      const prop = order[index]

      // Note: we specifically use `in` instead of `hasOwnProperty` to accept
      // `vfile`s too.
      if (
        prop in options &&
        options[prop] !== undefined &&
        options[prop] !== null
      ) {
        // @ts-expect-error: TS doesn’t understand basic reality.
        this[prop] = prop === 'history' ? [...options[prop]] : options[prop]
      }
    }

    /** @type {string} */
    let prop

    // Set non-path related properties.
    for (prop in options) {
      // @ts-expect-error: fine to set other things.
      if (!order.includes(prop)) {
        // @ts-expect-error: fine to set other things.
        this[prop] = options[prop]
      }
    }
  }

  /**
   * Get the full path (example: `'~/index.min.js'`).
   *
   * @returns {string}
   */
  get path() {
    return this.history[this.history.length - 1]
  }

  /**
   * Set the full path (example: `'~/index.min.js'`).
   *
   * Cannot be nullified.
   * You can set a file URL (a `URL` object with a `file:` protocol) which will
   * be turned into a path with `url.fileURLToPath`.
   *
   * @param {string | URL} path
   */
  set path(path) {
    if (isUrl(path)) {
      path = urlToPath(path)
    }

    assertNonEmpty(path, 'path')

    if (this.path !== path) {
      this.history.push(path)
    }
  }

  /**
   * Get the parent path (example: `'~'`).
   */
  get dirname() {
    return typeof this.path === 'string' ? path.dirname(this.path) : undefined
  }

  /**
   * Set the parent path (example: `'~'`).
   *
   * Cannot be set if there’s no `path` yet.
   */
  set dirname(dirname) {
    assertPath(this.basename, 'dirname')
    this.path = path.join(dirname || '', this.basename)
  }

  /**
   * Get the basename (including extname) (example: `'index.min.js'`).
   */
  get basename() {
    return typeof this.path === 'string' ? path.basename(this.path) : undefined
  }

  /**
   * Set basename (including extname) (`'index.min.js'`).
   *
   * Cannot contain path separators (`'/'` on unix, macOS, and browsers, `'\'`
   * on windows).
   * Cannot be nullified (use `file.path = file.dirname` instead).
   */
  set basename(basename) {
    assertNonEmpty(basename, 'basename')
    assertPart(basename, 'basename')
    this.path = path.join(this.dirname || '', basename)
  }

  /**
   * Get the extname (including dot) (example: `'.js'`).
   */
  get extname() {
    return typeof this.path === 'string' ? path.extname(this.path) : undefined
  }

  /**
   * Set the extname (including dot) (example: `'.js'`).
   *
   * Cannot contain path separators (`'/'` on unix, macOS, and browsers, `'\'`
   * on windows).
   * Cannot be set if there’s no `path` yet.
   */
  set extname(extname) {
    assertPart(extname, 'extname')
    assertPath(this.dirname, 'extname')

    if (extname) {
      if (extname.charCodeAt(0) !== 46 /* `.` */) {
        throw new Error('`extname` must start with `.`')
      }

      if (extname.includes('.', 1)) {
        throw new Error('`extname` cannot contain multiple dots')
      }
    }

    this.path = path.join(this.dirname, this.stem + (extname || ''))
  }

  /**
   * Get the stem (basename w/o extname) (example: `'index.min'`).
   */
  get stem() {
    return typeof this.path === 'string'
      ? path.basename(this.path, this.extname)
      : undefined
  }

  /**
   * Set the stem (basename w/o extname) (example: `'index.min'`).
   *
   * Cannot contain path separators (`'/'` on unix, macOS, and browsers, `'\'`
   * on windows).
   * Cannot be nullified (use `file.path = file.dirname` instead).
   */
  set stem(stem) {
    assertNonEmpty(stem, 'stem')
    assertPart(stem, 'stem')
    this.path = path.join(this.dirname || '', stem + (this.extname || ''))
  }

  /**
   * Serialize the file.
   *
   * @param {BufferEncoding | null | undefined} [encoding='utf8']
   *   Character encoding to understand `value` as when it’s a `Buffer`
   *   (default: `'utf8'`).
   * @returns {string}
   *   Serialized file.
   */
  toString(encoding) {
    return (this.value || '').toString(encoding || undefined)
  }

  /**
   * Create a warning message associated with the file.
   *
   * Its `fatal` is set to `false` and `file` is set to the current file path.
   * Its added to `file.messages`.
   *
   * @param {string | Error | VFileMessage} reason
   *   Reason for message, uses the stack and message of the error if given.
   * @param {Node | NodeLike | Position | Point | null | undefined} [place]
   *   Place in file where the message occurred.
   * @param {string | null | undefined} [origin]
   *   Place in code where the message originates (example:
   *   `'my-package:my-rule'` or `'my-rule'`).
   * @returns {VFileMessage}
   *   Message.
   */
  message(reason, place, origin) {
    const message = new VFileMessage(reason, place, origin)

    if (this.path) {
      message.name = this.path + ':' + message.name
      message.file = this.path
    }

    message.fatal = false

    this.messages.push(message)

    return message
  }

  /**
   * Create an info message associated with the file.
   *
   * Its `fatal` is set to `null` and `file` is set to the current file path.
   * Its added to `file.messages`.
   *
   * @param {string | Error | VFileMessage} reason
   *   Reason for message, uses the stack and message of the error if given.
   * @param {Node | NodeLike | Position | Point | null | undefined} [place]
   *   Place in file where the message occurred.
   * @param {string | null | undefined} [origin]
   *   Place in code where the message originates (example:
   *   `'my-package:my-rule'` or `'my-rule'`).
   * @returns {VFileMessage}
   *   Message.
   */
  info(reason, place, origin) {
    const message = this.message(reason, place, origin)

    message.fatal = null

    return message
  }

  /**
   * Create a fatal error associated with the file.
   *
   * Its `fatal` is set to `true` and `file` is set to the current file path.
   * Its added to `file.messages`.
   *
   * > 👉 **Note**: a fatal error means that a file is no longer processable.
   *
   * @param {string | Error | VFileMessage} reason
   *   Reason for message, uses the stack and message of the error if given.
   * @param {Node | NodeLike | Position | Point | null | undefined} [place]
   *   Place in file where the message occurred.
   * @param {string | null | undefined} [origin]
   *   Place in code where the message originates (example:
   *   `'my-package:my-rule'` or `'my-rule'`).
   * @returns {never}
   *   Message.
   * @throws {VFileMessage}
   *   Message.
   */
  fail(reason, place, origin) {
    const message = this.message(reason, place, origin)

    message.fatal = true

    throw message
  }
}

/**
 * Assert that `part` is not a path (as in, does not contain `path.sep`).
 *
 * @param {string | null | undefined} part
 *   File path part.
 * @param {string} name
 *   Part name.
 * @returns {void}
 *   Nothing.
 */
function assertPart(part, name) {
  if (part && part.includes(path.sep)) {
    throw new Error(
      '`' + name + '` cannot be a path: did not expect `' + path.sep + '`'
    )
  }
}

/**
 * Assert that `part` is not empty.
 *
 * @param {string | undefined} part
 *   Thing.
 * @param {string} name
 *   Part name.
 * @returns {asserts part is string}
 *   Nothing.
 */
function assertNonEmpty(part, name) {
  if (!part) {
    throw new Error('`' + name + '` cannot be empty')
  }
}

/**
 * Assert `path` exists.
 *
 * @param {string | undefined} path
 *   Path.
 * @param {string} name
 *   Dependency name.
 * @returns {asserts path is string}
 *   Nothing.
 */
function assertPath(path, name) {
  if (!path) {
    throw new Error('Setting `' + name + '` requires `path` to be set too')
  }
}

/**
 * Assert `value` is a buffer.
 *
 * @param {unknown} value
 *   thing.
 * @returns {value is Buffer}
 *   Whether `value` is a Node.js buffer.
 */
function buffer(value) {
  return bufferLike(value)
}