/**
 * @import {Node, Point, Position} from 'unist'
 * @import {Options as MessageOptions} from 'vfile-message'
 * @import {Compatible, Data, Map, Options, Value} from 'vfile'
 */

/**
 * @typedef {object & {type: string, position?: Position | undefined}} NodeLike
 */

import {VFileMessage} from 'vfile-message'
import {minpath} from '#minpath'
import {minproc} from '#minproc'
import {urlToPath, isUrl} from '#minurl'

/**
 * 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.
 */
const order = /** @type {const} */ ([
  'history',
  'path',
  'basename',
  'stem',
  'extname',
  'dirname'
])

export class VFile {
  /**
   * Create a new virtual file.
   *
   * `options` is treated as:
   *
   * *   `string` or `Uint8Array` — `{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 (isUrl(value)) {
      options = {path: value}
    } else if (typeof value === 'string' || isUint8Array(value)) {
      options = {value}
    } else {
      options = value
    }

    /* eslint-disable no-unused-expressions */

    /**
     * Base of `path` (default: `process.cwd()` or `'/'` in browsers).
     *
     * @type {string}
     */
    // Prevent calling `cwd` (which could be expensive) if it’s not needed;
    // the empty string will be overridden in the next block.
    this.cwd = 'cwd' in options ? '' : minproc.cwd()

    /**
     * Place to store custom info (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 file paths the file moved between.
     *
     * The first is the original path and the last is the current path.
     *
     * @type {Array<string>}
     */
    this.history = []

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

    /**
     * Raw value.
     *
     * @type {Value}
     */
    this.value

    // The below are non-standard, they are “well-known”.
    // As in, used in several tools.
    /**
     * Source map.
     *
     * This type is equivalent to the `RawSourceMap` type from the `source-map`
     * module.
     *
     * @type {Map | null | undefined}
     */
    this.map

    /**
     * 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

    /**
     * Whether a file was saved to disk.
     *
     * This is used by vfile reporters.
     *
     * @type {boolean}
     */
    this.stored
    /* eslint-enable no-unused-expressions */

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

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

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

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

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

  /**
   * Get the basename (including extname) (example: `'index.min.js'`).
   *
   * @returns {string | undefined}
   *   Basename.
   */
  get basename() {
    return typeof this.path === 'string'
      ? minpath.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).
   *
   * @param {string} basename
   *   Basename.
   * @returns {undefined}
   *   Nothing.
   */
  set basename(basename) {
    assertNonEmpty(basename, 'basename')
    assertPart(basename, 'basename')
    this.path = minpath.join(this.dirname || '', basename)
  }

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

  /**
   * Set the parent path (example: `'~'`).
   *
   * Cannot be set if there’s no `path` yet.
   *
   * @param {string | undefined} dirname
   *   Dirname.
   * @returns {undefined}
   *   Nothing.
   */
  set dirname(dirname) {
    assertPath(this.basename, 'dirname')
    this.path = minpath.join(dirname || '', this.basename)
  }

  /**
   * Get the extname (including dot) (example: `'.js'`).
   *
   * @returns {string | undefined}
   *   Extname.
   */
  get extname() {
    return typeof this.path === 'string'
      ? minpath.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.
   *
   * @param {string | undefined} extname
   *   Extname.
   * @returns {undefined}
   *   Nothing.
   */
  set extname(extname) {
    assertPart(extname, 'extname')
    assertPath(this.dirname, 'extname')

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

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

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

  /**
   * Get the full path (example: `'~/index.min.js'`).
   *
   * @returns {string}
   *   Path.
   */
  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 {URL | string} path
   *   Path.
   * @returns {undefined}
   *   Nothing.
   */
  set path(path) {
    if (isUrl(path)) {
      path = urlToPath(path)
    }

    assertNonEmpty(path, 'path')

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

  /**
   * Get the stem (basename w/o extname) (example: `'index.min'`).
   *
   * @returns {string | undefined}
   *   Stem.
   */
  get stem() {
    return typeof this.path === 'string'
      ? minpath.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).
   *
   * @param {string} stem
   *   Stem.
   * @returns {undefined}
   *   Nothing.
   */
  set stem(stem) {
    assertNonEmpty(stem, 'stem')
    assertPart(stem, 'stem')
    this.path = minpath.join(this.dirname || '', stem + (this.extname || ''))
  }

  // Normal prototypal methods.
  /**
   * Create a fatal message for `reason` associated with the file.
   *
   * The `fatal` field of the message is set to `true` (error; file not usable)
   * and the `file` field is set to the current file path.
   * The message is added to the `messages` field on `file`.
   *
   * > 🪦 **Note**: also has obsolete signatures.
   *
   * @overload
   * @param {string} reason
   * @param {MessageOptions | null | undefined} [options]
   * @returns {never}
   *
   * @overload
   * @param {string} reason
   * @param {Node | NodeLike | null | undefined} parent
   * @param {string | null | undefined} [origin]
   * @returns {never}
   *
   * @overload
   * @param {string} reason
   * @param {Point | Position | null | undefined} place
   * @param {string | null | undefined} [origin]
   * @returns {never}
   *
   * @overload
   * @param {string} reason
   * @param {string | null | undefined} [origin]
   * @returns {never}
   *
   * @overload
   * @param {Error | VFileMessage} cause
   * @param {Node | NodeLike | null | undefined} parent
   * @param {string | null | undefined} [origin]
   * @returns {never}
   *
   * @overload
   * @param {Error | VFileMessage} cause
   * @param {Point | Position | null | undefined} place
   * @param {string | null | undefined} [origin]
   * @returns {never}
   *
   * @overload
   * @param {Error | VFileMessage} cause
   * @param {string | null | undefined} [origin]
   * @returns {never}
   *
   * @param {Error | VFileMessage | string} causeOrReason
   *   Reason for message, should use markdown.
   * @param {Node | NodeLike | MessageOptions | Point | Position | string | null | undefined} [optionsOrParentOrPlace]
   *   Configuration (optional).
   * @param {string | null | undefined} [origin]
   *   Place in code where the message originates (example:
   *   `'my-package:my-rule'` or `'my-rule'`).
   * @returns {never}
   *   Never.
   * @throws {VFileMessage}
   *   Message.
   */
  fail(causeOrReason, optionsOrParentOrPlace, origin) {
    // @ts-expect-error: the overloads are fine.
    const message = this.message(causeOrReason, optionsOrParentOrPlace, origin)

    message.fatal = true

    throw message
  }

  /**
   * Create an info message for `reason` associated with the file.
   *
   * The `fatal` field of the message is set to `undefined` (info; change
   * likely not needed) and the `file` field is set to the current file path.
   * The message is added to the `messages` field on `file`.
   *
   * > 🪦 **Note**: also has obsolete signatures.
   *
   * @overload
   * @param {string} reason
   * @param {MessageOptions | null | undefined} [options]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {string} reason
   * @param {Node | NodeLike | null | undefined} parent
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {string} reason
   * @param {Point | Position | null | undefined} place
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {string} reason
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {Error | VFileMessage} cause
   * @param {Node | NodeLike | null | undefined} parent
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {Error | VFileMessage} cause
   * @param {Point | Position | null | undefined} place
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {Error | VFileMessage} cause
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @param {Error | VFileMessage | string} causeOrReason
   *   Reason for message, should use markdown.
   * @param {Node | NodeLike | MessageOptions | Point | Position | string | null | undefined} [optionsOrParentOrPlace]
   *   Configuration (optional).
   * @param {string | null | undefined} [origin]
   *   Place in code where the message originates (example:
   *   `'my-package:my-rule'` or `'my-rule'`).
   * @returns {VFileMessage}
   *   Message.
   */
  info(causeOrReason, optionsOrParentOrPlace, origin) {
    // @ts-expect-error: the overloads are fine.
    const message = this.message(causeOrReason, optionsOrParentOrPlace, origin)

    message.fatal = undefined

    return message
  }

  /**
   * Create a message for `reason` associated with the file.
   *
   * The `fatal` field of the message is set to `false` (warning; change may be
   * needed) and the `file` field is set to the current file path.
   * The message is added to the `messages` field on `file`.
   *
   * > 🪦 **Note**: also has obsolete signatures.
   *
   * @overload
   * @param {string} reason
   * @param {MessageOptions | null | undefined} [options]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {string} reason
   * @param {Node | NodeLike | null | undefined} parent
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {string} reason
   * @param {Point | Position | null | undefined} place
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {string} reason
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {Error | VFileMessage} cause
   * @param {Node | NodeLike | null | undefined} parent
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {Error | VFileMessage} cause
   * @param {Point | Position | null | undefined} place
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @overload
   * @param {Error | VFileMessage} cause
   * @param {string | null | undefined} [origin]
   * @returns {VFileMessage}
   *
   * @param {Error | VFileMessage | string} causeOrReason
   *   Reason for message, should use markdown.
   * @param {Node | NodeLike | MessageOptions | Point | Position | string | null | undefined} [optionsOrParentOrPlace]
   *   Configuration (optional).
   * @param {string | null | undefined} [origin]
   *   Place in code where the message originates (example:
   *   `'my-package:my-rule'` or `'my-rule'`).
   * @returns {VFileMessage}
   *   Message.
   */
  message(causeOrReason, optionsOrParentOrPlace, origin) {
    const message = new VFileMessage(
      // @ts-expect-error: the overloads are fine.
      causeOrReason,
      optionsOrParentOrPlace,
      origin
    )

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

    message.fatal = false

    this.messages.push(message)

    return message
  }

  /**
   * Serialize the file.
   *
   * > **Note**: which encodings are supported depends on the engine.
   * > For info on Node.js, see:
   * > <https://nodejs.org/api/util.html#whatwg-supported-encodings>.
   *
   * @param {string | null | undefined} [encoding='utf8']
   *   Character encoding to understand `value` as when it’s a `Uint8Array`
   *   (default: `'utf-8'`).
   * @returns {string}
   *   Serialized file.
   */
  toString(encoding) {
    if (this.value === undefined) {
      return ''
    }

    if (typeof this.value === 'string') {
      return this.value
    }

    const decoder = new TextDecoder(encoding || undefined)
    return decoder.decode(this.value)
  }
}

/**
 * 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 {undefined}
 *   Nothing.
 */
function assertPart(part, name) {
  if (part && part.includes(minpath.sep)) {
    throw new Error(
      '`' + name + '` cannot be a path: did not expect `' + minpath.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 an `Uint8Array`.
 *
 * @param {unknown} value
 *   thing.
 * @returns {value is Uint8Array}
 *   Whether `value` is an `Uint8Array`.
 */
function isUint8Array(value) {
  return Boolean(
    value &&
      typeof value === 'object' &&
      'byteLength' in value &&
      'byteOffset' in value
  )
}