import type { Form, MinimatchOptions } from 'minimatch'
import { Minimatch } from 'minimatch'
import type { Minipass } from 'minipass'
import { fileURLToPath } from 'node:url'
import type { FSOption, Path } from 'path-scurry'
import {
  PathScurry,
  PathScurryDarwin,
  PathScurryPosix,
  PathScurryWin32,
} from 'path-scurry'
import type { IgnoreLike } from './ignore.js'
import { Pattern } from './pattern.js'
import { GlobStream, GlobWalker } from './walker.js'

export type MatchSet = Minimatch['set']
export type GlobParts = Exclude<Minimatch['globParts'], undefined>

// if no process global, just call it linux.
// so we default to case-sensitive, / separators
const defaultPlatform: NodeJS.Platform =
  (
    typeof process === 'object' &&
    process &&
    typeof process.platform === 'string'
  ) ?
    process.platform
  : 'linux'

/**
 * A `GlobOptions` object may be provided to any of the exported methods, and
 * must be provided to the `Glob` constructor.
 *
 * All options are optional, boolean, and false by default, unless otherwise
 * noted.
 *
 * All resolved options are added to the Glob object as properties.
 *
 * If you are running many `glob` operations, you can pass a Glob object as the
 * `options` argument to a subsequent operation to share the previously loaded
 * cache.
 */
export interface GlobOptions {
  /**
   * Set to `true` to always receive absolute paths for
   * matched files. Set to `false` to always return relative paths.
   *
   * When this option is not set, absolute paths are returned for patterns
   * that are absolute, and otherwise paths are returned that are relative
   * to the `cwd` setting.
   *
   * This does _not_ make an extra system call to get
   * the realpath, it only does string path resolution.
   *
   * Conflicts with {@link withFileTypes}
   */
  absolute?: boolean

  /**
   * Set to false to enable {@link windowsPathsNoEscape}
   *
   * @deprecated
   */
  allowWindowsEscape?: boolean

  /**
   * The current working directory in which to search. Defaults to
   * `process.cwd()`.
   *
   * May be either a string path or a `file://` URL object or string.
   */
  cwd?: string | URL

  /**
   * Include `.dot` files in normal matches and `globstar`
   * matches. Note that an explicit dot in a portion of the pattern
   * will always match dot files.
   */
  dot?: boolean

  /**
   * Prepend all relative path strings with `./` (or `.\` on Windows).
   *
   * Without this option, returned relative paths are "bare", so instead of
   * returning `'./foo/bar'`, they are returned as `'foo/bar'`.
   *
   * Relative patterns starting with `'../'` are not prepended with `./`, even
   * if this option is set.
   */
  dotRelative?: boolean

  /**
   * Follow symlinked directories when expanding `**`
   * patterns. This can result in a lot of duplicate references in
   * the presence of cyclic links, and make performance quite bad.
   *
   * By default, a `**` in a pattern will follow 1 symbolic link if
   * it is not the first item in the pattern, or none if it is the
   * first item in the pattern, following the same behavior as Bash.
   */
  follow?: boolean

  /**
   * string or string[], or an object with `ignored` and `childrenIgnored`
   * methods.
   *
   * If a string or string[] is provided, then this is treated as a glob
   * pattern or array of glob patterns to exclude from matches. To ignore all
   * children within a directory, as well as the entry itself, append `'/**'`
   * to the ignore pattern.
   *
   * **Note** `ignore` patterns are _always_ in `dot:true` mode, regardless of
   * any other settings.
   *
   * If an object is provided that has `ignored(path)` and/or
   * `childrenIgnored(path)` methods, then these methods will be called to
   * determine whether any Path is a match or if its children should be
   * traversed, respectively.
   */
  readonly ignore?: string | string[] | IgnoreLike | ReadonlyArray<string>

  /**
   * Treat brace expansion like `{a,b}` as a "magic" pattern. Has no
   * effect if {@link nobrace} is set.
   *
   * Only has effect on the {@link hasMagic} function.
   */
  magicalBraces?: boolean

  /**
   * Add a `/` character to directory matches. Note that this requires
   * additional stat calls in some cases.
   */
  mark?: boolean

  /**
   * Perform a basename-only match if the pattern does not contain any slash
   * characters. That is, `*.js` would be treated as equivalent to
   * `**\/*.js`, matching all js files in all directories.
   */
  matchBase?: boolean

  /**
   * Limit the directory traversal to a given depth below the cwd.
   * Note that this does NOT prevent traversal to sibling folders,
   * root patterns, and so on. It only limits the maximum folder depth
   * that the walk will descend, relative to the cwd.
   */
  maxDepth?: number

  /**
   * Do not expand `{a,b}` and `{1..3}` brace sets.
   */
  nobrace?: boolean

  /**
   * Perform a case-insensitive match. This defaults to `true` on macOS and
   * Windows systems, and `false` on all others.
   *
   * **Note** `nocase` should only be explicitly set when it is
   * known that the filesystem's case sensitivity differs from the
   * platform default. If set `true` on case-sensitive file
   * systems, or `false` on case-insensitive file systems, then the
   * walk may return more or less results than expected.
   */
  nocase?: boolean

  /**
   * Do not match directories, only files. (Note: to match
   * _only_ directories, put a `/` at the end of the pattern.)
   */
  nodir?: boolean

  /**
   * Do not match "extglob" patterns such as `+(a|b)`.
   */
  noext?: boolean

  /**
   * Normalize unicode in the pattern, and in the file names that it is
   * matched against, with this form: `'NFC'`, `'NFD'`, `'NFKC'`, or
   * `'NFKD'`. `true` means `'NFC'`. This is passed to minimatch, so it
   * applies to the portions of the pattern with magic, and to the
   * `ignore` patterns.
   *
   * The portions of the pattern without magic are looked up with
   * path-scurry, which already compares the names of the entries
   * that it knows in their `'NFKD'` form.
   */
  normalize?: boolean | Form

  /**
   * Do not match `**` against multiple filenames. (Ie, treat it as a normal
   * `*` instead.)
   *
   * Conflicts with {@link matchBase}
   */
  noglobstar?: boolean

  /**
   * Defaults to value of `process.platform` if available, or `'linux'` if
   * not. Setting `platform:'win32'` on non-Windows systems may cause strange
   * behavior.
   */
  platform?: NodeJS.Platform

  /**
   * Set to true to call `fs.realpath` on all of the
   * results. In the case of an entry that cannot be resolved, the
   * entry is omitted. This incurs a slight performance penalty, of
   * course, because of the added system calls.
   */
  realpath?: boolean

  /**
   *
   * A string path resolved against the `cwd` option, which
   * is used as the starting point for absolute patterns that start
   * with `/`, (but not drive letters or UNC paths on Windows).
   *
   * Note that this _doesn't_ necessarily limit the walk to the
   * `root` directory, and doesn't affect the cwd starting point for
   * non-absolute patterns. A pattern containing `..` will still be
   * able to traverse out of the root directory, if it is not an
   * actual root directory on the filesystem, and any non-absolute
   * patterns will be matched in the `cwd`. For example, the
   * pattern `/../*` with `{root:'/some/path'}` will return all
   * files in `/some`, not all files in `/some/path`. The pattern
   * `*` with `{root:'/some/path'}` will return all the entries in
   * the cwd, not the entries in `/some/path`.
   *
   * To start absolute and non-absolute patterns in the same
   * path, you can use `{root:''}`. However, be aware that on
   * Windows systems, a pattern like `x:/*` or `//host/share/*` will
   * _always_ start in the `x:/` or `//host/share` directory,
   * regardless of the `root` setting.
   */
  root?: string

  /**
   * A [PathScurry](http://npm.im/path-scurry) object used
   * to traverse the file system. If the `nocase` option is set
   * explicitly, then any provided `scurry` object must match this
   * setting.
   */
  scurry?: PathScurry

  /**
   * Call `lstat()` on all entries, whether required or not to determine
   * if it's a valid match. When used with {@link withFileTypes}, this means
   * that matches will include data such as modified time, permissions, and
   * so on.  Note that this will incur a performance cost due to the added
   * system calls.
   */
  stat?: boolean

  /**
   * An AbortSignal which will cancel the Glob walk when
   * triggered.
   */
  signal?: AbortSignal

  /**
   * Use `\\` as a path separator _only_, and
   *  _never_ as an escape character. If set, all `\\` characters are
   *  replaced with `/` in the pattern.
   *
   *  Note that this makes it **impossible** to match against paths
   *  containing literal glob pattern characters, but allows matching
   *  with patterns constructed using `path.join()` and
   *  `path.resolve()` on Windows platforms, mimicking the (buggy!)
   *  behavior of Glob v7 and before on Windows. Please use with
   *  caution, and be mindful of [the caveat below about Windows
   *  paths](#windows). (For legacy reasons, this is also set if
   *  `allowWindowsEscape` is set to the exact value `false`.)
   */
  windowsPathsNoEscape?: boolean

  /**
   * Return [PathScurry](http://npm.im/path-scurry)
   * `Path` objects instead of strings. These are similar to a
   * NodeJS `Dirent` object, but with additional methods and
   * properties.
   *
   * Conflicts with {@link absolute}
   */
  withFileTypes?: boolean

  /**
   * An fs implementation to override some or all of the defaults.  See
   * http://npm.im/path-scurry for details about what can be overridden.
   */
  fs?: FSOption

  /**
   * Return `/` delimited paths, even on Windows.
   *
   * On posix systems, this has no effect.  But, on Windows, it means that
   * paths will be `/` delimited, and absolute paths will be their full
   * resolved UNC forms, eg instead of `'C:\\foo\\bar'`, it would return
   * `'//?/C:/foo/bar'`
   */
  posix?: boolean

  /**
   * Do not match any children of any matches. For example, the pattern
   * `**\/foo` would match `a/foo`, but not `a/foo/b/foo` in this mode.
   *
   * This is especially useful for cases like "find all `node_modules`
   * folders, but not the ones in `node_modules`".
   *
   * In order to support this, the `Ignore` implementation must support an
   * `add(pattern: string)` method. If using the default `Ignore` class, then
   * this is fine, but if this is set to `false`, and a custom `Ignore` is
   * provided that does not have an `add()` method, then it will throw an
   * error.
   *
   * **Caveat** It *only* ignores matches that would be a descendant of a
   * previous match, and only if that descendant is matched *after* the
   * ancestor is encountered. Since the file system walk happens in
   * indeterminate order, it's possible that a match will already be added
   * before its ancestor, if multiple or braced patterns are used.
   *
   * For example:
   *
   * ```ts
   * const results = await glob([
   *   // likely to match first, since it's just a stat
   *   'a/b/c/d/e/f',
   *
   *   // this pattern is more complicated! It must to various readdir()
   *   // calls and test the results against a regular expression, and that
   *   // is certainly going to take a little bit longer.
   *   //
   *   // So, later on, it encounters a match at 'a/b/c/d/e', but it's too
   *   // late to ignore a/b/c/d/e/f, because it's already been emitted.
   *   'a/[bdf]/?/[a-z]/*',
   * ], { includeChildMatches: false })
   * ```
   *
   * It's best to only set this to `false` if you can be reasonably sure that
   * no components of the pattern will potentially match one another's file
   * system descendants, or if the occasional included child entry will not
   * cause problems.
   *
   * @default true
   */
  includeChildMatches?: boolean

  /**
   * max number of `{...}` patterns to expand. Default `1_000`.
   *
   * Note: this is much less than minimatch's default of `100_000`,
   * because Glob has higher memory requirements due to walking
   * the file system tree.
   */
  braceExpandMax?: number
}

export type GlobOptionsWithFileTypesTrue = GlobOptions & {
  withFileTypes: true
  // string options not relevant if returning Path objects.
  absolute?: undefined
  mark?: undefined
  posix?: undefined
}

export type GlobOptionsWithFileTypesFalse = GlobOptions & {
  withFileTypes?: false
}

export type GlobOptionsWithFileTypesUnset = GlobOptions & {
  withFileTypes?: undefined
}

export type Result<Opts> =
  Opts extends GlobOptionsWithFileTypesTrue ? Path
  : Opts extends GlobOptionsWithFileTypesFalse ? string
  : Opts extends GlobOptionsWithFileTypesUnset ? string
  : string | Path
export type Results<Opts> = Result<Opts>[]

export type FileTypes<Opts> =
  Opts extends GlobOptionsWithFileTypesTrue ? true
  : Opts extends GlobOptionsWithFileTypesFalse ? false
  : Opts extends GlobOptionsWithFileTypesUnset ? false
  : boolean

/**
 * An object that can perform glob pattern traversals.
 */
export class Glob<Opts extends GlobOptions> implements GlobOptions {
  absolute?: boolean
  cwd: string
  root?: string
  dot: boolean
  dotRelative: boolean
  follow: boolean
  ignore?: string | string[] | IgnoreLike | ReadonlyArray<string>
  magicalBraces: boolean
  mark?: boolean
  matchBase: boolean
  maxDepth: number
  nobrace: boolean
  nocase: boolean
  nodir: boolean
  noext: boolean
  noglobstar: boolean
  pattern: string[] | ReadonlyArray<string>
  platform: NodeJS.Platform
  realpath: boolean
  scurry: PathScurry
  stat: boolean
  signal?: AbortSignal
  windowsPathsNoEscape: boolean
  withFileTypes: FileTypes<Opts>
  includeChildMatches: boolean

  /**
   * The options provided to the constructor.
   */
  opts: Opts

  /**
   * An array of parsed immutable {@link Pattern} objects.
   */
  patterns: Pattern[]

  /**
   * All options are stored as properties on the `Glob` object.
   *
   * See {@link GlobOptions} for full options descriptions.
   *
   * Note that a previous `Glob` object can be passed as the
   * `GlobOptions` to another `Glob` instantiation to re-use settings
   * and caches with a new pattern.
   *
   * Traversal functions can be called multiple times to run the walk
   * again.
   */
  constructor(pattern: string | string[], opts: Opts) {
    /* c8 ignore start */
    if (!opts) throw new TypeError('glob options required')
    /* c8 ignore stop */
    this.withFileTypes = !!opts.withFileTypes as FileTypes<Opts>
    this.signal = opts.signal
    this.follow = !!opts.follow
    this.dot = !!opts.dot
    this.dotRelative = !!opts.dotRelative
    this.nodir = !!opts.nodir
    this.mark = !!opts.mark
    if (!opts.cwd) {
      this.cwd = ''
    } else if (opts.cwd instanceof URL || opts.cwd.startsWith('file://')) {
      opts.cwd = fileURLToPath(opts.cwd)
    }
    this.cwd = opts.cwd || ''
    this.root = opts.root
    this.magicalBraces = !!opts.magicalBraces
    this.nobrace = !!opts.nobrace
    this.noext = !!opts.noext
    this.realpath = !!opts.realpath
    this.absolute = opts.absolute
    this.includeChildMatches = opts.includeChildMatches !== false

    this.noglobstar = !!opts.noglobstar
    this.matchBase = !!opts.matchBase
    this.maxDepth =
      typeof opts.maxDepth === 'number' ? opts.maxDepth : Infinity
    this.stat = !!opts.stat
    this.ignore = opts.ignore

    if (this.withFileTypes && this.absolute !== undefined) {
      throw new Error('cannot set absolute and withFileTypes:true')
    }

    let p: string[] = typeof pattern === 'string' ? [pattern] : pattern

    this.windowsPathsNoEscape =
      !!opts.windowsPathsNoEscape ||
      (opts as { allowWindowsEscape?: boolean }).allowWindowsEscape ===
        false

    if (this.windowsPathsNoEscape) {
      p = p.map(p => p.replace(/\\/g, '/'))
    }

    if (this.matchBase) {
      if (opts.noglobstar) {
        throw new TypeError('base matching requires globstar')
      }
      p = p.map(p => (p.includes('/') ? p : `./**/${p}`))
    }

    this.pattern = p

    this.platform = opts.platform || defaultPlatform
    this.opts = { ...opts, platform: this.platform }
    if (opts.scurry) {
      this.scurry = opts.scurry
      if (
        opts.nocase !== undefined &&
        opts.nocase !== opts.scurry.nocase
      ) {
        throw new Error('nocase option contradicts provided scurry option')
      }
    } else {
      const Scurry =
        opts.platform === 'win32' ? PathScurryWin32
        : opts.platform === 'darwin' ? PathScurryDarwin
        : opts.platform ? PathScurryPosix
        : PathScurry
      this.scurry = new Scurry(this.cwd, {
        nocase: opts.nocase,
        fs: opts.fs,
      })
    }
    this.nocase = this.scurry.nocase

    // If you do nocase:true on a case-sensitive file system, then
    // we need to use regexps instead of strings for non-magic
    // path portions, because statting `aBc` won't return results
    // for the file `AbC` for example.
    const nocaseMagicOnly =
      this.platform === 'darwin' || this.platform === 'win32'

    const mmo: MinimatchOptions = {
      braceExpandMax: 10_000,
      ...opts,
      dot: this.dot,
      matchBase: this.matchBase,
      nobrace: this.nobrace,
      // default nocase based on platform
      nocase: this.nocase,
      nocaseMagicOnly,
      nocomment: true,
      noext: this.noext,
      nonegate: true,
      optimizationLevel: 2,
      platform: this.platform,
      windowsPathsNoEscape: this.windowsPathsNoEscape,
    }

    const mms = this.pattern.map(p => new Minimatch(p, mmo))
    const [matchSet, globParts] = mms.reduce(
      (set: [MatchSet, GlobParts], m) => {
        set[0].push(...m.set)
        set[1].push(...m.globParts)
        return set
      },
      [[], []],
    )
    this.patterns = matchSet.map((set, i) => {
      const g = globParts[i]
      /* c8 ignore start */
      if (!g) throw new Error('invalid pattern object')
      /* c8 ignore stop */
      return new Pattern(set, g, 0, this.platform)
    })
  }

  /**
   * Returns a Promise that resolves to the results array.
   */
  async walk(): Promise<Results<Opts>>
  async walk(): Promise<(string | Path)[]> {
    // Walkers always return array of Path objects, so we just have to
    // coerce them into the right shape.  It will have already called
    // realpath() if the option was set to do so, so we know that's cached.
    // start out knowing the cwd, at least
    return await new GlobWalker(this.patterns, this.scurry.cwd, {
      ...this.opts,
      maxDepth:
        this.maxDepth !== Infinity ?
          this.maxDepth + this.scurry.cwd.depth()
        : Infinity,
      platform: this.platform,
      nocase: this.nocase,
      includeChildMatches: this.includeChildMatches,
    }).walk()
  }

  /**
   * synchronous {@link Glob.walk}
   */
  walkSync(): Results<Opts>
  walkSync(): (string | Path)[] {
    return new GlobWalker(this.patterns, this.scurry.cwd, {
      ...this.opts,
      maxDepth:
        this.maxDepth !== Infinity ?
          this.maxDepth + this.scurry.cwd.depth()
        : Infinity,
      platform: this.platform,
      nocase: this.nocase,
      includeChildMatches: this.includeChildMatches,
    }).walkSync()
  }

  /**
   * Stream results asynchronously.
   */
  stream(): Minipass<Result<Opts>, Result<Opts>>
  stream(): Minipass<string | Path, string | Path> {
    return new GlobStream(this.patterns, this.scurry.cwd, {
      ...this.opts,
      maxDepth:
        this.maxDepth !== Infinity ?
          this.maxDepth + this.scurry.cwd.depth()
        : Infinity,
      platform: this.platform,
      nocase: this.nocase,
      includeChildMatches: this.includeChildMatches,
    }).stream()
  }

  /**
   * Stream results synchronously.
   */
  streamSync(): Minipass<Result<Opts>, Result<Opts>>
  streamSync(): Minipass<string | Path, string | Path> {
    return new GlobStream(this.patterns, this.scurry.cwd, {
      ...this.opts,
      maxDepth:
        this.maxDepth !== Infinity ?
          this.maxDepth + this.scurry.cwd.depth()
        : Infinity,
      platform: this.platform,
      nocase: this.nocase,
      includeChildMatches: this.includeChildMatches,
    }).streamSync()
  }

  /**
   * Default sync iteration function. Returns a Generator that
   * iterates over the results.
   */
  iterateSync(): Generator<Result<Opts>, void, void> {
    return this.streamSync()[Symbol.iterator]()
  }
  [Symbol.iterator]() {
    return this.iterateSync()
  }

  /**
   * Default async iteration function. Returns an AsyncGenerator that
   * iterates over the results.
   */
  iterate(): AsyncGenerator<Result<Opts>, void, void> {
    return this.stream()[Symbol.asyncIterator]()
  }
  [Symbol.asyncIterator]() {
    return this.iterate()
  }
}