// Type definitions for Gulp v4.0.x
// Project: http://gulpjs.com
// Definitions by: Drew Noakes <https://drewnoakes.com>, Juan Arroyave <http://jarroyave.co>
// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped

/// <reference types="node" />
/// <reference types="orchestrator" />
/// <reference types="vinyl" />


import Orchestrator = require("orchestrator");
import VinylFile = require("vinyl");

declare type Strings = string|string[];

declare namespace gulp {
    interface Gulp extends Orchestrator {
        /**
         * Define a task
         * @param name The name of the task.
         * @param deps An array of task names to be executed and completed before your task will run.
         * @param fn The function that performs the task's operations. For asynchronous tasks, you need to provide a hint when the task is complete:
         * <ul>
         *     <li>Take in a callback</li>
         *     <li>Return a stream or a promise</li>
         * </ul>
         */
        task: Orchestrator.AddMethod;
        /**
         * Takes a number of task names or functions and returns a function of the composed tasks or functions
         * When the returned function is executed, the tasks or functions will be executed in series,
         * each waiting for the prior to finish. If an error occurs, execution will stop.
         * @param A task name, a function or an array of either.
         * <ul>
         *     <li>Take in a callback</li>
         *     <li>Return a stream or a promise</li>
         * </ul>
         */
        series: SeriesMethod;
        /**
         * Takes a number of task names or functions and returns a function of the composed tasks or functions
         * When the returned function is executed, the tasks or functions will be executed in parallel,
         * all being executed at the same time. If an error occurs, all execution will complete.
         * @param A task name, a function or an array of either.
         * <ul>
         *     <li>Take in a callback</li>
         *     <li>Return a stream or a promise</li>
         * </ul>
         */
        parallel: ParallelMethod;
        /**
         * Emits files matching provided glob or an array of globs. Returns a stream of Vinyl files that can be piped to plugins.
         * @param glob Glob or array of globs to read.
         * @param opt Options to pass to node-glob through glob-stream.
         */
        src: SrcMethod;
        /**
         * Can be piped to and it will write files. Re-emits all data passed to it so you can pipe to multiple folders.
         * Folders that don't exist will be created.
         *
         * @param outFolder The path (output folder) to write files to. Or a function that returns it, the function will be provided a vinyl File instance.
         * @param opt
         */
        dest: DestMethod;
        /**
         * Watch files and do something when a file changes. This always returns an EventEmitter that emits change events.
         *
         * @param glob a single glob or array of globs that indicate which files to watch for changes.
         * @param opt options, that are passed to the gaze library.
         * @param fn a callback or array of callbacks to be called on each change, or names of task(s) to run when a file changes, added with task().
         */
        watch: WatchMethod;
    }

    interface GulpPlugin {
        (...args: any[]): NodeJS.ReadWriteStream;
    }

    interface WatchMethod {
        /**
         * Watch files and do something when a file changes. This always returns an EventEmitter that emits change events.
         *
         * @param glob a single glob or array of globs that indicate which files to watch for changes.
         * @param fn a callback or array of callbacks to be called on each change, or names of task(s) to run when a file changes, added with task().
         */
        (glob: string|string[], fn: (WatchCallback|string)): NodeJS.EventEmitter;
        /**
         * Watch files and do something when a file changes. This always returns an EventEmitter that emits change events.
         *
         * @param glob a single glob or array of globs that indicate which files to watch for changes.
         * @param fn a callback or array of callbacks to be called on each change, or names of task(s) to run when a file changes, added with task().
         */
        (glob: string|string[], fn: (WatchCallback|string)[]): NodeJS.EventEmitter;
        /**
         * Watch files and do something when a file changes. This always returns an EventEmitter that emits change events.
         *
         * @param glob a single glob or array of globs that indicate which files to watch for changes.
         * @param opt options, that are passed to the gaze library.
         * @param fn a callback or array of callbacks to be called on each change, or names of task(s) to run when a file changes, added with task().
         */
        (glob: string|string[], opt: WatchOptions, fn: (WatchCallback|string)): NodeJS.EventEmitter;
        /**
         * Watch files and do something when a file changes. This always returns an EventEmitter that emits change events.
         *
         * @param glob a single glob or array of globs that indicate which files to watch for changes.
         * @param opt options, that are passed to the gaze library.
         * @param fn a callback or array of callbacks to be called on each change, or names of task(s) to run when a file changes, added with task().
         */
        (glob: string|string[], opt: WatchOptions, fn: (WatchCallback|string)[]): NodeJS.EventEmitter;

    }

    interface DestMethod {
        /**
         * Can be piped to and it will write files. Re-emits all data passed to it so you can pipe to multiple folders.
         * Folders that don't exist will be created.
         *
         * @param outFolder The path (output folder) to write files to. Or a function that returns it, the function will be provided a vinyl File instance.
         * @param opt
         */
        (outFolder: string|((file: VinylFile) => string), opt?: DestOptions): NodeJS.ReadWriteStream;
    }

    interface SrcMethod {
        /**
         * Emits files matching provided glob or an array of globs. Returns a stream of Vinyl files that can be piped to plugins.
         * @param glob Glob or array of globs to read.
         * @param opt Options to pass to node-glob through glob-stream.
         */
        (glob: string|string[], opt?: SrcOptions): NodeJS.ReadWriteStream;
    }
    interface SeriesMethod {
        /**
         * Takes a number of task names or functions and returns a function of the composed tasks or functions.
         * When using task names, the task should already be registered.
         * When the returned function is executed, the tasks or functions will be executed in series,
         * each waiting for the prior to finish. If an error occurs, execution will stop.
         * @param tasks, string, function or array of both.
         */
        (...tasks: string[]): NodeJS.EventEmitter;

        (...tasks: Function[]): NodeJS.EventEmitter;

        (task: string|string[], ...fn: Function[]): NodeJS.EventEmitter;

        //TODO: TypeScript cannot express varargs followed by callback as a last argument...
        (task1: Strings, task2: Strings, cb?: (error?: any) => any): Function;
        (task1: Strings, task2: Strings, task3: Strings, cb?: (error?: any) => any): NodeJS.EventEmitter;
        (task1: Strings, task2: Strings, task3: Strings, task4: Strings, cb?: (error?: any) => any): NodeJS.EventEmitter;
        (task1: Strings, task2: Strings, task3: Strings, task4: Strings, task5: Strings, cb?: (error?: any) => any): NodeJS.EventEmitter;
        (task1: Strings, task2: Strings, task3: Strings, task4: Strings, task5: Strings, task6: Strings, cb?: (error?: any) => any): NodeJS.EventEmitter;

    }

    interface ParallelMethod {
        /**
         * Takes a number of task names or functions and returns a function of the composed tasks or functions.
         * When using task names, the task should already be registered.
         * When the returned function is executed, the tasks or functions will be executed in parallel,
         * all being executed at the same time. If an error occurs, all execution will complete.
         * @param tasks, string, function or array of both.
         */
        (...tasks: string[]): NodeJS.EventEmitter;

        (...tasks: Function[]): NodeJS.EventEmitter;

        (task: string|string[], ...fn: Function[]): NodeJS.EventEmitter;

        //TODO: TypeScript cannot express varargs followed by callback as a last argument...
        (task1: Strings, task2: Strings, cb?: (error?: any) => any): Function;
        (task1: Strings, task2: Strings, task3: Strings, cb?: (error?: any) => any): NodeJS.EventEmitter;
        (task1: Strings, task2: Strings, task3: Strings, task4: Strings, cb?: (error?: any) => any): NodeJS.EventEmitter;
        (task1: Strings, task2: Strings, task3: Strings, task4: Strings, task5: Strings, cb?: (error?: any) => any): NodeJS.EventEmitter;
        (task1: Strings, task2: Strings, task3: Strings, task4: Strings, task5: Strings, task6: Strings, cb?: (error?: any) => any): NodeJS.EventEmitter;

    }

    /**
     * Options to pass to node-glob through glob-stream.
     * Specifies two options in addition to those used by node-glob:
     * https://github.com/isaacs/node-glob#options
     */
    interface SrcOptions {
        /**
         * Setting this to <code>false</code> will return <code>file.contents</code> as <code>null</code>
         * and not read the file at all.
         * Default: <code>true</code>.
         */
        read?: boolean;

        /**
         * Setting this to false will return <code>file.contents</code> as a stream and not buffer files.
         * This is useful when working with large files.
         * Note: Plugins might not implement support for streams.
         * Default: <code>true</code>.
         */
        buffer?: boolean;

        /**
         * The base path of a glob.
         *
         * Default is everything before a glob starts.
         */
        base?: string;

        /**
         * The current working directory in which to search.
         * Defaults to process.cwd().
         */
        cwd?: string;

        /**
         * The place where patterns starting with / will be mounted onto.
         * Defaults to path.resolve(options.cwd, "/") (/ on Unix systems, and C:\ or some such on Windows.)
         */
        root?: string;

        /**
         * 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;

        /**
         * Set to match only fles, not directories. Set this flag to prevent copying empty directories
         */
        nodir?: boolean;

        /**
         * By default, a pattern starting with a forward-slash will be "mounted" onto the root setting, so that a valid
         * filesystem path is returned. Set this flag to disable that behavior.
         */
        nomount?: boolean;

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

        /**
         * Don't sort the results.
         */
        nosort?: boolean;

        /**
         * Set to true to stat all results. This reduces performance somewhat, and is completely unnecessary, unless
         * readdir is presumed to be an untrustworthy indicator of file existence. It will cause ELOOP to be triggered one
         * level sooner in the case of cyclical symbolic links.
         */
        stat?: boolean;

        /**
         * When an unusual error is encountered when attempting to read a directory, a warning will be printed to stderr.
         * Set the silent option to true to suppress these warnings.
         */
        silent?: boolean;

        /**
         * When an unusual error is encountered when attempting to read a directory, the process will just continue on in
         * search of other matches. Set the strict option to raise an error in these cases.
         */
        strict?: boolean;

        /**
         * See cache property above. Pass in a previously generated cache object to save some fs calls.
         */
        cache?: boolean;

        /**
         * A cache of results of filesystem information, to prevent unnecessary stat calls.
         * While it should not normally be necessary to set this, you may pass the statCache from one glob() call to the
         * options object of another, if you know that the filesystem will not change between calls.
         */
        statCache?: boolean;

        /**
         * Perform a synchronous glob search.
         */
        sync?: boolean;

        /**
         * In some cases, brace-expanded patterns can result in the same file showing up multiple times in the result set.
         * By default, this implementation prevents duplicates in the result set. Set this flag to disable that behavior.
         */
        nounique?: boolean;

        /**
         * Set to never return an empty set, instead returning a set containing the pattern itself.
         * This is the default in glob(3).
         */
        nonull?: boolean;

        /**
         * Perform a case-insensitive match. Note that case-insensitive filesystems will sometimes result in glob returning
         * results that are case-insensitively matched anyway, since readdir and stat will not raise an error.
         */
        nocase?: boolean;

        /**
         * Set to enable debug logging in minimatch and glob.
         */
        debug?: boolean;

        /**
         * Set to enable debug logging in glob, but not minimatch.
         */
        globDebug?: boolean;
    }

    interface DestOptions {
        /**
         * The output folder. Only has an effect if provided output folder is relative.
         * Default: process.cwd()
         */
        cwd?: string;

        /**
         * Octal permission string specifying mode for any folders that need to be created for output folder.
         * Default: 0777.
         */
        mode?: string;
    }

    /**
     * Options that are passed to <code>gaze</code>.
     * https://github.com/shama/gaze
     */
    interface WatchOptions {
        /** Interval to pass to fs.watchFile. */
        interval?: number;
        /** Delay for events called in succession for the same file/event. */
        debounceDelay?: number;
        /** Force the watch mode. Either 'auto' (default), 'watch' (force native events), or 'poll' (force stat polling). */
        mode?: string;
        /** The current working directory to base file patterns from. Default is process.cwd().. */
        cwd?: string;
    }

    interface WatchEvent {
        /** The type of change that occurred, either added, changed or deleted. */
        type: string;
        /** The path to the file that triggered the event. */
        path: string;
    }

    /**
     * Callback to be called on each watched file change.
     */
    interface WatchCallback {
        (event: WatchEvent): void;
    }

    interface TaskCallback {
        /**
         * Defines a task.
         * Tasks may be made asynchronous if they are passing a callback or return a promise or a stream.
         * @param cb callback used to signal asynchronous completion. Caller includes <code>err</code> in case of error.
         */
        (cb?: (err?: any) => void): any;
    }
}

declare var gulp: gulp.Gulp;

export = gulp;