#!/usr/bin/env python3
"""
xconv ffpmeg wrapper based on AdvancedAV
-----------------------------------------------------------
    AdvancedAV helps with constructing FFmpeg commandline arguments.

    It can automatically parse input files with the help of FFmpeg's ffprobe tool (WiP)
    and allows programatically mapping streams to output files and setting metadata on them.
-----------------------------------------------------------
    Copyright (c) 2015-2016 Taeyeon Mori

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

from advancedav import SimpleAV, version_info as aav_version_info

from argparse import ArgumentParser, Action
from abc import ABCMeta, abstractmethod
from itertools import chain
from functools import wraps
from os.path import isdir, join as build_path, basename, splitext, exists
from os import environ

version_info = 0, 1, 1

# == Misc. helpers ==
def __update(f, name, update):
    if hasattr(f, name):
        getattr(f, name).update(update);
    else:
        setattr(f, name, update)

def __defaults(obj, **defs):
    for k, v in defs.items():
        if not hasattr(obj, k):
            setattr(obj, k, v)


# == Profile Decorators ==
profiles = {}

def profile(f):
    """
    Define a XConv Profile

    Note: Should be outermost decorator
    """
    __defaults(f,
        description=None,
        container=None,
        ext=None,
        defines={},
        features={})
    profiles[f.__name__] = f
    return f


def description(desc):
    """ Add a profile description """
    def apply(f):
        f.description = desc
        return f
    return apply


def output(container=None, ext=None):
    """ Add output file information """
    def apply(f):
        if container:
            f.container = container
            f.ext = "mkv" if container == "matroska" else container
        if ext:
            f.ext = ext
        return f
    return apply


def defines(**defs):
    """ Document supported defines with description """
    def apply(f):
        __update(f, "defines", defs)
        return f
    return apply


def features(**features):
    """ Set opaque feature flags """
    def apply(f):
        __update(f, "features", features)
        return f
    return apply


def singleaudio(profile):
    """
    Operate on a single audio stream (The first one found)

    The stream will be passed to the decorated function in the "stream" keyword
    """
    @wraps(profile)
    def wrapper(task, **kwds):
        try:
            audio_stream = next(task.iter_audio_streams())
        except StopIteration:
            print("No audio track in '%s'" % "', '".join(map(lambda x: x.name, task.inputs)))
            return False
        return profile(task, stream=audio_stream, **kwds)
    __update(wrapper, "features", {"singleaudio": None})
    return wrapper


# == Utilities for Profiles ==
def downscale(outstream, width, height):
    # Scale while keeping aspect ratio; never upscale.
    outstream.options["filter_complex"] = "scale=iw*min(1\,min(%i/iw\,%i/ih)):-1" % (width, height)


def apply_defines(defines, object, *names, **maps):
    # Apply defines to task/stream options
    maps = (maps or {})
    for name in names:
        maps[name] = name
    for define, option in maps.items():
        if define in defines:
            object.options[option] = defines[define]


def options(object, **options):
    object.options.update(options)
    return object


def change_format(outfile, format=None, ext=None):
    # Diverge from decorated format.
    # Watch out for args.genout!!
    if format:
        outfile.container = format
    if ext:
        outfile.name = splitext(outfile.name)[0] + "." + ext


# == Profile definitions ==
@profile
@description("First Video H.264 Main fastdecode animation, max 1280x800; Audio AAC; Keep subtitles")
@output(container="matroska", ext="mkv")
def laptop(task):
    # add first video stream
    for s in task.iter_video_streams():
        os = task.map_stream(s)
        options(os,
            codec="libx264",
            tune=("fastdecode", "animation"),
            profile="main",
            preset="fast")
        downscale(os, 1280, 800)
        break
    # Add all audio streams (reencode to aac if necessary)
    for s in task.iter_audio_streams():
        os = task.map_stream(s)
        if s.codec != "aac":
            os.options["codec"] = "aac"
    # add all subtitle and attachment streams
    for s in chain(task.iter_subtitle_streams(), task.iter_attachment_streams()):
        task.map_stream(s)
    # go
    return True


@profile
@description("Save the first audio track as FLAC.")
@output(ext="flac")
@singleaudio
def flac(task, stream):
    if stream.codec == "ape":
        stream.file.options["max_samples"] = "all" # Monkey's insane preset is insane.
    options(task.map_stream(stream),
        codec="flac",
        compression_level="10")
    return True


@profile
@description("Encode Opus Audio")
@output(ext="mka", container="matroska")
@defines(ogg="Use Ogg/Opus output container",
    bitrate="Target bitrate (Default 96k)")
@features(argshax=None)
@singleaudio
def opus(task, stream, defines, args):
    os = task.map_stream(stream)
    options(os,
        codec="libopus",
        vbr="on")
    # options
    apply_defines(defines, os, bitrate="b")
    # Output format
    if "ogg" in defines:
        change_format(task.output, "ogg", "opus" if args.genout else None)
    return True


@profile
@description("Encode Opus Audiobook")
@output(container="ogg", ext="ogg")
@defines(stereo="Keep stereo channels")
@singleaudio
def audiobook(task, stream, defines):
    out = task.map_stream(stream)
    options(out,
        codec="libopus",
        vbr="on",
        b="24k",
        ac="1",
        application="voip",
        frame_duration="40")
    if "stereo" in defines:
        options(out,
            ac="2",
            b="32k")
    return True


@profile
@description("Copy all streams to a new container")
@defines(format="Container format",
    fext="File extension")
@features(argshax=None)
def remux(task, defines, args):
    change_format(task.output,
        defines["format"] if "format" in defines else None,
        defines["fext"] if "fext" in defines and args.genout else None)
    all(task.map_stream(s) for s in task.iter_streams())
    return True


# == Support code ==
class ProfilesAction(Action):
    def __call__(self, parser, *a, **b):
        print("Available Profiles:")
        for name, profile in sorted(profiles.items()):
            print("  %-20s %s" % (name, profile.description if profile.description else ""))
        parser.exit()


class ProfileInfoAction(Action):
    def __call__(self, parser, args, *a, **b):
        if not args.profile:
            print("-i must come after -p")
            parser.exit() # todo
        profile = profiles[args.profile]
        print("Profile '%s':" % args.profile)
        if profile.description:
            print("  Description: %s" % profile.description)
        output_info = []
        if profile.container:
            output_info.append("Format: %s" % profile.container)
        if profile.ext:
            output_info.append("File extension: %s" % profile.ext)
        if output_info:
            print("  Output: %s" % "; ".join(output_info))
        if profile.features:
            print("  Flags: %s" % ", ".join("%s(%r)" % (k, v) if v is not None else k for k, v in profile.features.items()))
        if profile.defines:
            print("  Supported defines:")
            for define in sorted(profile.defines.items()):
                print("    %s: %s" % define)
        parser.exit()


class DefineAction(Action):
    def __init__(self, option_strings, dest, nargs=None, default=None, **kwargs):
        super().__init__(option_strings, dest, nargs=1, default=default or {}, **kwargs)
    def __call__(self, parser, namespace, values, option_string=None):
        value = values[0]
        dest = getattr(namespace, self.dest)
        if "=" in value:
            k, v = value.split("=")
            dest[k] = v
        else:
            dest[value] = True


def parse_args(argv):
    parser = ArgumentParser(prog=argv[0])
    parser.add_argument("-v", "--verbose", help="Enable verbose output", action="store_true")
    parser.add_argument("-q", "--quiet", help="Be less verbose", action="store_true")
    files = parser.add_argument_group("Files")
    files.add_argument("inputs", nargs="+", help="The input file(s)")
    files.add_argument("output", help="The output filename or directory")
    files.add_argument("-m", "--merge", help="Merge streams from all inputs instead of mapping each input to an output", action="store_true")
    files.add_argument("-u", "--update", help="Only work on files that don't already exist", action="store_true")
    profile = parser.add_argument_group("Profile")
    profile.add_argument("-p", "--profile", choices=profiles.keys(), required=True, help="Specify the profile. See the source code.")
    profile.add_argument("-l", "--list-profiles", action=ProfilesAction, nargs=0, help="List profiles and exit")
    profile.add_argument("-i", "--profile-info", action=ProfileInfoAction, nargs=0, help="Give info about a profile")
    profile.add_argument("-D", "--define", help="Define an option to be used by the profile", action=DefineAction, metavar="NAME[=VALUE]")
    progs = parser.add_argument_group("Programs")
    progs.add_argument("--ffmpeg", default="ffmpeg", help="Path to the ffmpeg executable")
    progs.add_argument("--ffprobe", default="ffprobe", help="Path to the ffprobe executable")
    return parser.parse_args(argv[1:])


def make_outfile(args, profile, infile):
    if args.genout:
        if hasattr(profile, "ext"):
            return build_path(args.output, ".".join((splitext(basename(infile))[0], profile.ext if profile.ext else "bin")))
        else:
            return build_path(args.output, basename(infile))
    else:
        return args.output


def main(argv):
    import logging

    # Parse commandline
    args = parse_args(argv)

    logging.basicConfig(level=logging.DEBUG if args.verbose else logging.INFO)

    profile = profiles[args.profile]

    args.genout = isdir(args.output)
    if not args.genout:
        if len(args.inputs) > 1:
            print("Output path '%s' is not a directory." % args.output)
            return -1

    print("\033[36mXConv %s (AdvancedAV %s) (c) Taeyeon Mori\033[0m" % (".".join(map(str, version_info)), ".".join(map(str, aav_version_info))))
    print("\033[34mProfile: %s\033[0m" % args.profile)

    # Initialize AAV
    aav = SimpleAV(ffmpeg=args.ffmpeg, ffprobe=args.ffprobe)

    if args.quiet:
        aav.global_conv_args = "-loglevel", "warning"

    # Collect Tasks
    tasks = []

    print("\033[35mCollecting Tasks..\033[0m")

    if args.merge:
        task = aav.create_job(make_outfile(args, profile, args.inputs[0]))

        for input in args.inputs:
            task.add_input(input)

        tasks.append(task)

    else:
        for input in args.inputs:
            out = make_outfile(args, profile, input)
            if args.update and exists(out):
                continue
            task = aav.create_job(out, profile.container)
            task.add_input(input)
            tasks.append(task)

            task.options["hide_banner"] = None

    print("\033[35mPreparing Tasks..\033[0m")

    # Prepare profile parameters
    pkw = {}
    if profile.defines:
        pkw["defines"] = args.define
    if profile.features:
        if "argshax" in profile.features:
            pkw["args"] = args

    # Apply profile
    for task in tasks:
        print("\033[32m  Applying profile for '%s'\033[0m" % basename(task.name), end="\033[K\r")
        res = profile(task, **pkw)
        if not res:
            print("\033[31m  Failed to apply profile for '%s'\033[0m\033[K" % basename(task.name))
            return 1

    print("\033[35mExecuting Tasks..\033[0m\033[K")

    # Commit
    for task in tasks:
        print("\033[32m  Processing '%s'\033[0m" % basename(task.name))
        task.commit()

    return 0


if __name__ == "__main__":
    import sys
    sys.exit(main(sys.argv))