package ffmpeg_go

import (
	"context"
	"errors"
	"io"
	"log"
	"os"
	"strings"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3/s3manager"
)

// Input file URL (ffmpeg ``-i`` option)
//
// Any supplied kwargs are passed to ffmpeg verbatim (e.g. ``t=20``,
// ``f='mp4'``, ``acodec='pcm'``, etc.).
//
// To tell ffmpeg to read from stdin, use ``pipe:`` as the filename.
//
// Official documentation: `Main options <https://ffmpeg.org/ffmpeg.html#Main-options>`__
func Input(filename string, kwargs ...KwArgs) *Stream {
	args := MergeKwArgs(kwargs)
	args["filename"] = filename
	if fmt := args.PopString("f"); fmt != "" {
		if args.HasKey("format") {
			panic(errors.New("can't specify both `format` and `f` options"))
		}
		args["format"] = fmt
	}
	return NewInputNode("input", nil, args).Stream("", "")
}

// Add extra global command-line argument(s), e.g. ``-progress``.
func (s *Stream) GlobalArgs(args ...string) *Stream {
	if s.Type != "OutputStream" {
		panic("cannot overwrite outputs on non-OutputStream")
	}
	return NewGlobalNode("global_args", []*Stream{s}, args, nil).Stream("", "")
}

// Overwrite output files without asking (ffmpeg ``-y`` option)
//
// Official documentation: `Main options <https://ffmpeg.org/ffmpeg.html#Main-options>`_
func (s *Stream) OverwriteOutput(stream *Stream) *Stream {
	if s.Type != "OutputStream" {
		panic("cannot overwrite outputs on non-OutputStream")
	}
	return NewGlobalNode("overwrite_output", []*Stream{stream}, []string{"-y"}, nil).Stream("", "")
}

// Include all given outputs in one ffmpeg command line
func MergeOutputs(streams ...*Stream) *Stream {
	return NewMergeOutputsNode("merge_output", streams).Stream("", "")
}

//Output file URL
//
//    Syntax:
//        `ffmpeg.Output([]*Stream{stream1, stream2, stream3...}, filename, kwargs)`
//
//    Any supplied keyword arguments are passed to ffmpeg verbatim (e.g.
//    ``t=20``, ``f='mp4'``, ``acodec='pcm'``, ``vcodec='rawvideo'``,
//    etc.).  Some keyword-arguments are handled specially, as shown below.
//
//    Args:
//        video_bitrate: parameter for ``-b:v``, e.g. ``video_bitrate=1000``.
//        audio_bitrate: parameter for ``-b:a``, e.g. ``audio_bitrate=200``.
//        format: alias for ``-f`` parameter, e.g. ``format='mp4'``
//            (equivalent to ``f='mp4'``).
//
//    If multiple streams are provided, they are mapped to the same
//    output.
//
//    To tell ffmpeg to write to stdout, use ``pipe:`` as the filename.
//
//    Official documentation: `Synopsis <https://ffmpeg.org/ffmpeg.html#Synopsis>`__
//    """
func Output(streams []*Stream, fileName string, kwargs ...KwArgs) *Stream {
	args := MergeKwArgs(kwargs)
	if !args.HasKey("filename") {
		if fileName == "" {
			panic("filename must be provided")
		}
		args["filename"] = fileName
	}

	return NewOutputNode("output", streams, nil, args).Stream("", "")
}

func (s *Stream) Output(fileName string, kwargs ...KwArgs) *Stream {
	if s.Type != "FilterableStream" {
		log.Panic("cannot output on non-FilterableStream")
	}
	if strings.HasPrefix(fileName, "s3://") {
		return s.outputS3Stream(fileName, kwargs...)
	}
	return Output([]*Stream{s}, fileName, kwargs...)
}

func (s *Stream) outputS3Stream(fileName string, kwargs ...KwArgs) *Stream {
	r, w := io.Pipe()
	fileL := strings.SplitN(strings.TrimPrefix(fileName, "s3://"), "/", 2)
	if len(fileL) != 2 {
		log.Panic("s3 file format not valid")
	}
	args := MergeKwArgs(kwargs)
	awsConfig := args.PopDefault("aws_config", &aws.Config{}).(*aws.Config)
	bucket, key := fileL[0], fileL[1]
	o := Output([]*Stream{s}, "pipe:", args).
		WithOutput(w, os.Stdout)
	done := make(chan struct{})
	runHook := RunHook{
		f: func() {
			defer func() {
				done <- struct{}{}
			}()

			sess, err := session.NewSession(awsConfig)
			uploader := s3manager.NewUploader(sess)
			_, err = uploader.Upload(&s3manager.UploadInput{
				Bucket: &bucket,
				Key:    &key,
				Body:   r,
			})
			//fmt.Println(ioutil.ReadAll(r))
			if err != nil {
				log.Println("upload fail", err)
			}
		},
		done:   done,
		closer: w,
	}
	o.Context = context.WithValue(o.Context, "run_hook", &runHook)
	return o
}