<?php

namespace Danjones\FFMpeg;

use FFMpeg\Format\AudioInterface;
use FFMpeg\Format\FormatInterface;
use FFMpeg\Format\ProgressListener\AbstractProgressListener;
use FFMpeg\Format\ProgressableInterface;
use FFMpeg\Format\VideoInterface;

class Stream
{
    use Traits\HasMetadata;

    protected Map $map;
    protected FormatInterface $codec;
    protected string $input = '0:0';
    protected array $flags = [];

    public function __construct(Map $map)
    {
        $this->map = $map;
    }

    public function setInput(string $input): static
    {
        $this->input = $input;

        return $this;
    }

    public function addFlag(string $key, string $value): static
    {
        $this->flags[$key] = $value;

        return $this;
    }

    public function setCodec(FormatInterface $codec): static
    {
        $this->codec = $codec;

        return $this;
    }

    // @todo add hlper methods for setting codec

    public function getCodec(): FormatInterface
    {
        return $this->codec;
    }

    public function editCodec(callable $callback): static
    {
        $callback($this->codec);

        return $this;
    }

    protected function parseCodec(): static
    {
        if ($this->codec instanceof VideoInterface) {
            return $this->parseVideo();
        }

        if ($this->codec instanceof AudioInterface) {
            return $this->parseAudio();
        }

        if ($this->codec instanceof Format\SubtitleInterface) {
            return $this->parseSubtitle();
        }

        $this->addFlag('c', 'copy');
        $this->parseExtras($this->codec->getExtraParameters());

        return $this;
    }

    protected function parseSubtitle(): static
    {
        if (null !== ($codec = $this->codec->getSubtitleCodec())) {
            $this->addFlag('c', $codec);
        }
        $this->parseExtras($this->codec->getExtraParameters());

        return $this;
    }

    protected function parseAudio(): static
    {
        if (null !== ($codec = $this->codec->getAudioCodec())) {
            $this->addFlag('c', $codec);
        }

        if (null !== ($kb = $this->codec->getAudioKiloBitrate())) {
            $this->addFlag('b', "{$kb}k");
        }

        if (null !== ($channels = $this->codec->getAudioChannels())) {
            $this->addFlag('ac', $channels);
        }
        $this->parseExtras($this->codec->getExtraParameters());

        return $this;
    }

    protected function parseVideo(): static
    {
        if (null !== ($codec = $this->codec->getVideoCodec())) {
            $this->addFlag('c', $codec);
        }

        if (0 !== ($kb = $this->codec->getKiloBitrate())) {
            $this->addFlag('b', "{$kb}k");
        }

        // If the user passed some additional format parameters.
        $this->parseExtras($this->codec->getAdditionalParameters());
        $this->parseExtras($this->codec->getExtraParameters());

        return $this;
    }

    protected function parseExtras (?array $params): void
    {
        if (is_null($params)) {
            return;
        }

        reset($params);
        while(null !== key($params)) {
            $key = current($params);
            $value = next($params);
            if (null == key($params)) {
                continue;
            }

            $this->addFlag(ltrim($key, '-k'), $value);
        }
    }

    public function saveStream(): Map
    {
        $this->map->saveStream($this);

        return $this->map;
    }

    public function buildCommand(int $idx = 0): array
    {
        $this->parseCodec();

        $commands = [];

        $commands[] = '-map';
        $commands[] = $this->input;

        foreach ($this->flags as $k => $v) {
            array_push($commands, "-{$k}:{$idx}", $v);
        }

        foreach ($this->metadata as $k => $v) {
            array_push($commands, "-metadata:s:{$idx}", "{$k}={$v}");
        }

        return $commands;
    }
}