#!/usr/bin/env python3
import argparse
import sys
import time
import subprocess
from pathlib import Path

from core import BaseTranscoder

VIDEO_DEFAULTS = {
    "libx265": ["-preset", "slow", "-pix_fmt", "yuv420p10le", "-x265-params", "aq-mode=3:aq-strength=0.8:psy-rd=1.0"],
    "libaom-av1": ["-cpu-used", "4", "-row-mt", "1", "-pix_fmt", "yuv420p10le", "-aom-params", "tune=0"],
    "libvvenc": ["-preset", "slow", "-qpa", "0", "-pix_fmt", "yuv420p10le"],
}

AUDIO_DEFAULTS = {
    "fdkaac": ["-m", "4"],
    "opus": ["-c:a", "libopus", "-b:a", "128k", "-vbr", "on"],
}


class MediaTranscoder2Pass(BaseTranscoder):
    def __init__(self, args):
        super().__init__(args, VIDEO_DEFAULTS, AUDIO_DEFAULTS)
        self.target_bitrate = args.bitrate
        self.passlog_prefix = self.out_dir / f"passlog_{self.basename}_{self.vencoder}_{int(time.time())}"

    def execute(self):
        print(f"--- 初始化 2-Pass 转码任务 ---")
        self.orig_info = self.get_media_info(self.input_path)
        if not self.orig_info:
            raise ValueError("无法读取输入文件元数据。")

        start_time = time.time()
        try:
            self._run_pass_1()
            if self.aencoder == "fdkaac":
                self._run_pass_2_external_audio()
            else:
                self._run_pass_2_standard()
        except subprocess.CalledProcessError as e:
            self._cleanup()
            self._send_notification(error=f"转码失败，退出码: {e.returncode}", extra_title="2-Pass转码")
            sys.exit(f"\n转码失败，退出码: {e.returncode}")

        self._cleanup()
        encode_time = time.time() - start_time

        new_info = self.get_media_info(self.output_path)
        vmaf_score, psnr_score = "N/A", "N/A"

        if self.run_metrics and new_info:
            vmaf_score, psnr_score = self._run_vmaf_psnr(new_info)

        log_content = self._generate_log_content(
            encode_time, new_info, vmaf_score, psnr_score, extra_info=f"设定码率: {self.target_bitrate}\n"
        )

        with open(self.log_path, "a", encoding="utf-8") as f:
            f.write(log_content)

        self._send_notification(encode_time=encode_time, new_info=new_info, vmaf=vmaf_score,
                                full_text=log_content, extra_title="2-Pass转码")

        print(f"\n转码完成！耗时: {encode_time:.2f} 秒")
        print(f"输出文件: {self.output_path}")

    def _get_base_video_cmd(self, pass_num):
        cmd = ["-c:v", self.vencoder]
        if hasattr(self, 'vf_string') and self.vf_string:
            cmd.extend(["-vf", self.vf_string])
        cmd.extend([
            *self.v_params,
            "-b:v", self.target_bitrate,
            "-pass", str(pass_num),
            "-passlogfile", str(self.passlog_prefix),
        ])
        return cmd

    def _run_pass_1(self):
        print("\n[Pass 1] 正在进行第一阶段视频分析...")
        cmd = ["ffmpeg", "-y", "-i", str(self.input_path), *self._get_base_video_cmd(1), "-an", "-f", "null", "-"]
        subprocess.run(cmd, check=True)

    def _run_pass_2_external_audio(self):
        print("\n[Pass 2 - Audio] 提取音频流并使用外部 fdkaac 编码...")
        temp_wav = self.out_dir / f"temp_{self.input_path.stem}.wav"
        temp_m4a = self.out_dir / f"temp_{self.input_path.stem}.m4a"
        self.temp_files.extend([temp_wav, temp_m4a])

        subprocess.run(["ffmpeg", "-y", "-i", str(self.input_path), "-vn", "-c:a", "pcm_s16le", str(temp_wav)], check=True)
        subprocess.run(["fdkaac"] + self.a_params + [str(temp_wav), "-o", str(temp_m4a)], check=True)

        print("\n[Pass 2 - Video] 正在进行第二阶段最终编码并混流...")
        cmd = [
            "ffmpeg", "-y", "-i", str(self.input_path), "-i", str(temp_m4a),
            "-map", "0:v:0", "-map", "1:a:0",
            *self._get_base_video_cmd(2), "-c:a", "copy", str(self.output_path),
        ]
        subprocess.run(cmd, check=True)

    def _run_pass_2_standard(self):
        print("\n[Pass 2] 正在进行第二阶段最终编码 (包含音频)...")
        cmd = ["ffmpeg", "-y", "-i", str(self.input_path), *self._get_base_video_cmd(2), *self.a_params, str(self.output_path)]
        subprocess.run(cmd, check=True)

    def _cleanup(self):
        super()._cleanup()
        for log_file in self.out_dir.glob(f"{self.passlog_prefix.name}*"):
            try:
                log_file.unlink()
            except Exception as e:
                print(f"[Cleanup Warning] 无法删除临时日志 {log_file.name}: {e}")


def main():
    parser = argparse.ArgumentParser(description="2-Pass 可配置视频转码脚本")
    parser.add_argument("-i", "--input", required=True, help="输入视频文件")
    parser.add_argument("-b", "--bitrate", required=True, help="目标视频码率 (例如: 8M, 3000K)")
    parser.add_argument("-d", "--outdir", help="指定输出目录 (默认与输入文件同目录)")
    parser.add_argument("-cv", "--vencoder", choices=VIDEO_DEFAULTS.keys(), default="libx265", help="视频编码器 (默认 libx265)")
    parser.add_argument("-ca", "--aencoder", choices=AUDIO_DEFAULTS.keys(), default="opus", help="音频编码器 (默认 opus)")
    parser.add_argument("--vargs", type=str, default="", help="覆盖默认视频编码参数")
    parser.add_argument("--aargs", type=str, default="", help="覆盖默认音频编码参数")
    parser.add_argument("--fps", type=str, default="", help="指定帧率 (例如 60, 30000/1001)")
    parser.add_argument("--res", type=str, default="", help="指定分辨率，格式与scale滤镜相同 (例如 1920:1080)")
    parser.add_argument("--metrics", action=argparse.BooleanOptionalAction, default=True, help="结束后运行 VMAF/PSNR")
    parser.add_argument("--notify", choices=["none", "mail", "notify"], default="mail", help="完成后的通知方式 (默认 mail)")

    try:
        transcoder = MediaTranscoder2Pass(parser.parse_args())
        transcoder.execute()
    except Exception as e:
        sys.exit(f"发生错误: {e}")


if __name__ == "__main__":
    main()