#!/usr/bin/env python3
import argparse
import json
import shutil
import subprocess
from pathlib import Path

from core.config_helper import load_config_xml

# =============================
# AUDIO BUCKET LOGIC
# =============================
def choose_audio_bitrate(channels: int, bitrate_kbps: int, audio_config: dict) -> int:
    if channels == 2:
        if bitrate_kbps < 80:
            return audio_config["stereo"]["low"]
        elif bitrate_kbps < 112:
            return audio_config["stereo"]["medium"]
        else:
            return audio_config["stereo"]["high"]
    else:
        if bitrate_kbps < 176:
            return audio_config["multi_channel"]["low"]
        else:
            return audio_config["multi_channel"]["high"]

# =============================
# AUDIO STREAM DETECTION
# =============================
def get_audio_streams(input_file: Path):
    cmd = [
        "ffprobe", "-v", "error",
        "-select_streams", "a",
        "-show_entries", "stream=index,channels,bit_rate",
        "-of", "json",
        str(input_file)
    ]
    result = subprocess.run(cmd, capture_output=True, text=True)
    data = json.loads(result.stdout)
    streams = []
    for s in data.get("streams", []):
        index = s["index"]
        channels = s.get("channels", 2)
        bitrate = int(int(s.get("bit_rate", 128000)) / 1000)
        streams.append((index, channels, bitrate))
    return streams

# =============================
# FFmpeg ENCODE
# =============================
def run_ffmpeg(input_file: Path, output_file: Path, cq: int, scale_width: int, scale_height: int,
               filter_flags: str, audio_config: dict, encode_config: dict):
    streams = get_audio_streams(input_file)

    print("\n🧩 ENCODE SETTINGS")
    print(f" • Resolution: {scale_width}x{scale_height}")
    print(f" • Scale Filter: {filter_flags}")
    print(f" • CQ: {cq}")
    print(f" • Video Encoder: av1_nvenc (preset p1, pix_fmt p010le)")

    print(" • Audio Streams:")
    for (index, channels, bitrate) in streams:
        br = choose_audio_bitrate(channels, bitrate, audio_config)
        print(f"    - Stream #{index}: {channels}ch, orig≈{bitrate}kbps → target {br/1000:.1f}kbps")

    # Build CQ encode command
    cmd = [
        "ffmpeg", "-y", "-i", str(input_file),
        "-vf", f"scale={scale_width}:{scale_height}:flags={filter_flags}:force_original_aspect_ratio=decrease",
        "-map", "0:v", "-map", "0:a", "-map", "0:s?",
        "-c:v", "av1_nvenc", "-preset", "p1", "-cq", str(cq), "-pix_fmt", "p010le"
    ]
    for i, (index, channels, bitrate) in enumerate(streams):
        br = choose_audio_bitrate(channels, bitrate, audio_config)
        cmd += [f"-c:a:{i}", "aac", f"-b:a:{i}", str(br), f"-ac:{i}", str(channels)]

    cmd += ["-c:s", "copy", str(output_file)]
    subprocess.run(cmd, check=True)

    # Check size reduction
    orig_size = input_file.stat().st_size
    out_size = output_file.stat().st_size
    reduction_ratio = out_size / orig_size
    print(f"📦 Original: {orig_size/1e6:.2f} MB → Encoded: {out_size/1e6:.2f} MB ({reduction_ratio:.1%} of original)")

    # Fallback if too large
    if reduction_ratio >= 0.5:
        print(f"⚠️  Size reduction insufficient ({reduction_ratio:.0%}). Retrying with bitrate-based encode...")
        output_file.unlink(missing_ok=True)

        if scale_height >= 1080:
            vb, maxrate, bufsize = encode_config["fallback"]["bitrate_1080"], encode_config["fallback"]["maxrate_1080"], encode_config["fallback"]["bufsize_1080"]
        else:
            vb, maxrate, bufsize = encode_config["fallback"]["bitrate_720"], encode_config["fallback"]["maxrate_720"], encode_config["fallback"]["bufsize_720"]

        cmd = [
            "ffmpeg", "-y", "-i", str(input_file),
            "-vf", f"scale={scale_width}:{scale_height}:flags={filter_flags}:force_original_aspect_ratio=decrease",
            "-map", "0:v", "-map", "0:a", "-map", "0:s?",
            "-c:v", "av1_nvenc", "-preset", "p1",
            "-b:v", vb, "-maxrate", maxrate, "-bufsize", bufsize,
            "-pix_fmt", "p010le"
        ]
        for i, (index, channels, bitrate) in enumerate(streams):
            br = choose_audio_bitrate(channels, bitrate, audio_config)
            cmd += [f"-c:a:{i}", "aac", f"-b:a:{i}", str(br), f"-ac:{i}", str(channels)]
        cmd += ["-c:s", "copy", str(output_file)]
        subprocess.run(cmd, check=True)

# =============================
# PROCESS FOLDER
# =============================
def process_folder(folder: Path, cq: int, resolution: str, processing_folder: Path, config: dict):
    if not folder.exists():
        print(f"❌ Folder not found: {folder}")
        return

    filter_flags_default = config["encode"]["filters"]["default"]
    filter_flags_tv = config["encode"]["filters"]["tv"]

    folder_lower = str(folder).lower()
    if "\\tv\\" in folder_lower or "/tv/" in folder_lower:
        filter_flags = filter_flags_tv
        cq_default_key = f"tv_{resolution}"
    else:
        filter_flags = filter_flags_default
        cq_default_key = f"movie_{resolution}"

    if cq is None:
        cq = config["encode"]["cq"][cq_default_key]

    res_height = 1080 if resolution == "1080" else 720
    res_width = 1920 if resolution == "1080" else 1280

    processing_folder.mkdir(parents=True, exist_ok=True)

    for file in folder.rglob("*"):
        if file.suffix.lower() not in config["extensions"]:
            continue
        if any(tag in file.name.lower() for tag in ["ehx", "megusta"]):
            print(f"⏭️ Skipping: {file.name}")
            continue

        print("="*60)
        print(f"📁 Processing: {file.name}")

        temp_input = processing_folder / file.name
        shutil.copy2(file, temp_input)
        temp_output = processing_folder / f"{file.stem}{config['suffix']}{file.suffix}"

        run_ffmpeg(temp_input, temp_output, cq, res_width, res_height, filter_flags,
                   config["audio"], config["encode"])

        dest_file = file.parent / temp_output.name
        shutil.move(temp_output, dest_file)
        print(f"🚚 Moved {temp_output.name} → {dest_file.name}")

        # Cleanup
        if dest_file.exists():
            try:
                temp_input.unlink()
                file.unlink()
                print(f"🧹 Deleted original and processing copy")
            except Exception as e:
                print(f"⚠️ Could not delete files: {e}")

# =============================
# MAIN
# =============================
def main():
    parser = argparse.ArgumentParser(description="Batch encode videos")
    parser.add_argument("folder", help="Path to folder containing videos")
    parser.add_argument("--cq", type=int, help="Override default CQ")
    parser.add_argument("--r", "--resolution", dest="resolution", choices=["720","1080"], help="Target resolution (720 or 1080)")
    parser.add_argument("--processing", type=str, help="Processing folder")
    args = parser.parse_args()

    config_path = Path(__file__).parent / "config.xml"
    config = load_config_xml(config_path)

    cq = args.cq if args.cq is not None else None
    resolution = args.resolution if args.resolution else "1080"
    processing_folder = Path(args.processing) if args.processing else Path(config["processing_folder"])

    process_folder(Path(args.folder), cq, resolution, processing_folder, config)

if __name__ == "__main__":
    main()