import os
import subprocess
import re
from PyQt6.QtCore import QThread, pyqtSignal

class MediaConverter(QThread):
    progress_signal = pyqtSignal(str)       # Mensaje de estado
    finished_signal = pyqtSignal(bool, str) # (Éxito?, Mensaje final)

    def __init__(self, input_file, output_file, preset_key, bin_dir="bin"):
        super().__init__()
        self.input_file = input_file
        self.output_file = output_file
        self.preset_key = preset_key
        self.bin_dir = os.path.abspath(bin_dir)

    def run(self):
        ffmpeg_exe = os.path.join(self.bin_dir, "ffmpeg.exe")

        if not os.path.exists(ffmpeg_exe):
            self.finished_signal.emit(False, "No se encontró ffmpeg.exe en la carpeta bin.")
            return

        if not os.path.exists(self.input_file):
            self.finished_signal.emit(False, "El archivo de entrada no existe.")
            return

        # Configuración de argumentos según el preset
        if self.preset_key == "mp4_std":
            # MP4 Estándar sin reescalado
            codec_args = ["-c:v", "libx264", "-c:a", "aac"]

        elif self.preset_key == "mp4_1080p":
            # MP4 Max 1080p Verticales (mantiene aspecto, no escala si es <= 1080)
            codec_args = ["-vf", "scale=-2:'min(1080,ih)'", "-c:v", "libx264", "-c:a", "aac"]
            
        elif self.preset_key == "mp3_192k":
            # Estéreo completo a MP3 192 kbps
            codec_args = ["-vn", "-c:a", "libmp3lame", "-b:a", "192k"]
            
        elif self.preset_key == "mp3_ch1":
            # Solo Canal 1 (Izquierdo / Left) -> Mono MP3 192 kbps
            codec_args = ["-vn", "-af", "pan=mono|c0=c0", "-c:a", "libmp3lame", "-b:a", "192k"]
            
        elif self.preset_key == "mp3_ch2":
            # Solo Canal 2 (Derecho / Right) -> Mono MP3 192 kbps
            codec_args = ["-vn", "-af", "pan=mono|c0=c1", "-c:a", "libmp3lame", "-b:a", "192k"]
            
        else:
            self.finished_signal.emit(False, "Preset no reconocido.")
            return

        # Sobrescribir archivo de salida si ya existe (-y)
        command = [ffmpeg_exe, "-y", "-i", self.input_file] + codec_args + [self.output_file]

        try:
            startupinfo = None
            if os.name == 'nt':
                startupinfo = subprocess.STARTUPINFO()
                startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW

            process = subprocess.Popen(
                command,
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT,
                text=True,
                startupinfo=startupinfo,
                encoding='utf-8',
                errors='replace'
            )

            for line in process.stdout:
                line_str = line.strip()
                if line_str:
                    if "time=" in line_str:
                        match = re.search(r'time=(\d{2}:\d{2}:\d{2}\.\d{2})', line_str)
                        if match:
                            self.progress_signal.emit(f"Procesando... Tiempo: {match.group(1)}")

            process.wait()

            if process.returncode == 0:
                self.finished_signal.emit(True, "¡Conversión completada con éxito!")
            else:
                self.finished_signal.emit(False, "Ocurrió un error durante la conversión con FFmpeg.")

        except Exception as e:
            self.finished_signal.emit(False, f"Error de ejecución: {str(e)}")