from google.cloud import translate_v2 as translate

from ..core.config import settings
from ..core.logging import get_logger

logger = get_logger(__name__)

class TranslateService:
    def __init__(self):
        if settings.translate_api_key:
            self.client = translate.Client()
        else:
            logger.warning("Google Translate API key not configured")
            self.client = None

    async def translate_vtt(
        self, vtt_content: str, target_language: str, source_language: str = "en"
    ) -> str:
        """
        Translate VTT content while preserving timing and structure.

        Args:
            vtt_content: The VTT file content to translate
            target_language: The language code to translate to (e.g., 'es', 'fr')
            source_language: The source language code (default: 'en')
        """
        if not self.client:
            raise ValueError("Google Translate not configured")

        # Parse VTT to extract cues
        cues = self._parse_vtt_cues(vtt_content)

        # Extract text for translation
        texts_to_translate = [cue["text"] for cue in cues]

        if not texts_to_translate:
            return vtt_content

        try:
            # Translate all texts in batch
            results = self.client.translate(
                texts_to_translate,
                target_language=target_language,
                source_language=source_language  # Use parameter instead of hardcoded "en"
            )

            # Rebuild VTT with translated text
            translated_cues = []
            for i, cue in enumerate(cues):
                translated_text = results[i]["translatedText"] if isinstance(results, list) else results["translatedText"]
                translated_cues.append({
                    "start": cue["start"],
                    "end": cue["end"],
                    "text": translated_text
                })

            return self._build_vtt(translated_cues)

        except Exception as e:
            logger.error(f"Translation failed: {e}")
            raise

    def _parse_vtt_cues(self, vtt_content: str) -> list[dict[str, str]]:
        """Parse VTT content and extract timing and text cues"""
        lines = vtt_content.strip().split('\n')
        cues = []
        current_cue = {}

        for line in lines:
            line = line.strip()

            # Skip WEBVTT header and empty lines
            if line == "WEBVTT" or line == "" or line.startswith("NOTE"):
                continue

            # Check if line contains timing
            if " --> " in line:
                timing_parts = line.split(" --> ")
                current_cue = {
                    "start": timing_parts[0].strip(),
                    "end": timing_parts[1].strip(),
                    "text": ""
                }
            elif current_cue and line:
                # This is subtitle text
                if current_cue.get("text"):
                    current_cue["text"] += " " + line
                else:
                    current_cue["text"] = line

                # If next line is empty or timing, cue is complete
                # For simplicity, we'll add the cue here and handle multi-line in a more robust way
                if current_cue["text"]:
                    cues.append(current_cue.copy())
                    current_cue = {}

        # Add final cue if exists
        if current_cue and current_cue.get("text"):
            cues.append(current_cue)

        return cues

    def _build_vtt(self, cues: list[dict[str, str]]) -> str:
        """Build VTT content from cues"""
        vtt_lines = ["WEBVTT", ""]

        for cue in cues:
            vtt_lines.append(f"{cue['start']} --> {cue['end']}")
            vtt_lines.append(cue["text"])
            vtt_lines.append("")  # Empty line between cues

        return "\n".join(vtt_lines)


# Global service instance
translate_service = TranslateService()