import os
import google.generativeai as genai
from pathlib import Path
import logging

logger = logging.getLogger(__name__)

class CoverageGenerator:
    def __init__(self):
        api_key = os.getenv("GOOGLE_API_KEY")
        if not api_key:
            raise ValueError("GOOGLE_API_KEY not found")

        genai.configure(api_key=api_key)
        self.model = genai.GenerativeModel('gemini-pro')
        self.chunk_size = 8000

    def count_tokens(self, text: str) -> int:
        """Estimate token count using simple word-based estimation"""
        words = text.split()
        return int(len(words) * 1.3)

    def chunk_screenplay(self, text: str) -> list:
        """Split screenplay into chunks with overlap for context"""
        logger.info("Chunking screenplay...")

        scenes = text.split("\n\n")
        chunks = []
        current_chunk = []
        current_size = 0
        overlap_scenes = 2

        for i, scene in enumerate(scenes):
            scene_size = self.count_tokens(scene)

            if current_size + scene_size > self.chunk_size and current_chunk:
                overlap = current_chunk[-overlap_scenes:] if len(current_chunk) > overlap_scenes else current_chunk
                chunks.append("\n\n".join(current_chunk))
                current_chunk = overlap + [scene]
                current_size = sum(self.count_tokens(s) for s in current_chunk)
            else:
                current_chunk.append(scene)
                current_size += scene_size

        if current_chunk:
            chunks.append("\n\n".join(current_chunk))

        logger.info(f"Split screenplay into {len(chunks)} chunks with context overlap")
        return chunks

    def generate_synopsis(self, chunk: str, chunk_num: int = 1, total_chunks: int = 1) -> str:
        """Generate synopsis for a single chunk"""
        logger.debug(f"Generating synopsis for chunk {chunk_num}/{total_chunks}")
        
        prompt = f"""As an experienced script analyst, analyze this section ({chunk_num}/{total_chunks}) of the screenplay.
        Focus on: plot developments, character development, narrative connections, themes
        
        Screenplay section:
        {chunk}"""

        try:
            response = self.model.generate_content(prompt)
            logger.debug(f"Generated synopsis for chunk {chunk_num}")
            return response.text
        except Exception as e:
            logger.error(f"Error processing chunk {chunk_num}: {str(e)}")
            return None

    def generate_final_synopsis(self, chunk_synopses: list) -> str:
        """Combine chunk synopses into final coverage"""
        logger.info("Generating final synopsis")
        
        combined_text = "\n\n".join([f"Section {i+1}:\n{synopsis}" 
                                   for i, synopsis in enumerate(chunk_synopses)])

        prompt = f"""Synthesize these section summaries into a comprehensive coverage document with:
        1. Complete narrative arc
        2. Character development
        3. Major themes
        4. Key turning points
        5. Core conflict and resolution

        Section summaries:
        {combined_text}"""

        try:
            response = self.model.generate_content(prompt)
            logger.info("Final synopsis generated")
            return response.text
        except Exception as e:
            logger.error(f"Error generating final synopsis: {str(e)}")
            return None

    def generate_coverage(self, screenplay_path: Path) -> bool:
        """Main method to generate coverage document"""
        logger.info("Starting coverage generation")

        try:
            with open(screenplay_path, 'r', encoding='utf-8') as f:
                screenplay_text = f.read()
                
            chunks = self.chunk_screenplay(screenplay_text)
            
            chunk_synopses = []
            for i, chunk in enumerate(chunks, 1):
                logger.info(f"Processing chunk {i}/{len(chunks)}")
                synopsis = self.generate_synopsis(chunk, i, len(chunks))
                if synopsis:
                    chunk_synopses.append(synopsis)
                else:
                    logger.error(f"Failed to process chunk {i}")
                    return False

            final_synopsis = self.generate_final_synopsis(chunk_synopses)
            if not final_synopsis:
                return False

            output_path = screenplay_path.parent / "coverage.txt"
            with open(output_path, 'w', encoding='utf-8') as f:
                f.write("SCREENPLAY COVERAGE\n\n")
                f.write(final_synopsis)

            logger.info("Coverage generation complete")
            return True
            
        except Exception as e:
            logger.error(f"Error in coverage generation: {str(e)}")
            return False