import time

from generation.script_generator import get_generator
from processing.pdf_reader import extract_text_from_pdf
from processing.url_fetcher import fetch_paper_from_url
from synthesis.tts_engine import get_tts_engine
from utils.config import (
    MAX_CONTEXT_CHARS,
)
from utils.history import save_to_history


class PodcastAgent:
    def __init__(
        self,
        provider_mode="own_inference",
        own_base_url=None,
        own_api_key=None,
        own_model=None,
        openai_key=None,
        openai_model=None,
        tts_provider="elevenlabs",
        elevenlabs_key=None,
        host_voice=None,
        guest_voice=None,
        max_tokens=None,
        target_dialogue_count=15,
        context_limit=None,
        persona_mode="friendly_explainer",
    ):
        """
        Initialize PodcastAgent with user-provided settings (BYOK).

        Args:
            provider_mode: "own_inference" or "openai"
            own_base_url: Base URL for own inference server
            own_api_key: API key for own inference server
            own_model: Model name for own inference server
            openai_key: OpenAI API key
            openai_model: OpenAI model name
            tts_provider: "elevenlabs" (ElevenLabs required)
            elevenlabs_key: ElevenLabs API key (required)
            host_voice: Voice ID for host
            guest_voice: Voice ID for guest
            max_tokens: Maximum tokens for generation
            target_dialogue_count: Target number of dialogue exchanges (default: 15)
            context_limit: Maximum characters for multi-paper processing (default: MAX_CONTEXT_CHARS)
            persona_mode: Podcast persona mode (default: "friendly_explainer")
        """
        self.logs = []
        self.provider_mode = provider_mode  # "own_inference" or "openai"
        self.own_base_url = own_base_url
        self.own_api_key = own_api_key
        self.own_model = own_model
        self.openai_key = openai_key
        self.openai_model = openai_model
        self.tts_provider = tts_provider
        self.elevenlabs_key = elevenlabs_key
        self.host_voice = host_voice
        self.guest_voice = guest_voice
        self.max_tokens = max_tokens
        self.target_dialogue_count = target_dialogue_count
        self.context_limit = context_limit if context_limit else MAX_CONTEXT_CHARS
        self.persona_mode = persona_mode

    def log(self, message):
        timestamp = time.strftime("%H:%M:%S")
        entry = f"[{timestamp}] {message}"
        print(entry)
        self.logs.append(entry)
        return entry

    def process(self, url: str = None, pdf_file=None):
        """
        Orchestrates the conversion from URL or uploaded PDF to Podcast.

        Args:
            url: Paper URL (arXiv or medRxiv)
            pdf_file: Uploaded PDF file object
        """
        # Determine source
        if pdf_file:
            yield self.log(
                f"Received uploaded PDF: {pdf_file.name if hasattr(pdf_file, 'name') else 'file'}"
            )
            pdf_path = pdf_file.name if hasattr(pdf_file, "name") else pdf_file
            source_ref = "Uploaded PDF"
        elif url:
            yield self.log(f"Received request for URL: {url}")

            # Step 1: Fetch Paper
            yield self.log("Thinking: I need to download the paper first.")
            yield self.log(f"Tool Call: fetch_paper({url})")
            pdf_path = fetch_paper_from_url(url)
            if not pdf_path:
                yield self.log("Error: Failed to download paper.")
                return None, "\n".join(self.logs)
            yield self.log(f"Paper downloaded to: {pdf_path}")
            source_ref = url
        else:
            yield self.log(
                "Error: No input provided. Please provide either a URL or upload a PDF."
            )
            return None, "\n".join(self.logs)

        # Step 2: Read PDF
        yield self.log("Thinking: Now I need to extract the text content.")
        yield self.log(f"Tool Call: read_pdf({pdf_path})")
        text = extract_text_from_pdf(pdf_path)
        if not text:
            yield self.log("Error: Failed to extract text.")
            return None, self.logs
        
        text_length = len(text)
        yield self.log(f"Extracted {text_length:,} characters.")
        
        # Check context limit
        if text_length > self.context_limit:
            yield self.log(f"⚠️ Context limit exceeded!")
            yield self.log(f"Paper size: {text_length:,} characters")
            yield self.log(f"Maximum allowed: {self.context_limit:,} characters")
            yield self.log("")
            yield self.log("❌ Error: Paper is too large to process with current settings.")
            yield self.log("")
            yield self.log("📋 How to fix:")
            yield self.log("  1. Open 'Advanced Options' below")
            yield self.log("  2. Enable 'Batch Mode'")
            yield self.log(f"  3. Adjust 'Max Context Limit' slider to at least {text_length:,} characters")
            yield self.log("  4. Try again")
            yield self.log("")
            return None, "\n".join(self.logs)

        # Step 3: Generate Script
        yield self.log(
            "Thinking: The text is ready. I will now generate a podcast script using the LLM."
        )
        if self.provider_mode == "demo":
            yield self.log("Using Demo Inference")
        elif self.provider_mode == "own_inference":
            yield self.log(f"Using Own Inference: {self.own_base_url}")
        else:
            yield self.log(f"Using OpenAI ({self.openai_model or 'gpt-4o-mini'})")
        yield self.log("Tool Call: generate_script(...)")
        generator = get_generator(
            provider_mode=self.provider_mode,
            own_base_url=self.own_base_url,
            own_api_key=self.own_api_key,
            own_model=self.own_model,
            openai_key=self.openai_key,
            openai_model=self.openai_model,
            max_tokens=self.max_tokens,
        )
        script = generator.generate_podcast_script(text, target_dialogue_count=self.target_dialogue_count, persona_mode=self.persona_mode)
        if not script:
            yield self.log("Error: Failed to generate script.")
            return None, self.logs
        yield self.log(f"Generated script with {len(script)} dialogue turns (target: {self.target_dialogue_count}).")

        # Step 4: Synthesize Audio
        yield self.log("Thinking: The script looks good. Sending it to the TTS engine.")
        tts_name = "ElevenLabs TTS" if self.tts_provider == "elevenlabs" else "Supertonic TTS (CPU)"
        yield self.log(f"Using {tts_name}")
        yield self.log("Tool Call: synthesize_podcast(...)")
        tts = get_tts_engine(
            tts_provider=self.tts_provider,
            custom_api_key=self.elevenlabs_key if self.tts_provider == "elevenlabs" else None,
            host_voice=self.host_voice,
            guest_voice=self.guest_voice
        )
        audio_path = tts.synthesize_dialogue(script)

        if not audio_path:
            yield self.log("Error: Failed to synthesize audio.")
            return None, self.logs

        yield self.log(f"Podcast generated successfully at: {audio_path}")

        # Save to history
        save_to_history(source_ref, audio_path, len(script))
        yield self.log("✓ Saved to history")

        return audio_path, "\n".join(self.logs)

    def process_multiple(self, urls: list = None, pdf_files: list = None):
        """
        Orchestrates the conversion from multiple URLs or PDFs to a single comprehensive Podcast.

        Args:
            urls: List of paper URLs (arXiv or medRxiv)
            pdf_files: List of uploaded PDF file objects
        """
        all_texts = []
        source_refs = []
        total_chars = 0

        # Process URLs
        if urls:
            yield self.log(f"Received {len(urls)} URLs to process.")
            yield self.log(f"Context limit: {self.context_limit:,} characters")

            for i, url in enumerate(urls, 1):
                yield self.log(f"\n=== Processing Paper {i}/{len(urls)} ===")
                yield self.log(f"URL: {url}")

                # Step 1: Fetch Paper
                yield self.log(f"Tool Call: fetch_paper({url})")
                pdf_path = fetch_paper_from_url(url)
                if not pdf_path:
                    yield self.log(f"Warning: Failed to download paper {i}, skipping.")
                    continue

                yield self.log(f"Paper {i} downloaded successfully.")

                # Step 2: Read PDF
                yield self.log(f"Tool Call: read_pdf({pdf_path})")
                text = extract_text_from_pdf(pdf_path)
                if not text:
                    yield self.log(
                        f"Warning: Failed to extract text from paper {i}, skipping."
                    )
                    continue

                text_length = len(text)
                yield self.log(f"Extracted {text_length:,} characters from paper {i}.")

                # Check context limit
                if total_chars + text_length > self.context_limit:
                    yield self.log(f"⚠️ Context limit reached!")
                    yield self.log(
                        f"Current total: {total_chars:,} chars + Paper {i}: {text_length:,} chars = {total_chars + text_length:,} chars"
                    )
                    yield self.log(f"Maximum allowed: {self.context_limit:,} chars")
                    yield self.log(
                        f"Stopping at {len(all_texts)} papers. Remaining papers will be skipped."
                    )
                    break

                all_texts.append(f"=== PAPER {i} ===\n{text}\n")
                source_refs.append(url)
                total_chars += text_length
                yield self.log(
                    f"✓ Paper {i} added. Total context: {total_chars:,} chars ({(total_chars / self.context_limit) * 100:.1f}% of limit)"
                )

        # Process PDFs
        if pdf_files:
            yield self.log(f"\nReceived {len(pdf_files)} PDF files to process.")
            if not urls:  # Only show limit if we didn't already show it for URLs
                yield self.log(f"Context limit: {self.context_limit:,} characters")

            for i, pdf_file in enumerate(pdf_files, 1):
                # Calculate paper number (continues from URL count)
                paper_num = (len(urls) if urls else 0) + i
                
                yield self.log(f"\n=== Processing PDF {i}/{len(pdf_files)} (Paper {paper_num}) ===")
                pdf_name = pdf_file.name if hasattr(pdf_file, "name") else f"file_{i}"
                yield self.log(f"File: {pdf_name}")

                pdf_path = pdf_file.name if hasattr(pdf_file, "name") else pdf_file

                # Read PDF
                yield self.log(f"Tool Call: read_pdf({pdf_path})")
                text = extract_text_from_pdf(pdf_path)
                if not text:
                    yield self.log(
                        f"Warning: Failed to extract text from PDF {i}, skipping."
                    )
                    continue

                text_length = len(text)
                yield self.log(f"Extracted {text_length:,} characters from PDF {i}.")

                # Check context limit
                if total_chars + text_length > self.context_limit:
                    yield self.log(f"⚠️ Context limit reached!")
                    yield self.log(
                        f"Current total: {total_chars:,} chars + PDF {i}: {text_length:,} chars = {total_chars + text_length:,} chars"
                    )
                    yield self.log(f"Maximum allowed: {self.context_limit:,} chars")
                    yield self.log(
                        f"Stopping at {len(all_texts)} files. Remaining items will be skipped."
                    )
                    break

                all_texts.append(f"=== PAPER {paper_num} ===\n{text}\n")
                source_refs.append(f"Uploaded PDF: {pdf_name}")
                total_chars += text_length
                yield self.log(
                    f"✓ PDF {i} added. Total context: {total_chars:,} chars ({(total_chars / self.context_limit) * 100:.1f}% of limit)"
                )

        if not all_texts:
            yield self.log("Error: No papers were successfully processed.")
            return None, "\n".join(self.logs)

        # Combine all texts
        yield self.log(f"\n✓ Successfully processed {len(all_texts)} papers")
        yield self.log(
            f"Total context: {total_chars:,} characters ({(total_chars / self.context_limit) * 100:.1f}% of limit)"
        )
        yield self.log(
            f"Thinking: Now I'll combine all papers into a comprehensive podcast script."
        )

        combined_text = "\n\n".join(all_texts)

        # Step 3: Generate Comprehensive Script
        yield self.log(
            "\nThinking: Creating a comprehensive podcast script covering all papers."
        )
        if self.provider_mode == "demo":
            yield self.log("Using Demo Inference")
        elif self.provider_mode == "own_inference":
            yield self.log(f"Using Own Inference: {self.own_base_url}")
        else:
            yield self.log(f"Using OpenAI ({self.openai_model or 'gpt-4o-mini'})")
        yield self.log("Tool Call: generate_script(...)")
        generator = get_generator(
            provider_mode=self.provider_mode,
            own_base_url=self.own_base_url,
            own_api_key=self.own_api_key,
            own_model=self.own_model,
            openai_key=self.openai_key,
            openai_model=self.openai_model,
            max_tokens=self.max_tokens,
        )

        # Add instruction for multi-paper script
        multi_paper_prompt = f"[MULTIPLE PAPERS - {len(all_texts)} papers total. Create a comprehensive podcast discussing all papers.]\n\n{combined_text}"
        script = generator.generate_podcast_script(multi_paper_prompt, target_dialogue_count=self.target_dialogue_count, persona_mode=self.persona_mode)

        if not script:
            yield self.log("Error: Failed to generate script.")
            return None, self.logs

        yield self.log(
            f"Generated comprehensive script with {len(script)} dialogue turns."
        )

        # Step 4: Synthesize Audio
        yield self.log(
            "\nThinking: The script looks good. Sending it to the TTS engine."
        )
        tts_name = "ElevenLabs TTS" if self.tts_provider == "elevenlabs" else "Supertonic TTS (CPU)"
        yield self.log(f"Using {tts_name}")
        yield self.log("Tool Call: synthesize_podcast(...)")
        tts = get_tts_engine(
            tts_provider=self.tts_provider,
            custom_api_key=self.elevenlabs_key if self.tts_provider == "elevenlabs" else None,
            host_voice=self.host_voice,
            guest_voice=self.guest_voice
        )
        audio_path = tts.synthesize_dialogue(script)

        if not audio_path:
            yield self.log("Error: Failed to synthesize audio.")
            return None, self.logs

        yield self.log(f"Podcast generated successfully at: {audio_path}")

        # Save to history
        source_ref = f"Multiple papers: {', '.join(source_refs[:3])}{'...' if len(source_refs) > 3 else ''}"
        save_to_history(source_ref, audio_path, len(script))
        yield self.log("✓ Saved to history")

        return audio_path, "\n".join(self.logs)