import argparse
import json
from pathlib import Path
from typing import Any, Dict, List, Optional

from src.config import (
    ENCODED_DIR,
    PROMPTS_DIR,
    RAW_DATA_PATH,
)
from src.generator import Generator


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Encode dialogues into DAS format and generate context.")
    parser.add_argument(
        "--input_path",
        type=str,
        default=str(RAW_DATA_PATH),
        help="Path to raw dialogue JSON file.",
    )
    parser.add_argument(
        "--output_path",
        type=str,
        default=str(ENCODED_DIR / "dailydialog_encoded.json"),
        help="Path to save encoded output JSON.",
    )
    parser.add_argument(
        "--encode_prompt",
        type=str,
        default=str(PROMPTS_DIR / "das_encode.md"),
        help="Path to DAS encode prompt file.",
    )
    parser.add_argument(
        "--context_prompt",
        type=str,
        default=str(PROMPTS_DIR / "das_context.md"),
        help="Path to DAS context prompt file.",
    )
    parser.add_argument(
        "--functions_path",
        type=str,
        default=str(PROMPTS_DIR / "das_functions.json"),
        help="Path to DAS function definitions JSON.",
    )
    parser.add_argument(
        "--model",
        type=str,
        default=None,
        help="Model alias from model_registry.py",
    )
    parser.add_argument(
        "--max_instances",
        type=int,
        default=None,
        help="Optional cap on number of dialogues to process.",
    )
    parser.add_argument(
        "--start_idx",
        type=int,
        default=0,
        help="Optional start index for slicing input data.",
    )
    parser.add_argument(
        "--end_idx",
        type=int,
        default=None,
        help="Optional end index for slicing input data.",
    )
    parser.add_argument(
        "--dont_use_cached",
        action="store_true",
        help="Disable cached prompt responses.",
    )
    return parser.parse_args()


def load_json(path: str) -> Any:
    return json.loads(Path(path).read_text(encoding="utf-8"))


def save_json(path: str, data: Any) -> None:
    output_path = Path(path)
    output_path.parent.mkdir(parents=True, exist_ok=True)
    output_path.write_text(
        json.dumps(data, indent=2, ensure_ascii=False),
        encoding="utf-8",
    )


def preprocess_conversation(dialogue_turns: List[str]) -> str:
    return "\n".join(dialogue_turns)


def preprocess_dailydialogue(
    data: List[Dict[str, Any]],
    functions: List[Dict[str, Any]],
) -> List[Dict[str, Any]]:
    processed: List[Dict[str, Any]] = []

    for item in data:
        new_item = dict(item)
        new_item["conversation"] = preprocess_conversation(item["dialogue"])
        new_item["functions"] = functions
        processed.append(new_item)

    return processed


def create_encoding_prompts(
    generator: Generator,
    data: List[Dict[str, Any]],
    prompt_path: str,
) -> tuple[list[list[dict[str, str]]], Optional[Dict[str, Any]]]:
    return generator.build_prompts(prompt_path, data)


def merge_encoding_responses(
    original_data: List[Dict[str, Any]],
    responses: List[str],
) -> List[Dict[str, Any]]:
    merged: List[Dict[str, Any]] = []

    for item, response_text in zip(original_data, responses):
        response_json = Generator.parse_json_response(response_text)
        new_item = dict(item)
        new_item["das_encoding"] = response_json["das_encoding"]
        merged.append(new_item)

    return merged


def create_context_input(
    data_with_encoding: List[Dict[str, Any]],
) -> List[Dict[str, Any]]:
    """
    Prepare items for the context prompt.
    The DAS context prompt loops over 'das_encoding',
    so we just pass the data through.
    """
    prepared: List[Dict[str, Any]] = []

    for item in data_with_encoding:
        new_item = dict(item)
        prepared.append(new_item)

    return prepared


def merge_context_responses(
    data_with_encoding: List[Dict[str, Any]],
    responses: List[str],
) -> List[Dict[str, Any]]:
    merged: List[Dict[str, Any]] = []

    for item, response_text in zip(data_with_encoding, responses):
        response_json = Generator.parse_json_response(response_text)
        new_item = dict(item)
        new_item["context"] = response_json["context"]
        merged.append(new_item)

    return merged


def main() -> None:
    args = parse_args()

    raw_data = load_json(args.input_path)
    if not isinstance(raw_data, list):
        raise ValueError("Input JSON must be a list of dialogue objects.")

    sliced_data = raw_data[args.start_idx:args.end_idx]
    if args.max_instances is not None:
        sliced_data = sliced_data[: args.max_instances]

    functions = load_json(args.functions_path)
    if not isinstance(functions, list):
        raise ValueError("das_functions.json must be a list.")

    generator = Generator(
        model_alias=args.model,
        use_cache=not args.dont_use_cached,
    )

    # Step 1: build encode prompts
    processed_data = preprocess_dailydialogue(sliced_data, functions)
    encode_prompts, encode_response_format = create_encoding_prompts(
        generator=generator,
        data=processed_data,
        prompt_path=args.encode_prompt,
    )

    # Step 2: run encoding
    encode_responses = generator.prompt(
        prompts=encode_prompts,
        response_format=encode_response_format,
        dont_use_cached=args.dont_use_cached,
    )
    encoded_data = merge_encoding_responses(sliced_data, encode_responses)

    # Step 3: build context prompts
    context_input = create_context_input(encoded_data)
    context_prompts, context_response_format = generator.build_prompts(
        args.context_prompt,
        context_input,
    )

    # Step 4: run context generation
    context_responses = generator.prompt(
        prompts=context_prompts,
        response_format=context_response_format,
        dont_use_cached=args.dont_use_cached,
    )
    final_data = merge_context_responses(encoded_data, context_responses)

    # Step 5: save
    save_json(args.output_path, final_data)
    print(f"Saved encoded data to: {args.output_path}")
    generator.print_usage_summary(stage="Encode")


if __name__ == "__main__":
    main()