#!/usr/bin/env python3

import argparse
import json
import sys
from pathlib import Path
from urllib.error import HTTPError, URLError
from urllib.request import Request, urlopen

from providers.shared.temperature import TemperatureConstraint


ROOT = Path(__file__).resolve().parents[1]
DEFAULT_OUTPUT = ROOT / "conf" / "openrouter_models_live.json"
OPENROUTER_MODELS_URL = "https://openrouter.ai/api/v1/models"


def fetch_openrouter_models(url: str) -> dict:
    request = Request(
        url,
        headers={
            "Accept": "application/json",
            "User-Agent": "pal-mcp-server/openrouter-model-sync",
        },
    )

    with urlopen(request, timeout=30) as response:
        charset = response.headers.get_content_charset("utf-8")
        payload = response.read().decode(charset)

    data = json.loads(payload)
    if not isinstance(data, dict):
        raise ValueError("OpenRouter models payload must be a JSON object")
    return data


def _supports_parameter(model_data: dict, parameter: str) -> bool:
    supported = model_data.get("supported_parameters")
    return isinstance(supported, list) and parameter in supported


def _input_modalities(model_data: dict) -> list[str]:
    architecture = model_data.get("architecture")
    if not isinstance(architecture, dict):
        return []

    modalities = architecture.get("input_modalities")
    if not isinstance(modalities, list):
        return []

    return [str(item) for item in modalities]


def _infer_temperature_fields(model_name: str, model_data: dict) -> tuple[bool, str]:
    if _supports_parameter(model_data, "temperature"):
        return True, "range"

    supports_temperature, _constraint, _reason = TemperatureConstraint.resolve_settings(model_name)
    return supports_temperature, "fixed" if not supports_temperature else "range"


def convert_model(model_data: dict) -> dict | None:
    model_name = model_data.get("id")
    if not isinstance(model_name, str) or not model_name:
        return None

    modalities = _input_modalities(model_data)
    supports_temperature, temperature_constraint = _infer_temperature_fields(model_name, model_data)

    context_window = model_data.get("context_length") or 0
    top_provider = model_data.get("top_provider")
    if not isinstance(top_provider, dict):
        top_provider = {}

    max_output_tokens = top_provider.get("max_completion_tokens") or 0

    return {
        "model_name": model_name,
        "aliases": [],
        "context_window": int(context_window) if context_window else 0,
        "max_output_tokens": int(max_output_tokens) if max_output_tokens else 0,
        "supports_extended_thinking": _supports_parameter(model_data, "reasoning")
        or _supports_parameter(model_data, "include_reasoning"),
        "supports_json_mode": _supports_parameter(model_data, "response_format")
        or _supports_parameter(model_data, "structured_outputs"),
        "supports_function_calling": _supports_parameter(model_data, "tools"),
        "supports_images": "image" in modalities,
        "max_image_size_mb": 20.0 if "image" in modalities else 0.0,
        "supports_temperature": supports_temperature,
        "temperature_constraint": temperature_constraint,
        "description": model_data.get("description") or model_data.get("name") or "",
        "intelligence_score": 10,
        "allow_code_generation": False,
    }


def build_output_document(source: dict, source_url: str) -> dict:
    models = []
    for model_data in source.get("data", []):
        if not isinstance(model_data, dict):
            continue

        converted = convert_model(model_data)
        if converted:
            models.append(converted)

    models.sort(key=lambda item: item["model_name"])

    return {
        "_README": {
            "description": "Generated baseline OpenRouter catalogue for PAL MCP Server.",
            "source": source_url,
            "usage": "Generated by scripts/sync_openrouter_models.py. Curated overrides belong in conf/openrouter_models.json.",
            "field_notes": "Entries are conservative and intended as discovery data only. Curated manifest values override these at runtime.",
        },
        "models": models,
    }


def write_output(path: Path, document: dict) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    with path.open("w", encoding="utf-8", newline="\n") as handle:
        json.dump(document, handle, indent=2, ensure_ascii=False)
        handle.write("\n")


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Sync OpenRouter live model catalogue into PAL config.")
    parser.add_argument("--url", default=OPENROUTER_MODELS_URL, help="OpenRouter models endpoint")
    parser.add_argument(
        "--output",
        default=str(DEFAULT_OUTPUT),
        help="Path to the generated live OpenRouter manifest",
    )
    return parser.parse_args()


def main() -> int:
    args = parse_args()
    output_path = Path(args.output)

    try:
        source = fetch_openrouter_models(args.url)
        document = build_output_document(source, args.url)
        write_output(output_path, document)
    except (HTTPError, URLError, TimeoutError, ValueError, json.JSONDecodeError) as exc:
        print(f"Failed to sync OpenRouter models: {exc}", file=sys.stderr)
        return 1

    print(f"Wrote {len(document['models'])} OpenRouter models to {output_path}")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())