import ollama
import json
import asyncio
from config import settings

SYSTEM_PROMPT = """You are a professional chef assistant. You MUST respond with valid JSON only — no markdown, no explanation outside the JSON. You prioritize:
1. Using ingredients that expire soonest
2. Nutritional variety across the week
3. Avoiding meals eaten in the past 7 days
4. Practical home recipes under 60 minutes"""


def _get_client():
    return ollama.Client(host=settings.ollama_host)


def _chat_sync(messages: list) -> str:
    client = _get_client()
    response = client.chat(
        model=settings.model_name,
        messages=messages,
        format="json",
        options={"temperature": 0.7, "num_predict": 4096},
    )
    return response["message"]["content"]


async def _chat(messages: list) -> dict:
    loop = asyncio.get_event_loop()
    raw = await loop.run_in_executor(None, lambda: _chat_sync(messages))
    try:
        return json.loads(raw)
    except json.JSONDecodeError as e:
        raise ValueError(f"Ollama returned invalid JSON: {e}. Raw: {raw[:200]}")


async def generate_weekly_menu(pantry_context: dict) -> dict:
    """Generate a 7-day rotating meal plan based on pantry state."""
    user_message = f"""Given the following pantry and recent meal history, generate a 7-day rotating meal plan.

PANTRY STATE:
{json.dumps(pantry_context, indent=2)}

RULES:
- Each day needs breakfast, lunch, and dinner
- No meal should repeat within the same week
- No meal should repeat a meal eaten in the last 7 days (see recent_meals)
- Prioritize ingredients expiring within 3 days (see expiring_soon)
- Each recipe should only use pantry ingredients OR common staples (salt, pepper, oil, etc.)
- Keep each meal practical — under 60 minutes

Respond ONLY with this JSON structure:
{{
  "week_plan": {{
    "monday": {{
      "breakfast": {{"name": "...", "ingredients": ["item1", "item2"], "instructions": "...", "time_minutes": 20}},
      "lunch": {{"name": "...", "ingredients": [...], "instructions": "...", "time_minutes": 30}},
      "dinner": {{"name": "...", "ingredients": [...], "instructions": "...", "time_minutes": 45}}
    }},
    "tuesday": {{ ... }},
    "wednesday": {{ ... }},
    "thursday": {{ ... }},
    "friday": {{ ... }},
    "saturday": {{ ... }},
    "sunday": {{ ... }}
  }},
  "notes": "brief explanation of choices"
}}"""

    messages = [
        {"role": "system", "content": SYSTEM_PROMPT},
        {"role": "user", "content": user_message},
    ]

    return await _chat(messages)


async def generate_grocery_list(menu_plan: dict, pantry_context: dict) -> dict:
    """Generate a minimal grocery list based on the menu plan and current pantry."""
    user_message = f"""Given the weekly meal plan and current pantry, generate a minimal grocery list.

MEAL PLAN:
{json.dumps(menu_plan, indent=2)}

CURRENT PANTRY:
{json.dumps(pantry_context["available_ingredients"], indent=2)}

RULES:
- Only list ingredients NOT already sufficiently in the pantry
- Consolidate duplicate ingredients across meals (buy once for the week)
- Group items by store section (produce, dairy, protein, pantry, frozen, bakery)
- Estimate realistic retail costs in USD
- Prefer bulk when ingredient appears in 3+ meals

Respond ONLY with this JSON:
{{
  "items": [
    {{
      "name": "...",
      "quantity": 2.0,
      "unit": "lbs",
      "store_section": "produce",
      "estimated_cost": 3.50,
      "used_in_meals": ["Chicken Stir Fry", "Chicken Soup"],
      "reason": "not in pantry"
    }}
  ],
  "total_estimate": 45.00,
  "shopping_notes": "..."
}}"""

    messages = [
        {"role": "system", "content": SYSTEM_PROMPT},
        {"role": "user", "content": user_message},
    ]

    return await _chat(messages)


async def suggest_recipe(pantry_context: dict) -> dict:
    """Suggest one recipe using available pantry ingredients."""
    user_message = f"""Suggest ONE recipe I can make right now using only these pantry ingredients (plus common staples).

PANTRY:
{json.dumps(pantry_context["available_ingredients"], indent=2)}

Respond ONLY with this JSON:
{{
  "recipe": {{
    "name": "...",
    "meal_type": "dinner",
    "ingredients": [{{"name": "...", "quantity": 1.0, "unit": "cup"}}],
    "instructions": "Step 1... Step 2...",
    "time_minutes": 30,
    "serves": 2
  }}
}}"""

    messages = [
        {"role": "system", "content": SYSTEM_PROMPT},
        {"role": "user", "content": user_message},
    ]

    return await _chat(messages)


async def get_available_models() -> list:
    """Get list of available Ollama model names."""
    def _list_models_sync():
        client = _get_client()
        try:
            models_resp = client.list()
            return [m["name"] for m in models_resp.get("models", [])]
        except Exception:
            return []

    loop = asyncio.get_event_loop()
    return await loop.run_in_executor(None, _list_models_sync)