"""
Pine Script Lab Router.

Endpoints for Pine Script generation, template browsing,
validation, backtesting, and code customization.
"""

from __future__ import annotations

import logging
from typing import Any, Dict, List, Optional

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel, Field

from app.dependencies import get_current_user
from app.models.user import User

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/pinescript", tags=["Pine Script Lab"])


# ── Schemas ──────────────────────────────────────────────────────────────

class GenerateRequest(BaseModel):
    description: str = Field(..., min_length=5, max_length=2000, description="Natural language description")
    parameters: Optional[Dict[str, Any]] = None


class TemplateRequest(BaseModel):
    template_id: str = Field(..., min_length=1, max_length=50)
    parameters: Optional[Dict[str, Any]] = None


class ValidateRequest(BaseModel):
    code: str = Field(..., min_length=10, max_length=10000)


class BacktestRequest(BaseModel):
    code: str = Field(..., min_length=10, max_length=10000)
    ticker: str = Field("SPY", min_length=1, max_length=20)
    period: str = Field("3y")
    initial_capital: float = Field(100000, ge=1000)
    commission_pct: float = Field(0.1, ge=0, le=5)


class CustomizeRequest(BaseModel):
    code: str = Field(..., min_length=10, max_length=10000)
    modification: str = Field(..., min_length=5, max_length=2000)


# ── Endpoints ────────────────────────────────────────────────────────────

@router.post("/generate")
async def generate_pinescript(
    data: GenerateRequest,
    user: User = Depends(get_current_user),
):
    """
    Generate Pine Script v5 code from a natural language description.
    Uses LLM (Groq) for intelligent code generation, falling back
    to template matching if LLM is unavailable.
    """
    from app.services.pinescript.generator import generate_from_description

    try:
        result = await generate_from_description(
            description=data.description,
            parameters=data.parameters,
        )
        return result
    except Exception as e:
        logger.error("Pine Script generation failed: %s", e, exc_info=True)
        raise HTTPException(status_code=500, detail="Generation failed")


@router.get("/templates")
async def list_templates(
    user: User = Depends(get_current_user),
):
    """List all available strategy templates."""
    from app.services.pinescript.generator import get_all_templates
    templates = get_all_templates()
    return {"total": len(templates), "templates": templates}


@router.post("/templates/generate")
async def generate_from_template_endpoint(
    data: TemplateRequest,
    user: User = Depends(get_current_user),
):
    """Generate Pine Script from a specific template with optional parameter overrides."""
    from app.services.pinescript.generator import generate_from_template

    try:
        result = generate_from_template(
            template_id=data.template_id,
            parameters=data.parameters,
        )
        return result
    except ValueError as e:
        raise HTTPException(status_code=404, detail=str(e))


@router.post("/validate")
async def validate_pinescript(
    data: ValidateRequest,
    user: User = Depends(get_current_user),
):
    """Validate Pine Script v5 syntax."""
    from app.services.pinescript.validator import validate_pine_script
    return validate_pine_script(data.code)


@router.post("/backtest")
async def backtest_pinescript(
    data: BacktestRequest,
    user: User = Depends(get_current_user),
):
    """
    Run a backtest on Pine Script code using historical data.
    Returns TradingView-style performance metrics, equity curve,
    trade log, and monthly returns.
    """
    from app.services.pinescript.pine_backtester import pine_backtester

    try:
        result = await pine_backtester.backtest(
            code=data.code,
            ticker=data.ticker,
            period=data.period,
            initial_capital=data.initial_capital,
            commission_pct=data.commission_pct,
        )
        return result
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        logger.error("Backtest failed: %s", e, exc_info=True)
        raise HTTPException(status_code=500, detail="Backtest failed")


@router.post("/customize")
async def customize_pinescript(
    data: CustomizeRequest,
    user: User = Depends(get_current_user),
):
    """Modify existing Pine Script via LLM-powered customization."""
    from app.services.pinescript.generator import customize_code

    try:
        result = await customize_code(
            existing_code=data.code,
            modification=data.modification,
        )
        return result
    except Exception as e:
        logger.error("Customization failed: %s", e, exc_info=True)
        raise HTTPException(status_code=500, detail="Customization failed")