"""Routes for portfolio optimization (HRP, correlation, risk parity)."""

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

from models import ApiResponse
from route_utils import safe
import portfolio_service

router = APIRouter(prefix="/api/v1/portfolio")


class PortfolioOptimizeRequest(BaseModel):
    symbols: list[str] = Field(..., min_length=1, max_length=50)
    days: int = Field(default=365, ge=1, le=3650)


@router.post("/optimize", response_model=ApiResponse)
@safe
async def portfolio_optimize(request: PortfolioOptimizeRequest):
    """Compute HRP optimal weights for a list of symbols."""
    try:
        result = await portfolio_service.optimize_hrp(
            request.symbols, days=request.days
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    return ApiResponse(data=result)


@router.post("/correlation", response_model=ApiResponse)
@safe
async def portfolio_correlation(request: PortfolioOptimizeRequest):
    """Compute correlation matrix for a list of symbols."""
    try:
        result = await portfolio_service.compute_correlation(
            request.symbols, days=request.days
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    return ApiResponse(data=result)


@router.post("/risk-parity", response_model=ApiResponse)
@safe
async def portfolio_risk_parity(request: PortfolioOptimizeRequest):
    """Compute equal risk contribution weights for a list of symbols."""
    try:
        result = await portfolio_service.compute_risk_parity(
            request.symbols, days=request.days
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    return ApiResponse(data=result)


class ClusterRequest(BaseModel):
    symbols: list[str] = Field(..., min_length=3, max_length=50)
    days: int = Field(default=180, ge=30, le=3650)
    n_clusters: int | None = Field(default=None, ge=2, le=20)


class SimilarRequest(BaseModel):
    symbol: str = Field(..., min_length=1, max_length=20)
    universe: list[str] = Field(..., min_length=2, max_length=50)
    days: int = Field(default=180, ge=30, le=3650)
    top_n: int = Field(default=5, ge=1, le=20)


@router.post("/cluster", response_model=ApiResponse)
@safe
async def portfolio_cluster(request: ClusterRequest):
    """Cluster stocks by return similarity using t-SNE + KMeans."""
    try:
        result = await portfolio_service.cluster_stocks(
            request.symbols, days=request.days, n_clusters=request.n_clusters
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    return ApiResponse(data=result)


@router.post("/similar", response_model=ApiResponse)
@safe
async def portfolio_similar(request: SimilarRequest):
    """Find stocks most/least similar to a target by return correlation."""
    try:
        result = await portfolio_service.find_similar_stocks(
            request.symbol,
            request.universe,
            days=request.days,
            top_n=request.top_n,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    return ApiResponse(data=result)