"""
Trading journal API endpoints.
"""
from datetime import date
from decimal import Decimal
from typing import List, Optional

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session
from sqlalchemy import func

from app.core.database import get_db
from app.api.deps import CurrentUser
from app.models.journal import TradeJournal, JournalStatus
from app.schemas.journal import (
    TradeJournalCreate,
    TradeJournalUpdate,
    TradeJournalResponse,
    TradeJournalStats,
)

router = APIRouter(prefix="/api/journal", tags=["journal"])


@router.post("", response_model=TradeJournalResponse, status_code=201)
async def create_journal(
    data: TradeJournalCreate,
    current_user: CurrentUser,
    db: Session = Depends(get_db),
):
    journal = TradeJournal(
        user_id=current_user.id,
        **data.model_dump(),
    )
    db.add(journal)
    db.commit()
    db.refresh(journal)
    return journal


@router.get("", response_model=List[TradeJournalResponse])
async def list_journals(
    current_user: CurrentUser,
    db: Session = Depends(get_db),
    status: Optional[str] = Query(None),
    stock_code: Optional[str] = Query(None),
    start_date: Optional[date] = Query(None),
    end_date: Optional[date] = Query(None),
    skip: int = Query(0, ge=0),
    limit: int = Query(50, ge=1, le=200),
):
    query = db.query(TradeJournal).filter(TradeJournal.user_id == current_user.id)

    if status:
        query = query.filter(TradeJournal.status == status)
    if stock_code:
        query = query.filter(TradeJournal.stock_code == stock_code)
    if start_date:
        query = query.filter(TradeJournal.entry_date >= start_date)
    if end_date:
        query = query.filter(TradeJournal.entry_date <= end_date)

    journals = (
        query.order_by(TradeJournal.entry_date.desc(), TradeJournal.created_at.desc())
        .offset(skip)
        .limit(limit)
        .all()
    )
    return journals


@router.get("/stats", response_model=TradeJournalStats)
async def get_journal_stats(
    current_user: CurrentUser,
    db: Session = Depends(get_db),
):
    journals = (
        db.query(TradeJournal)
        .filter(TradeJournal.user_id == current_user.id)
        .all()
    )

    total = len(journals)
    open_trades = sum(1 for j in journals if j.status == JournalStatus.OPEN)
    closed = [j for j in journals if j.status == JournalStatus.CLOSED]
    closed_count = len(closed)

    closed_with_pnl = [j for j in closed if j.profit_loss_pct is not None]
    win_count = sum(1 for j in closed_with_pnl if j.profit_loss_pct > 0)
    loss_count = sum(1 for j in closed_with_pnl if j.profit_loss_pct <= 0)

    win_rate = None
    avg_pnl_pct = None
    max_profit = None
    max_loss = None
    total_pnl = None

    if closed_with_pnl:
        win_rate = Decimal(win_count) / Decimal(len(closed_with_pnl)) * 100
        pcts = [j.profit_loss_pct for j in closed_with_pnl]
        avg_pnl_pct = sum(pcts) / len(pcts)
        max_profit = max(pcts)
        max_loss = min(pcts)

    closed_with_pl = [j for j in closed if j.profit_loss is not None]
    if closed_with_pl:
        total_pnl = sum(j.profit_loss for j in closed_with_pl)

    return TradeJournalStats(
        total_trades=total,
        open_trades=open_trades,
        closed_trades=closed_count,
        win_count=win_count,
        loss_count=loss_count,
        win_rate=win_rate,
        avg_profit_loss_pct=avg_pnl_pct,
        max_profit_pct=max_profit,
        max_loss_pct=max_loss,
        total_profit_loss=total_pnl,
    )


@router.get("/{journal_id}", response_model=TradeJournalResponse)
async def get_journal(
    journal_id: int,
    current_user: CurrentUser,
    db: Session = Depends(get_db),
):
    journal = (
        db.query(TradeJournal)
        .filter(TradeJournal.id == journal_id, TradeJournal.user_id == current_user.id)
        .first()
    )
    if not journal:
        raise HTTPException(status_code=404, detail="Journal not found")
    return journal


@router.put("/{journal_id}", response_model=TradeJournalResponse)
async def update_journal(
    journal_id: int,
    data: TradeJournalUpdate,
    current_user: CurrentUser,
    db: Session = Depends(get_db),
):
    journal = (
        db.query(TradeJournal)
        .filter(TradeJournal.id == journal_id, TradeJournal.user_id == current_user.id)
        .first()
    )
    if not journal:
        raise HTTPException(status_code=404, detail="Journal not found")

    update_data = data.model_dump(exclude_unset=True)
    for field, value in update_data.items():
        setattr(journal, field, value)

    # Auto-calculate profit/loss when closing
    if data.exit_price is not None and journal.entry_price is not None:
        if journal.trade_type.value == "buy":
            journal.profit_loss = (data.exit_price - journal.entry_price) * (journal.quantity or 1)
            journal.profit_loss_pct = (data.exit_price - journal.entry_price) / journal.entry_price * 100
        else:
            journal.profit_loss = (journal.entry_price - data.exit_price) * (journal.quantity or 1)
            journal.profit_loss_pct = (journal.entry_price - data.exit_price) / journal.entry_price * 100

    # Auto-close when exit info is provided
    if data.exit_price is not None and data.exit_date is not None and journal.status == JournalStatus.OPEN:
        journal.status = JournalStatus.CLOSED

    db.commit()
    db.refresh(journal)
    return journal