from __future__ import annotations

import sqlite3
from dataclasses import dataclass
from pathlib import Path
from typing import Any

from django.conf import settings
from django.http import HttpRequest, HttpResponse
from django.shortcuts import render


@dataclass
class TrialRow:
    ann_return: float | None
    ann_vol: float | None
    max_drawdown: float | None
    sharpe: float | None
    trades_per_year: float | None
    ts_utc: str | None
    run_id: str | None
    config_path: str | None


def _db_path() -> Path:
    return Path(getattr(settings, "QFR_EXPERIMENTS_DB"))


def _connect() -> sqlite3.Connection:
    con = sqlite3.connect(str(_db_path()))
    con.row_factory = sqlite3.Row
    return con


def index(request: HttpRequest) -> HttpResponse:
    return render(
        request,
        "lab/index.html",
        {
            "db_path": str(_db_path()),
        },
    )


def top_trials(request: HttpRequest) -> HttpResponse:
    limit = int(request.GET.get("limit", "50"))
    limit = max(10, min(500, limit))

    rows: list[dict[str, Any]] = []
    summary: dict[str, Any] = {}
    with _connect() as con:
        cur = con.execute(
            """
            SELECT ann_return, ann_vol, max_drawdown, sharpe, trades_per_year, ts_utc, run_id, config_path
            FROM trials
            WHERE ann_return IS NOT NULL
            ORDER BY ann_return DESC
            LIMIT ?
            """,
            (limit,),
        )
        rows = [dict(r) for r in cur.fetchall()]

        cur2 = con.execute(
            """
            SELECT
              COUNT(*) AS n,
              MAX(ann_return) AS best_ann,
              MIN(max_drawdown) AS worst_dd,
              MIN(trades_per_year) AS min_tpy,
              MAX(trades_per_year) AS max_tpy
            FROM trials
            """
        )
        summary = dict(cur2.fetchone())

    return render(
        request,
        "lab/top_trials.html",
        {
            "rows": rows,
            "summary": summary,
            "limit": limit,
        },
    )


def best_artifacts(request: HttpRequest) -> HttpResponse:
    limit = int(request.GET.get("limit", "50"))
    limit = max(10, min(500, limit))

    rows: list[dict[str, Any]] = []
    with _connect() as con:
        cur = con.execute(
            """
            SELECT id, ts_utc, config_path, out_equity, out_weights, out_trades,
                   ann_return, ann_vol, max_drawdown, trades_per_year, params_json
            FROM best_artifacts
            ORDER BY id DESC
            LIMIT ?
            """,
            (limit,),
        )
        rows = [dict(r) for r in cur.fetchall()]

    return render(
        request,
        "lab/best_artifacts.html",
        {
            "rows": rows,
            "limit": limit,
        },
    )