from __future__ import annotations

import logging
import json
from pathlib import Path
from typing import Literal, Optional

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse
from fastapi.staticfiles import StaticFiles
from pydantic import BaseModel, Field

from db_agent.client import SqlAgentClient, default_client
from db_agent.log_utils import log_interaction
from db_agent.sql_executor import SqlExecutionResult, SqlValidationError, execute_sql

logger = logging.getLogger("db_agent_ui")


class QueryRequest(BaseModel):
    question: str = Field(..., description="Natural language question")
    tables: Optional[list[str]] = Field(default=None, description="Optional table hints")
    execute: bool = Field(default=False, description="Run the generated SQL against MSSQL")
    max_rows: int = Field(default=500, ge=1, description="Row cap applied via TOP clause")
    feedback: Optional[str] = Field(default=None, description="Optional user feedback tag")


class QueryResponse(BaseModel):
    sql: str
    summary: str
    sanitized_sql: Optional[str] = None
    rows: Optional[list[dict[str, object]]] = None
    columns: Optional[list[str]] = None
    row_count: Optional[int] = None
    llm_warning: Optional[str] = None
    execution_status: Optional[str] = None
    execution_error: Optional[str] = None
    user_feedback: Optional[str] = None


app = FastAPI(title="SugarScale SQL Agent UI", version="0.1.0")
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

frontend_dir = Path(__file__).resolve().parent.parent / "frontend"
static_dir = frontend_dir / "static"
if static_dir.exists():
    app.mount("/static", StaticFiles(directory=static_dir), name="static")

_agent_client: Optional[SqlAgentClient] = None


def get_client() -> SqlAgentClient:
    global _agent_client
    if _agent_client is None:
        _agent_client = default_client()
    return _agent_client


class FeedbackRequest(BaseModel):
    question: str = Field(..., description="Question that produced the answer")
    sql: str = Field(..., description="Generated SQL that was reviewed")
    summary: Optional[str] = None
    sanitized_sql: Optional[str] = None
    feedback: Literal["correct", "incorrect"] = Field(..., description="User feedback tag")


@app.post("/api/query", response_model=QueryResponse)
def query_endpoint(payload: QueryRequest) -> QueryResponse:
    client = get_client()
    response = client.query(question=payload.question, table_hints=payload.tables)

    sql = response.get("sql", "").strip()
    summary = response.get("summary", "").strip()
    warning = response.get("llm_warning")
    raw_response = json.dumps(response, ensure_ascii=False)
    sanitized_sql = None
    rows = None
    columns = None
    row_count = None
    execution_status = None
    execution_error = None

    normalized_sql = sql.lstrip()
    has_sql = bool(normalized_sql)
    sql_is_select = normalized_sql.lower().startswith("select") if has_sql else False

    if payload.execute:
        if not has_sql:
            warning = warning or "Model did not return executable SQL; nothing was run."
        elif not sql_is_select:
            warning = warning or "Model did not return a valid SELECT statement; execution skipped."
        else:
            try:
                exec_result: SqlExecutionResult = execute_sql(
                    normalized_sql,
                    max_rows=payload.max_rows,
                )
            except SqlValidationError as exc:
                execution_error = str(exc)
                raise HTTPException(status_code=400, detail=str(exc)) from exc
            except Exception as exc:  # pylint: disable=broad-except
                logger.exception("SQL execution error")
                execution_error = str(exc)
                raise HTTPException(status_code=500, detail="SQL execution failed") from exc
            else:
                sanitized_sql = exec_result.sql
                rows = exec_result.rows
                columns = exec_result.columns
                row_count = len(rows)
                execution_status = "success"

    log_interaction(
        question=payload.question,
        generated_sql=sql,
        summary=summary,
        sanitized_sql=sanitized_sql,
        row_count=row_count,
        execution_status=execution_status,
        execution_error=execution_error,
        raw_response=raw_response,
        user_feedback=payload.feedback,
        metadata={
            "source": "ui",
            "execute": payload.execute,
            "tables": payload.tables,
            "llm_warning": warning,
        },
    )

    return QueryResponse(
        sql=sql,
        summary=summary,
        sanitized_sql=sanitized_sql,
        rows=rows,
        columns=columns,
        row_count=row_count,
        llm_warning=warning,
        execution_status=execution_status,
        execution_error=execution_error,
        user_feedback=payload.feedback,
    )


@app.post("/api/feedback")
def record_feedback(payload: FeedbackRequest) -> dict[str, str]:
    feedback_value = payload.feedback.lower()

    log_interaction(
        question=payload.question,
        generated_sql=payload.sql,
        summary=payload.summary or "",
        sanitized_sql=payload.sanitized_sql,
        row_count=None,
        execution_status=None,
        execution_error=None,
        raw_response=None,
        user_feedback=feedback_value,
        metadata={
            "source": "ui-feedback",
            "feedback_only": True,
        },
    )

    return {"status": "recorded"}


@app.get("/health")
def healthcheck() -> dict[str, str]:
    return {"status": "ok"}


@app.get("/")
def index() -> FileResponse:
    return FileResponse(frontend_dir / "index.html")