"""Audit routes for viewing action records."""

from collections.abc import Callable
from typing import TypeVar

from fastapi import APIRouter, Depends, Query
from pydantic import BaseModel
from sqlalchemy import desc, func, select
from sqlalchemy.ext.asyncio import AsyncSession

from auth import require_permission
from database import get_db
from models import CounterRecord, Permission, RandomNumberOutcome, SumRecord, User
from pagination import (
    calculate_offset,
    calculate_total_pages,
    create_paginated_response,
)
from schemas import (
    CounterRecordResponse,
    PaginatedCounterRecords,
    PaginatedSumRecords,
    RandomNumberOutcomeResponse,
    SumRecordResponse,
)

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

R = TypeVar("R", bound=BaseModel)


async def paginate_with_user_email(
    db: AsyncSession,
    model: type[SumRecord] | type[CounterRecord],
    page: int,
    per_page: int,
    row_mapper: Callable[..., R],
) -> tuple[list[R], int, int]:
    """
    Generic pagination helper for audit records that need user email.

    Returns: (records, total, total_pages)
    """
    # Get total count
    count_result = await db.execute(select(func.count(model.id)))
    total = count_result.scalar() or 0

    # Get paginated records with user email
    offset = calculate_offset(page, per_page)
    query = (
        select(model, User.email)
        .join(User, model.user_id == User.id)
        .order_by(desc(model.created_at))
        .offset(offset)
        .limit(per_page)
    )
    result = await db.execute(query)
    rows = result.all()

    records: list[R] = [row_mapper(record, email) for record, email in rows]
    return records, total, calculate_total_pages(total, per_page)


def _to_counter_record_response(
    record: CounterRecord, email: str
) -> CounterRecordResponse:
    return CounterRecordResponse(
        id=record.id,
        user_email=email,
        value_before=record.value_before,
        value_after=record.value_after,
        created_at=record.created_at,
    )


def _to_sum_record_response(record: SumRecord, email: str) -> SumRecordResponse:
    return SumRecordResponse(
        id=record.id,
        user_email=email,
        a=record.a,
        b=record.b,
        result=record.result,
        created_at=record.created_at,
    )


@router.get("/counter", response_model=PaginatedCounterRecords)
async def get_counter_records(
    page: int = Query(1, ge=1),
    per_page: int = Query(10, ge=1, le=100),
    db: AsyncSession = Depends(get_db),
    _current_user: User = Depends(require_permission(Permission.VIEW_AUDIT)),
) -> PaginatedCounterRecords:
    """Get paginated counter action records."""
    records, total, _ = await paginate_with_user_email(
        db, CounterRecord, page, per_page, _to_counter_record_response
    )
    return create_paginated_response(records, total, page, per_page)


@router.get("/sum", response_model=PaginatedSumRecords)
async def get_sum_records(
    page: int = Query(1, ge=1),
    per_page: int = Query(10, ge=1, le=100),
    db: AsyncSession = Depends(get_db),
    _current_user: User = Depends(require_permission(Permission.VIEW_AUDIT)),
) -> PaginatedSumRecords:
    """Get paginated sum action records."""
    records, total, _ = await paginate_with_user_email(
        db, SumRecord, page, per_page, _to_sum_record_response
    )
    return create_paginated_response(records, total, page, per_page)


@router.get("/random-jobs", response_model=list[RandomNumberOutcomeResponse])
async def get_random_job_outcomes(
    db: AsyncSession = Depends(get_db),
    _current_user: User = Depends(require_permission(Permission.VIEW_AUDIT)),
) -> list[RandomNumberOutcomeResponse]:
    """Get all random number job outcomes, newest first."""
    # Explicit join to avoid N+1 query
    query = (
        select(RandomNumberOutcome, User.email)
        .join(User, RandomNumberOutcome.triggered_by_user_id == User.id)
        .order_by(desc(RandomNumberOutcome.created_at))
    )
    result = await db.execute(query)
    rows = result.all()

    return [
        RandomNumberOutcomeResponse(
            id=outcome.id,
            job_id=outcome.job_id,
            triggered_by_user_id=outcome.triggered_by_user_id,
            triggered_by_email=email,
            value=outcome.value,
            duration_ms=outcome.duration_ms,
            status=outcome.status,
            created_at=outcome.created_at,
        )
        for outcome, email in rows
    ]