"""API routes for authentication — register, login, refresh, profile."""

import logging

from fastapi import APIRouter, Depends, HTTPException, status
from pydantic import BaseModel, Field, EmailStr
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.db import get_db
from app.db.models import User
from app.services.auth import (
    hash_password,
    verify_password,
    create_token_pair,
    decode_token,
    get_current_user,
    TokenPair,
)

logger = logging.getLogger(__name__)

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


# ── Request / Response models ─────────────────────────────────────────


class RegisterRequest(BaseModel):
    username: str = Field(..., min_length=3, max_length=64)
    email: str = Field(..., max_length=256)
    password: str = Field(..., min_length=8, max_length=128)
    display_name: str | None = None


class LoginRequest(BaseModel):
    username: str
    password: str


class RefreshRequest(BaseModel):
    refresh_token: str


class UserResponse(BaseModel):
    id: str
    username: str
    email: str
    display_name: str | None
    role: str
    is_active: bool
    created_at: str


class AuthResponse(BaseModel):
    user: UserResponse
    tokens: TokenPair


# ── Routes ────────────────────────────────────────────────────────────


@router.post(
    "/register",
    response_model=AuthResponse,
    status_code=status.HTTP_201_CREATED,
    summary="Register a new user",
)
async def register(body: RegisterRequest, db: AsyncSession = Depends(get_db)):
    # Check for existing username
    result = await db.execute(select(User).where(User.username == body.username))
    if result.scalar_one_or_none():
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail="Username already taken",
        )

    # Check for existing email
    result = await db.execute(select(User).where(User.email == body.email))
    if result.scalar_one_or_none():
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail="Email already registered",
        )

    user = User(
        username=body.username,
        email=body.email,
        hashed_password=hash_password(body.password),
        display_name=body.display_name or body.username,
        role="analyst",  # Default role
    )
    db.add(user)
    await db.flush()

    tokens = create_token_pair(user.id, user.role)

    logger.info(f"New user registered: {user.username} ({user.id})")

    return AuthResponse(
        user=UserResponse(
            id=user.id,
            username=user.username,
            email=user.email,
            display_name=user.display_name,
            role=user.role,
            is_active=user.is_active,
            created_at=user.created_at.isoformat(),
        ),
        tokens=tokens,
    )


@router.post(
    "/login",
    response_model=AuthResponse,
    summary="Login with username and password",
)
async def login(body: LoginRequest, db: AsyncSession = Depends(get_db)):
    result = await db.execute(select(User).where(User.username == body.username))
    user = result.scalar_one_or_none()

    if not user or not user.hashed_password:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid username or password",
        )

    if not verify_password(body.password, user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid username or password",
        )

    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Account is disabled",
        )

    tokens = create_token_pair(user.id, user.role)

    return AuthResponse(
        user=UserResponse(
            id=user.id,
            username=user.username,
            email=user.email,
            display_name=user.display_name,
            role=user.role,
            is_active=user.is_active,
            created_at=user.created_at.isoformat(),
        ),
        tokens=tokens,
    )


@router.post(
    "/refresh",
    response_model=TokenPair,
    summary="Refresh access token",
)
async def refresh_token(body: RefreshRequest, db: AsyncSession = Depends(get_db)):
    token_data = decode_token(body.refresh_token)

    if token_data.type != "refresh":
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid token type — use refresh token",
        )

    result = await db.execute(select(User).where(User.id == token_data.sub))
    user = result.scalar_one_or_none()

    if not user or not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid user",
        )

    return create_token_pair(user.id, user.role)


@router.get(
    "/me",
    response_model=UserResponse,
    summary="Get current user profile",
)
async def get_profile(user: User = Depends(get_current_user)):
    return UserResponse(
        id=user.id,
        username=user.username,
        email=user.email,
        display_name=user.display_name,
        role=user.role,
        is_active=user.is_active,
        created_at=user.created_at.isoformat() if hasattr(user.created_at, 'isoformat') else str(user.created_at),
    )