"""First-run install wizard.

`GET /api/setup/status` is public (the SPA uses it to decide whether to show the wizard). Every
mutating step goes through `require_setup`: it rejects once the instance is configured AND requires
the one-time setup token (printed to the container logs at first boot, carried by the wizard as the
X-Setup-Token header). The wizard steps themselves are added in epic 6c.
"""
from typing import Any

from fastapi import APIRouter, Depends, Header, HTTPException
from pydantic import BaseModel
from sqlalchemy import select
from sqlalchemy.orm import Session

from app import email as email_mod
from app import state, sysconfig
from app.auth import PASSWORD_MIN_LEN
from app.db import get_db
from app.models import User
from app.security import hash_password

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


def require_setup(
    x_setup_token: str | None = Header(default=None),
    db: Session = Depends(get_db),
) -> Session:
    """Gate for setup steps. Returns the db session for the handler to reuse."""
    if state.is_configured(db):
        raise HTTPException(status_code=409, detail="This instance is already set up.")
    if not state.check_setup_token(db, x_setup_token):
        raise HTTPException(status_code=403, detail="Invalid or missing setup token.")
    return db


@router.get("/status")
def setup_status(db: Session = Depends(get_db)) -> dict:
    """Public: whether the instance still needs first-run setup."""
    return {"configured": state.is_configured(db)}


@router.get("/info")
def setup_info(db: Session = Depends(require_setup)) -> dict:
    """Capabilities the wizard adapts to: whether secrets (Google creds, SMTP password) can be
    stored — they need TOKEN_ENCRYPTION_KEY (set in env), so on a box without it the wizard hides
    those steps and the operator stays on email+password only."""
    return {"secrets_manageable": sysconfig.secrets_manageable()}


class SetupAdminIn(BaseModel):
    # Both default to "" so a missing field stays the wizard's own 400 ("Enter a valid email" /
    # password too short) rather than a 422. `password: str` also stops a non-string value from
    # reaching argon2 (which would 500 in len()/hash_password) — it's now a clean 422.
    email: str = ""
    password: str = ""


@router.post("/admin")
def setup_admin(body: SetupAdminIn, db: Session = Depends(require_setup)) -> dict:
    """Create (or update) the first administrator. Active + verified immediately — the operator is
    configuring the instance, so there's no email-verification / approval gate here."""
    email = body.email.strip().lower()
    password = body.password
    if "@" not in email:
        raise HTTPException(status_code=400, detail="Enter a valid email address.")
    if len(password) < PASSWORD_MIN_LEN:
        raise HTTPException(
            status_code=400, detail=f"Password must be at least {PASSWORD_MIN_LEN} characters."
        )
    user = db.execute(select(User).where(User.email == email)).scalar_one_or_none()
    if user is None:
        user = User(email=email, role="admin")
        db.add(user)
    user.password_hash = hash_password(password)
    user.role = "admin"
    user.is_active = True
    user.email_verified = True
    db.commit()
    return {"ok": True, "email": email}


@router.post("/config")
def setup_config(settings_map: dict[str, Any], db: Session = Depends(require_setup)) -> dict:
    """Persist provided DB-backed settings (Google creds, SMTP, quota…). Keys must be in the
    sysconfig registry; empty values are skipped (left at the default). Genuinely dynamic
    key→value map, so it stays a typed dict rather than a fixed model."""
    saved: list[str] = []
    for key, value in settings_map.items():
        if sysconfig.spec(key) is None:
            raise HTTPException(status_code=400, detail=f"Unknown setting: {key}")
        if value is None or value == "":
            continue
        try:
            sysconfig.set_value(db, key, value)
        except (ValueError, RuntimeError) as exc:
            raise HTTPException(status_code=400, detail=str(exc))
        saved.append(key)
    return {"saved": saved}


class SetupTestEmailIn(BaseModel):
    to: str = ""


@router.post("/test-email")
def setup_test_email(body: SetupTestEmailIn, db: Session = Depends(require_setup)) -> dict:
    """Send a test email to confirm the SMTP settings the wizard just saved."""
    to = body.to.strip()
    if "@" not in to:
        raise HTTPException(status_code=400, detail="Enter a valid email address.")
    if not email_mod.send_test(to):
        raise HTTPException(status_code=400, detail="Couldn't send — check the SMTP settings.")
    return {"ok": True}


@router.post("/finish")
def setup_finish(db: Session = Depends(require_setup)) -> dict:
    """Complete setup: require that an admin exists, then mark the instance configured (which
    invalidates the setup token and disables the wizard)."""
    has_admin = db.execute(select(User).where(User.role == "admin")).first() is not None
    if not has_admin:
        raise HTTPException(status_code=400, detail="Create the admin account first.")
    state.mark_configured(db)
    return {"ok": True}
