package main

import (
	"context"

	"atlas9.dev/c/core"
	"atlas9.dev/c/core/dbi"
	"atlas9.dev/c/core/iam"
)

type SqliteUserStore struct {
	db dbi.DBI
}

var _ iam.UserStore = (*SqliteUserStore)(nil)

func NewSqliteUserStore(db dbi.DBI) *SqliteUserStore {
	return &SqliteUserStore{db: db}
}

func (s *SqliteUserStore) Save(ctx context.Context, user *iam.User) (bool, error) {
	if user.ID.IsZero() {
		user.ID = core.NewID()
	}

	res, err := s.db.Exec(ctx, `
		INSERT INTO users (id, email, verified) VALUES ($1, $2, $3)
		ON CONFLICT (email) DO NOTHING
	`, user.ID, user.Email, user.Verified)
	if err != nil {
		return false, err
	}

	n, err := res.RowsAffected()
	if err != nil {
		return false, err
	}
	created := n > 0

	if !created {
		// emails are unique, so if there's a conflict on email, fetch the existing ID.
		err = dbi.Get(ctx, s.db, user, `SELECT id, verified FROM users WHERE email = $1`, user.Email)
	}

	return created, err
}

func (s *SqliteUserStore) GetByEmail(ctx context.Context, email string) (*iam.User, error) {
	var user iam.User
	err := dbi.Get(ctx, s.db, &user, `SELECT id, email, verified FROM users WHERE email = $1`, email)
	return &user, err
}

func (s *SqliteUserStore) Get(ctx context.Context, id core.ID) (*iam.User, error) {
	var user iam.User
	err := dbi.Get(ctx, s.db, &user, `SELECT id, email, verified FROM users WHERE id = $1`, id)
	return &user, err
}

func (s *SqliteUserStore) Verify(ctx context.Context, id core.ID) error {
	_, err := s.db.Exec(ctx, `UPDATE users SET verified = true WHERE id = $1`, id)
	return err
}

func (s *SqliteUserStore) List(ctx context.Context, page core.PageReq) (core.Page[iam.User], error) {
	limit := page.Limit
	if limit <= 0 {
		limit = 100
	}
	rows, err := s.db.Query(ctx, `
		SELECT id, email, verified FROM users
		WHERE id > $1 ORDER BY id LIMIT $2
	`, page.Cursor, limit)
	if err != nil {
		return core.Page[iam.User]{}, err
	}
	defer rows.Close()

	var items []iam.User
	for rows.Next() {
		var u iam.User
		if err := rows.Scan(&u.ID, &u.Email, &u.Verified); err != nil {
			return core.Page[iam.User]{}, err
		}
		items = append(items, u)
	}
	if err := rows.Err(); err != nil {
		return core.Page[iam.User]{}, err
	}
	var cursor string
	if len(items) == limit {
		cursor = items[limit-1].ID.String()
	}
	return core.Page[iam.User]{Items: items, Cursor: cursor}, nil
}