package tenant

import (
	"context"
	"crypto/rand"
	"database/sql"
	"encoding/hex"
	"time"
)

func (q *Queries) ListAPIKeys(ctx context.Context) ([]APIKey, error) {
	rows, err := q.db.QueryContext(ctx, `SELECT key, name, created_at, last_used_at FROM api_keys ORDER BY created_at DESC`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var keys []APIKey
	for rows.Next() {
		k, err := scanAPIKey(rows)
		if err != nil {
			return nil, err
		}
		keys = append(keys, k)
	}
	return keys, rows.Err()
}

func (q *Queries) CreateAPIKey(ctx context.Context, name string) (*APIKey, error) {
	key, err := generateAPIKey()
	if err != nil {
		return nil, err
	}

	now := time.Now().UTC().Format(time.RFC3339)
	_, err = q.db.ExecContext(ctx, `INSERT INTO api_keys (key, name, created_at) VALUES (?, ?, ?)`, key, name, now)
	if err != nil {
		return nil, err
	}

	return &APIKey{
		Key:       key,
		Name:      name,
		CreatedAt: time.Now().UTC(),
	}, nil
}

func (q *Queries) ValidateAPIKey(ctx context.Context, key string) (bool, error) {
	var dummy int64
	err := q.db.QueryRowContext(ctx, `SELECT 1 FROM api_keys WHERE key = ?`, key).Scan(&dummy)
	if err == sql.ErrNoRows {
		return false, nil
	}
	if err != nil {
		return false, nil
	}

	go func() {
		now := time.Now().UTC().Format(time.RFC3339)
		q.db.ExecContext(ctx, `UPDATE api_keys SET last_used_at = ? WHERE key = ?`, now, key)
	}()

	return true, nil
}

func (q *Queries) DeleteAPIKey(ctx context.Context, key string) error {
	_, err := q.db.ExecContext(ctx, `DELETE FROM api_keys WHERE key = ?`, key)
	return err
}

func scanAPIKey(s scanner) (APIKey, error) {
	var k APIKey
	var createdAt, lastUsedAt sql.NullString

	err := s.Scan(&k.Key, &k.Name, &createdAt, &lastUsedAt)
	if err != nil {
		return k, err
	}

	k.CreatedAt = parseTime(createdAt.String)
	if lastUsedAt.Valid {
		t := parseTime(lastUsedAt.String)
		k.LastUsedAt = &t
	}
	return k, nil
}

func generateAPIKey() (string, error) {
	b := make([]byte, 24)
	if _, err := rand.Read(b); err != nil {
		return "", err
	}
	return "wk_" + hex.EncodeToString(b), nil
}