package store

import (
	"context"
	"errors"
	"fmt"
	"time"

	"github.com/jackc/pgx/v5"
)

// PlatformConnection ist die per OAuth hergestellte Verbindung eines
// Accounts zu seinem eigenen Instagram- oder TikTok-Account (siehe
// internal/socialconnect). Anders als asset/finding/extraction NICHT
// append-only — ein abgelaufenes oder erneuertes Token ersetzt das alte,
// eine getrennte Verbindung wird wirklich gelöscht.
type PlatformConnection struct {
	ID             string
	AccountID      string
	Platform       string
	PlatformUserID string
	AccessToken    string
	RefreshToken   string
	ExpiresAt      *time.Time
	ConnectedAt    time.Time
}

// UpsertPlatformConnection legt eine Verbindung an oder ersetzt die
// bestehende für dasselbe Account+Plattform-Paar (z. B. bei erneutem
// Verbinden nach Trennen, oder wenn refresh_token erneuert wurde).
func (s *Store) UpsertPlatformConnection(ctx context.Context, accountID, platform, platformUserID, accessToken, refreshToken string, expiresAt *time.Time) (PlatformConnection, error) {
	var c PlatformConnection
	err := s.Pool.QueryRow(ctx, `
		INSERT INTO platform_connection (account_id, platform, platform_user_id, access_token, refresh_token, expires_at)
		VALUES ($1, $2, $3, $4, $5, $6)
		ON CONFLICT (account_id, platform) DO UPDATE SET
			platform_user_id = EXCLUDED.platform_user_id,
			access_token = EXCLUDED.access_token,
			refresh_token = EXCLUDED.refresh_token,
			expires_at = EXCLUDED.expires_at,
			connected_at = now()
		RETURNING id, account_id, platform, platform_user_id, access_token, refresh_token, expires_at, connected_at
	`, accountID, platform, platformUserID, accessToken, refreshToken, expiresAt).Scan(
		&c.ID, &c.AccountID, &c.Platform, &c.PlatformUserID, &c.AccessToken, &c.RefreshToken, &c.ExpiresAt, &c.ConnectedAt,
	)
	if err != nil {
		return PlatformConnection{}, fmt.Errorf("store: upsert platform connection: %w", err)
	}
	return c, nil
}

// ListPlatformConnectionsForAccount liefert alle Plattform-Verbindungen
// eines Accounts.
func (s *Store) ListPlatformConnectionsForAccount(ctx context.Context, accountID string) ([]PlatformConnection, error) {
	rows, err := s.Pool.Query(ctx, `
		SELECT id, account_id, platform, platform_user_id, access_token, refresh_token, expires_at, connected_at
		FROM platform_connection WHERE account_id = $1 ORDER BY platform
	`, accountID)
	if err != nil {
		return nil, fmt.Errorf("store: list platform connections: %w", err)
	}
	defer rows.Close()

	var out []PlatformConnection
	for rows.Next() {
		var c PlatformConnection
		if err := rows.Scan(&c.ID, &c.AccountID, &c.Platform, &c.PlatformUserID, &c.AccessToken, &c.RefreshToken, &c.ExpiresAt, &c.ConnectedAt); err != nil {
			return nil, fmt.Errorf("store: scan platform connection: %w", err)
		}
		out = append(out, c)
	}
	if err := rows.Err(); err != nil {
		return nil, fmt.Errorf("store: list platform connections: %w", err)
	}
	return out, nil
}

// GetPlatformConnection liest die Verbindung eines Accounts zu einer
// bestimmten Plattform. Liefert ErrNotFound, wenn keine Verbindung
// besteht — der Normalfall, solange der Kunde nichts verbunden hat.
func (s *Store) GetPlatformConnection(ctx context.Context, accountID, platform string) (PlatformConnection, error) {
	var c PlatformConnection
	err := s.Pool.QueryRow(ctx, `
		SELECT id, account_id, platform, platform_user_id, access_token, refresh_token, expires_at, connected_at
		FROM platform_connection WHERE account_id = $1 AND platform = $2
	`, accountID, platform).Scan(
		&c.ID, &c.AccountID, &c.Platform, &c.PlatformUserID, &c.AccessToken, &c.RefreshToken, &c.ExpiresAt, &c.ConnectedAt,
	)
	if errors.Is(err, pgx.ErrNoRows) {
		return PlatformConnection{}, ErrNotFound
	}
	if err != nil {
		return PlatformConnection{}, fmt.Errorf("store: get platform connection: %w", err)
	}
	return c, nil
}

// DeletePlatformConnection trennt eine Plattform-Verbindung.
func (s *Store) DeletePlatformConnection(ctx context.Context, accountID, platform string) error {
	tag, err := s.Pool.Exec(ctx, `DELETE FROM platform_connection WHERE account_id = $1 AND platform = $2`, accountID, platform)
	if err != nil {
		return fmt.Errorf("store: delete platform connection: %w", err)
	}
	if tag.RowsAffected() == 0 {
		return ErrNotFound
	}
	return nil
}