package approval

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"time"

	"git.faercol.me/faercol/polyculeconnect/polyculeconnect/config"
	"git.faercol.me/faercol/polyculeconnect/polyculeconnect/services/db"
)

const (
	insertRememberApproval = `INSERT INTO stored_approvals (email, client_id, expiry) VALUES (?, ?, ?)`
	getApproval            = `SELECT expiry FROM stored_approvalts WHERE email = ? AND client_id = ?`
	dbTimeout              = 30 * time.Second
	approvalExpiration     = 30 * 24 * time.Hour
)

type Claim struct {
	Email    string
	ClientID string
}

type ApprovalService interface {
	Remember(ctx context.Context, claim Claim) error
	IsRemembered(ctx context.Context, claim Claim) (bool, error)
}

type concreteApprovalService struct {
	conf *config.AppConfig
}

func (cas *concreteApprovalService) Remember(ctx context.Context, claim Claim) error {
	db, err := db.Connect(cas.conf)
	if err != nil {
		return fmt.Errorf("failed to connect to db: %w", err)
	}

	queryCtx, cancel := context.WithTimeout(ctx, dbTimeout)
	defer cancel()

	tx, err := db.BeginTx(queryCtx, nil)
	if err != nil {
		return fmt.Errorf("failed to begin transaction: %w", err)
	}

	expiry := time.Now().UTC().Add(approvalExpiration)
	_, err = tx.Exec(insertRememberApproval, claim.Email, claim.ClientID, expiry)
	if err != nil {
		return fmt.Errorf("failed to insert approval in DB: %w", err)
	}

	if err := tx.Commit(); err != nil {
		return fmt.Errorf("failed to commit transaction: %w", err)
	}
	return nil
}

func (cas *concreteApprovalService) IsRemembered(ctx context.Context, claim Claim) (bool, error) {
	db, err := db.Connect(cas.conf)
	if err != nil {
		return false, fmt.Errorf("failed to connect to db: %w", err)
	}

	row := db.QueryRow(getApproval, claim.Email, claim.ClientID)
	var expiry time.Time
	if err := row.Scan(&expiry); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return false, nil
		}
		return false, fmt.Errorf("failed to run query: %w", err)
	}

	return time.Now().UTC().Before(expiry), nil
}

func New(conf *config.AppConfig) ApprovalService {
	return &concreteApprovalService{conf: conf}
}