package tenancy

import (
	"database/sql"
	"regexp"
	"strings"

	"quyun/v2/app/errorx"

	"github.com/gofiber/fiber/v3"
	"github.com/google/uuid"
)

const (
	LocalTenantCode = "tenant_code"
	LocalTenantID   = "tenant_id"
	LocalTenantUUID = "tenant_uuid"
)

var tenantCodeRe = regexp.MustCompile(`^[a-z0-9_-]+$`)

type Tenant struct {
	ID   int64
	Code string
	UUID uuid.UUID
}

func ResolveTenant(c fiber.Ctx, db *sql.DB) (*Tenant, error) {
	raw := strings.TrimSpace(c.Params("tenant_code"))
	code := strings.ToLower(raw)
	if code == "" || !tenantCodeRe.MatchString(code) {
		return nil, errorx.ErrInvalidParameter.WithMsg("invalid tenant_code")
	}

	var (
		id         int64
		tenantUUID uuid.UUID
		status     int16
	)
	err := db.QueryRowContext(
		c.Context(),
		`SELECT id, tenant_uuid, status FROM tenants WHERE lower(tenant_code) = $1 LIMIT 1`,
		code,
	).Scan(&id, &tenantUUID, &status)
	if err != nil {
		if err == sql.ErrNoRows {
			return nil, fiber.ErrNotFound
		}
		return nil, errorx.ErrDatabaseError.WithMsg("database error").WithParams(err.Error())
	}

	// status: 0 enabled (by default)
	if status != 0 {
		return nil, fiber.ErrNotFound
	}

	return &Tenant{ID: id, Code: code, UUID: tenantUUID}, nil
}

func Middleware(db *sql.DB) fiber.Handler {
	return func(c fiber.Ctx) error {
		tenant, err := ResolveTenant(c, db)
		if err != nil {
			return err
		}
		c.Locals(LocalTenantCode, tenant.Code)
		c.Locals(LocalTenantID, tenant.ID)
		c.Locals(LocalTenantUUID, tenant.UUID.String())
		return c.Next()
	}
}