package services

import (
	"context"
	"database/sql"
	"testing"

	"github.com/DATA-DOG/go-sqlmock"
)

func TestNewEmailService(t *testing.T) {
	db, _, err := sqlmock.New()
	if err != nil {
		t.Fatalf("Failed to create mock db: %v", err)
	}
	defer db.Close()

	credsSvc := &CredentialsService{
		DB:    db,
		cache: make(map[string]string),
	}

	service := NewEmailService(db, credsSvc)
	concreteService, ok := service.(*emailServiceImpl)
	if !ok {
		t.Fatal("Expected NewEmailService to return *emailServiceImpl")
	}

	if concreteService == nil {
		t.Error("Expected service, got nil")
	}
	if concreteService.db != db {
		t.Error("Expected db to be set")
	}
	if concreteService.credentialsService != credsSvc {
		t.Error("Expected credentialsService to be set")
	}
}

func TestEmailService_SendTemplateEmail_NoAMQPURL(t *testing.T) {
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("Failed to create mock db: %v", err)
	}
	defer db.Close()

	credsSvc := &CredentialsService{
		DB:    db,
		cache: make(map[string]string),
	}

	service := NewEmailService(db, credsSvc)
	ctx := context.Background()

	t.Run("returns error when AMQP URL not configured", func(t *testing.T) {
		// Return empty/null amqp_url
		mock.ExpectQuery("SELECT amqp_url FROM email_settings").
			WillReturnRows(sqlmock.NewRows([]string{"amqp_url"}).AddRow(sql.NullString{Valid: false}))

		err := service.SendTemplateEmail(ctx, "test@example.com", "welcome", map[string]interface{}{"name": "Test"})
		if err == nil {
			t.Error("Expected error for missing AMQP URL, got nil")
		}
		if err.Error() != "AMQP URL not configured in email_settings" {
			t.Errorf("Unexpected error message: %v", err)
		}

		if err := mock.ExpectationsWereMet(); err != nil {
			t.Errorf("Unmet expectations: %v", err)
		}
	})
}

func TestEmailService_SendTemplateEmail_DBError(t *testing.T) {
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("Failed to create mock db: %v", err)
	}
	defer db.Close()

	credsSvc := &CredentialsService{
		DB:    db,
		cache: make(map[string]string),
	}

	service := NewEmailService(db, credsSvc)
	ctx := context.Background()

	t.Run("handles db error gracefully", func(t *testing.T) {
		// Return error on query
		mock.ExpectQuery("SELECT amqp_url FROM email_settings").
			WillReturnError(sql.ErrConnDone)

		// Should still fail due to empty URL after logging error
		err := service.SendTemplateEmail(ctx, "test@example.com", "welcome", nil)
		if err == nil {
			t.Error("Expected error, got nil")
		}

		if err := mock.ExpectationsWereMet(); err != nil {
			t.Errorf("Unmet expectations: %v", err)
		}
	})
}

func TestEmailJob_Struct(t *testing.T) {
	job := EmailJob{
		To:        "user@example.com",
		Template:  "password_reset",
		Variables: map[string]interface{}{"reset_link": "https://example.com/reset"},
	}

	if job.To != "user@example.com" {
		t.Errorf("Expected To='user@example.com', got '%s'", job.To)
	}
	if job.Template != "password_reset" {
		t.Errorf("Expected Template='password_reset', got '%s'", job.Template)
	}
	if job.Variables["reset_link"] != "https://example.com/reset" {
		t.Errorf("Expected reset_link variable to be set")
	}
}