package core

import (
	"finance/backend/internal/models"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"gorm.io/gorm"
)

// Mock goal for testing
func createTestGoal() *models.Goal {
	return &models.Goal{
		Model:         gorm.Model{ID: 1, CreatedAt: time.Now().Add(-30 * 24 * time.Hour)}, // created 30 days ago
		UserID:        1,
		Name:          "Test Goal",
		TargetAmount:  10000,
		CurrentAmount: 3000,
		Status:        "Active",
		TargetDate:    time.Now().Add(60 * 24 * time.Hour), // due in 60 days
	}
}

// TestCalculateGoalProgress tests the goal progress calculation logic
func TestCalculateGoalProgress(t *testing.T) {
	// Create a test service
	service := &GoalService{}

	// Test with a goal that's on track
	goal := createTestGoal()
	progress, err := service.calculateGoalProgress(goal)

	assert.NoError(t, err)
	assert.NotNil(t, progress)

	// Verify calculations
	assert.Equal(t, int64(7000), progress.AmountRemaining)
	assert.InDelta(t, 30.0, progress.PercentComplete, 0.1)

	// Should have around 60 days remaining (might vary slightly based on test execution time)
	assert.True(t, progress.DaysRemaining > 55 && progress.DaysRemaining <= 61)

	// Test required amounts
	assert.True(t, progress.RequiredPerDay > 0)
	assert.True(t, progress.RequiredPerMonth > 0)

	// Verify on track status - goal is at 30% completion, we're 1/3 through the time period
	// so it should be on track
	assert.True(t, progress.OnTrack)

	// Test with a goal that's behind
	goal.CurrentAmount = 1000 // only 10% complete after 1/3 of the time
	progress, err = service.calculateGoalProgress(goal)

	assert.NoError(t, err)
	assert.NotNil(t, progress)
	assert.False(t, progress.OnTrack)

	// Test with a goal that has no target date
	goal = createTestGoal()
	goal.TargetDate = time.Time{} // zero time
	progress, err = service.calculateGoalProgress(goal)

	assert.NoError(t, err)
	assert.NotNil(t, progress)
	assert.True(t, progress.OnTrack) // should be on track if any progress made
	assert.Equal(t, 0, progress.DaysRemaining)

	// Test with a goal whose target date has passed
	goal = createTestGoal()
	goal.TargetDate = time.Now().Add(-10 * 24 * time.Hour) // 10 days ago
	progress, err = service.calculateGoalProgress(goal)

	assert.NoError(t, err)
	assert.NotNil(t, progress)
	assert.Equal(t, 0, progress.DaysRemaining)

	// Not on track if target amount not reached
	assert.False(t, progress.OnTrack)

	// But should be on track if target amount reached despite date passed
	goal.CurrentAmount = goal.TargetAmount
	progress, err = service.calculateGoalProgress(goal)

	assert.NoError(t, err)
	assert.True(t, progress.OnTrack)
}

// TestUpdateGoalFromTransactions tests updating a goal based on transactions
func TestUpdateGoalFromTransactions(t *testing.T) {
	// This test would need a mock database to be fully implemented
	// Here's a placeholder for when DB mocking is available

	/*
		// Setup a mock DB
		db, mock := setupMockDB(t)
		service := &GoalService{db: db}

		// Setup expectations
		goalID := uint(1)
		userID := uint(1)

		// Expect a query to fetch the goal
		mock.ExpectQuery(`SELECT * FROM "goals" WHERE "id" = ?`).
			WithArgs(goalID).
			WillReturnRows(sqlmock.NewRows([]string{"id", "user_id", "name", "target_amount", "current_amount", "status"}).
				AddRow(goalID, userID, "Test Goal", 10000, 0, "Active"))

		// Expect a query to fetch transactions
		mock.ExpectQuery(`SELECT * FROM "transactions" WHERE "user_id" = ? AND "category" = ?`).
			WithArgs(userID, "Goal:1").
			WillReturnRows(sqlmock.NewRows([]string{"id", "user_id", "amount", "type", "category"}).
				AddRow(1, userID, 500, "Income", "Goal:1").
				AddRow(2, userID, 300, "Income", "Goal:1").
				AddRow(3, userID, 200, "Expense", "Goal:1"))

		// Expect an update to the goal
		mock.ExpectBegin()
		mock.ExpectExec(`UPDATE "goals" SET`).
			WithArgs(600, "Active", goalID). // 500 + 300 - 200 = 600
			WillReturnResult(sqlmock.NewResult(1, 1))
		mock.ExpectCommit()

		// Run the test
		err := service.UpdateGoalFromTransactions(goalID)
		assert.NoError(t, err)
	*/
}