package accountapiimp

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"go.mongodb.org/mongo-driver/v2/bson"
)

// TestPasswordResetFlowLogic tests the logical flow without database dependencies
func TestPasswordResetFlowLogic(t *testing.T) {
	t.Run("CompleteFlow", func(t *testing.T) {
		// Step 1: User requests password reset
		userEmail := "test@example.com"
		assert.NotEmpty(t, userEmail, "Email should not be empty")
		assert.Contains(t, userEmail, "@", "Email should contain @ symbol")

		// Step 2: System generates reset token
		originalToken := ""
		resetToken := "generated-reset-token-123"
		assert.NotEmpty(t, resetToken, "Reset token should be generated")
		assert.NotEqual(t, originalToken, resetToken, "Reset token should be different from empty")

		// Step 3: User clicks reset link with token
		userID := bson.NewObjectID()
		assert.NotEqual(t, bson.NilObjectID, userID, "User ID should be valid")

		// Step 4: System validates token and updates password
		storedToken := resetToken
		providedToken := resetToken
		tokenValid := storedToken == providedToken
		assert.True(t, tokenValid, "Token should be valid")

		// Step 5: Password gets updated and token cleared
		oldPassword := "old-password"
		newPassword := "new-password-123!"
		clearedToken := ""

		assert.NotEqual(t, oldPassword, newPassword, "Password should be changed")
		assert.Empty(t, clearedToken, "Token should be cleared after use")
		assert.NotEqual(t, storedToken, clearedToken, "Token should be different after clearing")
	})

	t.Run("TokenSecurity", func(t *testing.T) {
		// Test that tokens are single-use
		originalToken := "valid-token-123"
		usedToken := "" // After use, token should be cleared

		assert.NotEmpty(t, originalToken, "Original token should exist")
		assert.Empty(t, usedToken, "Used token should be cleared")
		assert.NotEqual(t, originalToken, usedToken, "Token should be cleared after use")

		// Test that different tokens are not equal
		token1 := "token-123"
		token2 := "token-456"
		assert.NotEqual(t, token1, token2, "Different tokens should not be equal")
	})
}

// TestPasswordValidationLogic tests password complexity requirements
func TestPasswordValidationLogic(t *testing.T) {
	t.Run("ValidPasswords", func(t *testing.T) {
		validPasswords := []string{
			"Password123!",
			"MySecurePass1@",
			"ComplexP@ssw0rd",
		}

		for _, password := range validPasswords {
			t.Run(password, func(t *testing.T) {
				// Test minimum length
				assert.True(t, len(password) >= 8, "Password should be at least 8 characters")

				// Test for at least one digit
				hasDigit := false
				for _, char := range password {
					if char >= '0' && char <= '9' {
						hasDigit = true
						break
					}
				}
				assert.True(t, hasDigit, "Password should contain at least one digit")

				// Test for at least one uppercase letter
				hasUpper := false
				for _, char := range password {
					if char >= 'A' && char <= 'Z' {
						hasUpper = true
						break
					}
				}
				assert.True(t, hasUpper, "Password should contain at least one uppercase letter")

				// Test for at least one lowercase letter
				hasLower := false
				for _, char := range password {
					if char >= 'a' && char <= 'z' {
						hasLower = true
						break
					}
				}
				assert.True(t, hasLower, "Password should contain at least one lowercase letter")

				// Test for at least one special character
				hasSpecial := false
				specialChars := "!@#$%^&*()_+-=[]{}|;:,.<>?"
				for _, char := range password {
					for _, special := range specialChars {
						if char == special {
							hasSpecial = true
							break
						}
					}
					if hasSpecial {
						break
					}
				}
				assert.True(t, hasSpecial, "Password should contain at least one special character")
			})
		}
	})

	t.Run("InvalidPasswords", func(t *testing.T) {
		invalidPasswords := []string{
			"",              // Empty
			"short",         // Too short
			"nouppercase1!", // No uppercase
			"NOLOWERCASE1!", // No lowercase
			"NoNumbers!",    // No numbers
			"NoSpecial1",    // No special characters
		}

		for _, password := range invalidPasswords {
			t.Run(password, func(t *testing.T) {
				// Test that invalid passwords fail at least one requirement
				isValid := true

				// Check length
				if len(password) < 8 {
					isValid = false
				}

				// Check for digit
				hasDigit := false
				for _, char := range password {
					if char >= '0' && char <= '9' {
						hasDigit = true
						break
					}
				}
				if !hasDigit {
					isValid = false
				}

				// Check for uppercase
				hasUpper := false
				for _, char := range password {
					if char >= 'A' && char <= 'Z' {
						hasUpper = true
						break
					}
				}
				if !hasUpper {
					isValid = false
				}

				// Check for lowercase
				hasLower := false
				for _, char := range password {
					if char >= 'a' && char <= 'z' {
						hasLower = true
						break
					}
				}
				if !hasLower {
					isValid = false
				}

				// Check for special character
				hasSpecial := false
				specialChars := "!@#$%^&*()_+-=[]{}|;:,.<>?"
				for _, char := range password {
					for _, special := range specialChars {
						if char == special {
							hasSpecial = true
							break
						}
					}
					if hasSpecial {
						break
					}
				}
				if !hasSpecial {
					isValid = false
				}

				assert.False(t, isValid, "Invalid password should fail validation")
			})
		}
	})
}

// TestEmailValidationLogic tests email format validation
func TestEmailValidationLogic(t *testing.T) {
	t.Run("ValidEmails", func(t *testing.T) {
		validEmails := []string{
			"test@example.com",
			"user.name@domain.org",
			"user+tag@example.co.uk",
			"test123@domain.com",
		}

		for _, email := range validEmails {
			t.Run(email, func(t *testing.T) {
				// Basic email validation logic
				hasAt := false
				hasDot := false
				atIndex := -1
				dotIndex := -1

				for i, char := range email {
					if char == '@' {
						hasAt = true
						atIndex = i
					}
					if char == '.' {
						hasDot = true
						dotIndex = i
					}
				}

				assert.True(t, hasAt, "Valid email should contain @")
				assert.True(t, hasDot, "Valid email should contain .")
				assert.True(t, atIndex > 0, "Valid email should have @ not at start")
				assert.True(t, dotIndex > atIndex, "Valid email should have . after @")
				assert.True(t, len(email) > atIndex+1, "Valid email should have domain after @")
			})
		}
	})

	t.Run("InvalidEmails", func(t *testing.T) {
		invalidEmails := []string{
			"",              // Empty
			"noat.com",      // No @
			"test@nodot",    // No .
			"@nodomain.com", // No local part
			"test@.com",     // No domain
			"test.com@",     // No domain after @
		}

		for _, email := range invalidEmails {
			t.Run(email, func(t *testing.T) {
				// Basic email validation logic
				hasAt := false
				hasDot := false
				atIndex := -1
				dotIndex := -1

				for i, char := range email {
					if char == '@' {
						hasAt = true
						atIndex = i
					}
					if char == '.' {
						hasDot = true
						dotIndex = i
					}
				}

				// Invalid emails should fail at least one requirement
				domainAfterDot := len(email) > dotIndex+1
				domainAfterAt := len(email) > atIndex+1
				isValid := hasAt && hasDot && atIndex > 0 && dotIndex > atIndex && domainAfterAt && domainAfterDot && (dotIndex-atIndex) > 1
				assert.False(t, isValid, "Invalid email should fail validation")
			})
		}
	})
}