package s3api

import (
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"github.com/seaweedfs/seaweedfs/weed/s3api/s3_constants"
)

// TestCheckGovernanceBypassPermissionResourceGeneration tests that the function
// correctly generates resource paths for the permission check
func TestCheckGovernanceBypassPermissionResourceGeneration(t *testing.T) {
	tests := []struct {
		name         string
		bucket       string
		object       string
		expectedPath string
		description  string
	}{
		{
			name:         "simple_object",
			bucket:       "test-bucket",
			object:       "test-object.txt",
			expectedPath: "test-bucket/test-object.txt",
			description:  "Simple bucket and object should be joined with slash",
		},
		{
			name:         "object_with_leading_slash",
			bucket:       "test-bucket",
			object:       "/test-object.txt",
			expectedPath: "test-bucket/test-object.txt",
			description:  "Leading slash should be trimmed from object name",
		},
		{
			name:         "nested_object",
			bucket:       "test-bucket",
			object:       "/folder/subfolder/test-object.txt",
			expectedPath: "test-bucket/folder/subfolder/test-object.txt",
			description:  "Nested object path should be handled correctly",
		},
		{
			name:         "empty_object",
			bucket:       "test-bucket",
			object:       "",
			expectedPath: "test-bucket/",
			description:  "Empty object should result in bucket with trailing slash",
		},
		{
			name:         "root_object",
			bucket:       "test-bucket",
			object:       "/",
			expectedPath: "test-bucket/",
			description:  "Root object should result in bucket with trailing slash",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Test the resource generation logic used in checkGovernanceBypassPermission
			resource := strings.TrimPrefix(tt.object, "/")
			actualPath := tt.bucket + "/" + resource

			if actualPath != tt.expectedPath {
				t.Errorf("Resource path generation failed. Expected: %s, Got: %s. %s",
					tt.expectedPath, actualPath, tt.description)
			}
		})
	}
}

// TestCheckGovernanceBypassPermissionActionGeneration tests that the function
// correctly generates action strings for IAM checking
func TestCheckGovernanceBypassPermissionActionGeneration(t *testing.T) {
	tests := []struct {
		name                 string
		bucket               string
		object               string
		expectedBypassAction string
		expectedAdminAction  string
		description          string
	}{
		{
			name:                 "bypass_action_generation",
			bucket:               "test-bucket",
			object:               "test-object.txt",
			expectedBypassAction: "BypassGovernanceRetention:test-bucket/test-object.txt",
			expectedAdminAction:  "Admin:test-bucket/test-object.txt",
			description:          "Actions should be properly formatted with resource path",
		},
		{
			name:                 "leading_slash_handling",
			bucket:               "test-bucket",
			object:               "/test-object.txt",
			expectedBypassAction: "BypassGovernanceRetention:test-bucket/test-object.txt",
			expectedAdminAction:  "Admin:test-bucket/test-object.txt",
			description:          "Leading slash should be trimmed in action generation",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Test the action generation logic used in checkGovernanceBypassPermission
			resource := strings.TrimPrefix(tt.object, "/")
			resourcePath := tt.bucket + "/" + resource

			bypassAction := s3_constants.ACTION_BYPASS_GOVERNANCE_RETENTION + ":" + resourcePath
			adminAction := s3_constants.ACTION_ADMIN + ":" + resourcePath

			if bypassAction != tt.expectedBypassAction {
				t.Errorf("Bypass action generation failed. Expected: %s, Got: %s. %s",
					tt.expectedBypassAction, bypassAction, tt.description)
			}

			if adminAction != tt.expectedAdminAction {
				t.Errorf("Admin action generation failed. Expected: %s, Got: %s. %s",
					tt.expectedAdminAction, adminAction, tt.description)
			}
		})
	}
}

// TestCheckGovernanceBypassPermissionErrorHandling tests error handling scenarios
func TestCheckGovernanceBypassPermissionErrorHandling(t *testing.T) {
	// Note: This test demonstrates the expected behavior for different error scenarios
	// without requiring full IAM setup

	tests := []struct {
		name        string
		bucket      string
		object      string
		description string
	}{
		{
			name:        "empty_bucket",
			bucket:      "",
			object:      "test-object.txt",
			description: "Empty bucket should be handled gracefully",
		},
		{
			name:        "special_characters",
			bucket:      "test-bucket",
			object:      "test object with spaces.txt",
			description: "Objects with special characters should be handled",
		},
		{
			name:        "unicode_characters",
			bucket:      "test-bucket",
			object:      "测试文件.txt",
			description: "Objects with unicode characters should be handled",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Test that the function doesn't panic with various inputs
			// This would normally call checkGovernanceBypassPermission
			// but since we don't have a full S3ApiServer setup, we just test
			// that the resource generation logic works without panicking
			resource := strings.TrimPrefix(tt.object, "/")
			resourcePath := tt.bucket + "/" + resource

			// Verify the resource path is generated
			if resourcePath == "" {
				t.Errorf("Resource path should not be empty for test case: %s", tt.description)
			}

			t.Logf("Generated resource path for %s: %s", tt.description, resourcePath)
		})
	}
}

// TestCheckGovernanceBypassPermissionIntegrationBehavior documents the expected behavior
// when integrated with a full IAM system
func TestCheckGovernanceBypassPermissionIntegrationBehavior(t *testing.T) {
	t.Skip("Documentation test - describes expected behavior with full IAM integration")

	// This test documents the expected behavior when checkGovernanceBypassPermission
	// is called with a full IAM system:
	//
	// 1. Function calls s3a.iam.authRequest() with the bypass action
	// 2. If authRequest returns errCode != s3err.ErrNone, function returns false
	// 3. If authRequest succeeds, function checks identity.CanDo() with the bypass action
	// 4. If CanDo() returns true, function returns true
	// 5. If bypass permission fails, function checks admin action with identity.CanDo()
	// 6. If admin action succeeds, function returns true and logs admin access
	// 7. If all checks fail, function returns false
	//
	// The function correctly uses:
	// - s3_constants.ACTION_BYPASS_GOVERNANCE_RETENTION for bypass permission
	// - s3_constants.ACTION_ADMIN for admin permission
	// - Proper resource path generation with bucket/object format
	// - Trimming of leading slashes from object names
}

// TestGovernanceBypassPermission was removed because it tested the old
// insecure behavior of trusting the AmzIsAdmin header. The new implementation
// uses proper IAM authentication instead of relying on client-provided headers.

// Test specifically for users with IAM bypass permission
func TestGovernanceBypassWithIAMPermission(t *testing.T) {
	// This test demonstrates the expected behavior for non-admin users with bypass permission
	// In a real implementation, this would integrate with the full IAM system

	t.Skip("Integration test requires full IAM setup - demonstrates expected behavior")

	// The expected behavior would be:
	// 1. Non-admin user makes request with bypass header
	// 2. checkGovernanceBypassPermission calls s3a.iam.authRequest
	// 3. authRequest validates user identity and checks permissions
	// 4. If user has s3:BypassGovernanceRetention permission, return true
	// 5. Otherwise return false

	// For now, the function correctly returns false for non-admin users
	// when the IAM system doesn't have the user configured with bypass permission
}

func TestGovernancePermissionIntegration(t *testing.T) {
	// Note: This test demonstrates the expected integration behavior
	// In a real implementation, this would require setting up a proper IAM mock
	// with identities that have the bypass governance permission

	t.Skip("Integration test requires full IAM setup - demonstrates expected behavior")

	// This test would verify:
	// 1. User with BypassGovernanceRetention permission can bypass governance
	// 2. User without permission cannot bypass governance
	// 3. Admin users can always bypass governance
	// 4. Anonymous users cannot bypass governance
}

func TestGovernanceBypassHeader(t *testing.T) {
	tests := []struct {
		name           string
		headerValue    string
		expectedResult bool
		description    string
	}{
		{
			name:           "bypass_header_true",
			headerValue:    "true",
			expectedResult: true,
			description:    "Header with 'true' value should enable bypass",
		},
		{
			name:           "bypass_header_false",
			headerValue:    "false",
			expectedResult: false,
			description:    "Header with 'false' value should not enable bypass",
		},
		{
			name:           "bypass_header_empty",
			headerValue:    "",
			expectedResult: false,
			description:    "Empty header should not enable bypass",
		},
		{
			name:           "bypass_header_invalid",
			headerValue:    "invalid",
			expectedResult: false,
			description:    "Invalid header value should not enable bypass",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			req := httptest.NewRequest("DELETE", "/bucket/object", nil)
			if tt.headerValue != "" {
				req.Header.Set("x-amz-bypass-governance-retention", tt.headerValue)
			}

			result := req.Header.Get("x-amz-bypass-governance-retention") == "true"

			if result != tt.expectedResult {
				t.Errorf("bypass header check = %v, want %v. %s", result, tt.expectedResult, tt.description)
			}
		})
	}
}

func TestGovernanceRetentionModeChecking(t *testing.T) {
	tests := []struct {
		name              string
		retentionMode     string
		bypassGovernance  bool
		hasPermission     bool
		expectedError     bool
		expectedErrorType string
		description       string
	}{
		{
			name:              "compliance_mode_cannot_bypass",
			retentionMode:     s3_constants.RetentionModeCompliance,
			bypassGovernance:  true,
			hasPermission:     true,
			expectedError:     true,
			expectedErrorType: "compliance mode",
			description:       "Compliance mode should not be bypassable even with permission",
		},
		{
			name:              "governance_mode_without_bypass",
			retentionMode:     s3_constants.RetentionModeGovernance,
			bypassGovernance:  false,
			hasPermission:     false,
			expectedError:     true,
			expectedErrorType: "governance mode",
			description:       "Governance mode should be blocked without bypass",
		},
		{
			name:              "governance_mode_with_bypass_no_permission",
			retentionMode:     s3_constants.RetentionModeGovernance,
			bypassGovernance:  true,
			hasPermission:     false,
			expectedError:     true,
			expectedErrorType: "permission",
			description:       "Governance mode bypass should fail without permission",
		},
		{
			name:              "governance_mode_with_bypass_and_permission",
			retentionMode:     s3_constants.RetentionModeGovernance,
			bypassGovernance:  true,
			hasPermission:     true,
			expectedError:     false,
			expectedErrorType: "",
			description:       "Governance mode bypass should succeed with permission",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Test validates the logic without actually needing the full implementation
			// This demonstrates the expected behavior patterns

			var hasError bool
			var errorType string

			if tt.retentionMode == s3_constants.RetentionModeCompliance {
				hasError = true
				errorType = "compliance mode"
			} else if tt.retentionMode == s3_constants.RetentionModeGovernance {
				if !tt.bypassGovernance {
					hasError = true
					errorType = "governance mode"
				} else if !tt.hasPermission {
					hasError = true
					errorType = "permission"
				}
			}

			if hasError != tt.expectedError {
				t.Errorf("expected error: %v, got error: %v. %s", tt.expectedError, hasError, tt.description)
			}

			if tt.expectedError && !strings.Contains(errorType, tt.expectedErrorType) {
				t.Errorf("expected error type containing '%s', got '%s'. %s", tt.expectedErrorType, errorType, tt.description)
			}
		})
	}
}

func TestGovernancePermissionActionGeneration(t *testing.T) {
	tests := []struct {
		name           string
		bucket         string
		object         string
		expectedAction string
		description    string
	}{
		{
			name:           "bucket_and_object_action",
			bucket:         "test-bucket",
			object:         "/test-object", // Object has "/" prefix from GetBucketAndObject
			expectedAction: "BypassGovernanceRetention:test-bucket/test-object",
			description:    "Action should be generated correctly for bucket and object",
		},
		{
			name:           "bucket_only_action",
			bucket:         "test-bucket",
			object:         "",
			expectedAction: "BypassGovernanceRetention:test-bucket",
			description:    "Action should be generated correctly for bucket only",
		},
		{
			name:           "nested_object_action",
			bucket:         "test-bucket",
			object:         "/folder/subfolder/object", // Object has "/" prefix from GetBucketAndObject
			expectedAction: "BypassGovernanceRetention:test-bucket/folder/subfolder/object",
			description:    "Action should be generated correctly for nested objects",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			action := s3_constants.ACTION_BYPASS_GOVERNANCE_RETENTION + ":" + tt.bucket + tt.object

			if action != tt.expectedAction {
				t.Errorf("generated action: %s, expected: %s. %s", action, tt.expectedAction, tt.description)
			}
		})
	}
}

// TestGovernancePermissionEndToEnd tests the complete object lock permission flow
func TestGovernancePermissionEndToEnd(t *testing.T) {
	t.Skip("End-to-end testing requires full S3 API server setup - demonstrates expected behavior")

	// This test demonstrates the end-to-end flow that would be tested in a full integration test
	// The checkObjectLockPermissions method is called by:
	// 1. DeleteObjectHandler - when versioning is enabled and object lock is configured
	// 2. DeleteMultipleObjectsHandler - for each object in versioned buckets
	// 3. PutObjectHandler - via checkObjectLockPermissionsForPut for versioned buckets
	// 4. PutObjectRetentionHandler - when setting retention on objects
	//
	// Each handler:
	// - Extracts bypassGovernance from "x-amz-bypass-governance-retention" header
	// - Calls checkObjectLockPermissions with the appropriate parameters
	// - Handles the returned errors appropriately (ErrAccessDenied, etc.)
	//
	// The method integrates with the IAM system through checkGovernanceBypassPermission
	// which validates the s3:BypassGovernanceRetention permission
}

// TestGovernancePermissionHTTPFlow tests the HTTP header processing and method calls
func TestGovernancePermissionHTTPFlow(t *testing.T) {
	tests := []struct {
		name                     string
		headerValue              string
		expectedBypassGovernance bool
	}{
		{
			name:                     "bypass_header_true",
			headerValue:              "true",
			expectedBypassGovernance: true,
		},
		{
			name:                     "bypass_header_false",
			headerValue:              "false",
			expectedBypassGovernance: false,
		},
		{
			name:                     "bypass_header_missing",
			headerValue:              "",
			expectedBypassGovernance: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Create a mock HTTP request
			req, _ := http.NewRequest("DELETE", "/bucket/test-object", nil)
			if tt.headerValue != "" {
				req.Header.Set("x-amz-bypass-governance-retention", tt.headerValue)
			}

			// Test the header processing logic used in handlers
			bypassGovernance := req.Header.Get("x-amz-bypass-governance-retention") == "true"

			if bypassGovernance != tt.expectedBypassGovernance {
				t.Errorf("Expected bypassGovernance to be %v, got %v", tt.expectedBypassGovernance, bypassGovernance)
			}
		})
	}
}

// TestGovernancePermissionMethodCalls tests that the governance permission methods are called correctly
func TestGovernancePermissionMethodCalls(t *testing.T) {
	// Test that demonstrates the method call pattern used in handlers

	// This is the pattern used in DeleteObjectHandler:
	t.Run("delete_object_handler_pattern", func(t *testing.T) {
		req, _ := http.NewRequest("DELETE", "/bucket/test-object", nil)
		req.Header.Set("x-amz-bypass-governance-retention", "true")

		// Extract parameters as done in the handler
		bucket, object := s3_constants.GetBucketAndObject(req)
		versionId := req.URL.Query().Get("versionId")
		bypassGovernance := req.Header.Get("x-amz-bypass-governance-retention") == "true"

		// Verify the parameters are extracted correctly
		// Note: The actual bucket and object extraction depends on the URL structure
		t.Logf("Extracted bucket: %s, object: %s", bucket, object)
		if versionId != "" {
			t.Errorf("Expected versionId to be empty, got %v", versionId)
		}
		if !bypassGovernance {
			t.Errorf("Expected bypassGovernance to be true")
		}
	})

	// This is the pattern used in PutObjectHandler:
	t.Run("put_object_handler_pattern", func(t *testing.T) {
		req, _ := http.NewRequest("PUT", "/bucket/test-object", nil)
		req.Header.Set("x-amz-bypass-governance-retention", "true")

		// Extract parameters as done in the handler
		bucket, object := s3_constants.GetBucketAndObject(req)
		bypassGovernance := req.Header.Get("x-amz-bypass-governance-retention") == "true"
		versioningEnabled := true // Would be determined by isVersioningEnabled(bucket)

		// Verify the parameters are extracted correctly
		// Note: The actual bucket and object extraction depends on the URL structure
		t.Logf("Extracted bucket: %s, object: %s", bucket, object)
		if !bypassGovernance {
			t.Errorf("Expected bypassGovernance to be true")
		}
		if !versioningEnabled {
			t.Errorf("Expected versioningEnabled to be true")
		}
	})
}

// TestGovernanceBypassNotPermittedError tests that ErrGovernanceBypassNotPermitted
// is returned when bypass is requested but the user lacks permission
func TestGovernanceBypassNotPermittedError(t *testing.T) {
	// Test the error constant itself
	if ErrGovernanceBypassNotPermitted == nil {
		t.Error("ErrGovernanceBypassNotPermitted should be defined")
	}

	// Verify the error message
	expectedMessage := "user does not have permission to bypass governance retention"
	if ErrGovernanceBypassNotPermitted.Error() != expectedMessage {
		t.Errorf("expected error message '%s', got '%s'",
			expectedMessage, ErrGovernanceBypassNotPermitted.Error())
	}

	// Test the scenario where this error should be returned
	// This documents the expected behavior when:
	// 1. Object is under governance retention
	// 2. bypassGovernance is true
	// 3. checkGovernanceBypassPermission returns false
	testCases := []struct {
		name             string
		retentionMode    string
		bypassGovernance bool
		hasPermission    bool
		expectedError    error
		description      string
	}{
		{
			name:             "governance_bypass_without_permission",
			retentionMode:    s3_constants.RetentionModeGovernance,
			bypassGovernance: true,
			hasPermission:    false,
			expectedError:    ErrGovernanceBypassNotPermitted,
			description:      "Should return ErrGovernanceBypassNotPermitted when bypass is requested but user lacks permission",
		},
		{
			name:             "governance_bypass_with_permission",
			retentionMode:    s3_constants.RetentionModeGovernance,
			bypassGovernance: true,
			hasPermission:    true,
			expectedError:    nil,
			description:      "Should succeed when bypass is requested and user has permission",
		},
		{
			name:             "governance_no_bypass",
			retentionMode:    s3_constants.RetentionModeGovernance,
			bypassGovernance: false,
			hasPermission:    false,
			expectedError:    ErrGovernanceModeActive,
			description:      "Should return ErrGovernanceModeActive when bypass is not requested",
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			// This test documents the expected behavior pattern
			// The actual checkObjectLockPermissions method implements this logic:
			// if retention.Mode == s3_constants.RetentionModeGovernance {
			//     if !bypassGovernance {
			//         return ErrGovernanceModeActive
			//     }
			//     if !s3a.checkGovernanceBypassPermission(request, bucket, object) {
			//         return ErrGovernanceBypassNotPermitted
			//     }
			// }

			var simulatedError error
			if tc.retentionMode == s3_constants.RetentionModeGovernance {
				if !tc.bypassGovernance {
					simulatedError = ErrGovernanceModeActive
				} else if !tc.hasPermission {
					simulatedError = ErrGovernanceBypassNotPermitted
				}
			}

			if simulatedError != tc.expectedError {
				t.Errorf("expected error %v, got %v. %s", tc.expectedError, simulatedError, tc.description)
			}

			// Verify ErrGovernanceBypassNotPermitted is returned in the right case
			if tc.name == "governance_bypass_without_permission" && simulatedError != ErrGovernanceBypassNotPermitted {
				t.Errorf("Test case should return ErrGovernanceBypassNotPermitted but got %v", simulatedError)
			}
		})
	}
}
