package handlers

import (
	"authorization/models"
	"bytes"
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestInitAuthService(t *testing.T) {
	// Test that InitAuthService can be called
	// It may panic if DB is not available, which is expected behavior
	defer func() {
		if r := recover(); r != nil {
			t.Logf("InitAuthService panicked (expected without DB): %v", r)
			// This is acceptable - the function requires a DB connection
		}
	}()

	// This will initialize with whatever DB is available
	// If DB is nil, it will panic which is caught above
	InitAuthService()

	t.Log("InitAuthService completed successfully")
}

func TestAuthorizeHandlerNoJWTClaims(t *testing.T) {
	// Setup
	req := httptest.NewRequest("POST", AuthCheckEndpoint, nil)
	w := httptest.NewRecorder()

	// Execute
	AuthorizeHandler(w, req)

	// Assert
	if w.Code != http.StatusUnauthorized {
		t.Errorf(ExpectedStatusMessage, http.StatusUnauthorized, w.Code)
	}
}

func TestAuthorizeHandlerInvalidJSON(t *testing.T) {
	// Setup - no need to init service, we're testing JSON parsing before auth
	claims := &models.Claims{
		UsersID: "user123",
		RoleID:  models.RoleIDs{1},
	}

	req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBufferString("invalid json"))
	ctx := context.WithValue(req.Context(), models.ContextKey("claims"), claims)
	req = req.WithContext(ctx)
	w := httptest.NewRecorder()

	// Execute
	AuthorizeHandler(w, req)

	// Assert
	if w.Code != http.StatusBadRequest {
		t.Errorf(ExpectedStatusMessage, http.StatusBadRequest, w.Code)
	}
}

func TestAuthorizeHandlerMissingRequiredFields(t *testing.T) {
	testCases := []struct {
		name    string
		payload models.AuthorizationContext
	}{
		{
			name:    "Missing UserID",
			payload: models.AuthorizationContext{Resource: "document", Action: "read"},
		},
		{
			name:    "Missing Resource",
			payload: models.AuthorizationContext{UsersID: "user123", Action: "read"},
		},
		{
			name:    "Missing Action",
			payload: models.AuthorizationContext{UsersID: "user123", Resource: "document"},
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			claims := &models.Claims{
				UsersID: "user123",
				RoleID:  models.RoleIDs{1},
			}

			body, _ := json.Marshal(tc.payload)
			req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBuffer(body))
			ctx := context.WithValue(req.Context(), models.ContextKey("claims"), claims)
			req = req.WithContext(ctx)
			w := httptest.NewRecorder()

			AuthorizeHandler(w, req)

			if w.Code != http.StatusBadRequest {
				t.Errorf(ExpectedStatusMessage, http.StatusBadRequest, w.Code)
			}
		})
	}
}

func TestAuthorizeHandlerUserIDMismatch(t *testing.T) {
	// Setup
	claims := &models.Claims{
		UsersID: "user123",
		RoleID:  models.RoleIDs{1},
	}

	payload := models.AuthorizationContext{
		UsersID:  "differentUser",
		Resource: "document",
		Action:   "read",
	}

	body, _ := json.Marshal(payload)
	req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBuffer(body))
	ctx := context.WithValue(req.Context(), models.ContextKey("claims"), claims)
	req = req.WithContext(ctx)
	w := httptest.NewRecorder()

	// Execute
	AuthorizeHandler(w, req)

	// Assert
	if w.Code != http.StatusForbidden {
		t.Errorf(ExpectedStatusMessage, http.StatusForbidden, w.Code)
	}
}

func TestAuthorizeHandlerNilMaps(t *testing.T) {
	// Test that nil maps don't cause additional panics beyond missing authService
	claims := &models.Claims{
		UsersID: "user123",
		RoleID:  models.RoleIDs{1},
	}

	payload := models.AuthorizationContext{
		UsersID:      "user123",
		Resource:     "document",
		Action:       "read",
		ResourceData: nil, // nil map
		Environment:  nil, // nil map
	}

	body, _ := json.Marshal(payload)
	req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBuffer(body))
	ctx := context.WithValue(req.Context(), models.ContextKey("claims"), claims)
	req = req.WithContext(ctx)
	w := httptest.NewRecorder()

	// Execute - may panic if authService is nil (which is expected without DB)
	defer func() {
		if r := recover(); r != nil {
			t.Logf("Handler panicked (expected without authService): %v", r)
		}
	}()

	AuthorizeHandler(w, req)

	// Verify handler set a response code if it didn't panic
	if w.Code != 0 {
		t.Logf("Handler completed with status code: %d", w.Code)
	}
}

// Additional comprehensive test cases

func TestAuthorizeHandlerEmptyUserID(t *testing.T) {
	claims := &models.Claims{
		UsersID: "user123",
		RoleID:  models.RoleIDs{1},
	}

	payload := models.AuthorizationContext{
		UsersID:  "",
		Resource: "document",
		Action:   "read",
	}

	body, _ := json.Marshal(payload)
	req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBuffer(body))
	ctx := context.WithValue(req.Context(), models.ContextKey("claims"), claims)
	req = req.WithContext(ctx)
	w := httptest.NewRecorder()

	AuthorizeHandler(w, req)

	if w.Code != http.StatusBadRequest {
		t.Errorf("Expected status %d for empty UserID, got %d", http.StatusBadRequest, w.Code)
	}
}

func TestAuthorizeHandlerEmptyResource(t *testing.T) {
	claims := &models.Claims{
		UsersID: "user123",
		RoleID:  models.RoleIDs{1},
	}

	payload := models.AuthorizationContext{
		UsersID:  "user123",
		Resource: "",
		Action:   "read",
	}

	body, _ := json.Marshal(payload)
	req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBuffer(body))
	ctx := context.WithValue(req.Context(), models.ContextKey("claims"), claims)
	req = req.WithContext(ctx)
	w := httptest.NewRecorder()

	AuthorizeHandler(w, req)

	if w.Code != http.StatusBadRequest {
		t.Errorf("Expected status %d for empty Resource, got %d", http.StatusBadRequest, w.Code)
	}
}

func TestAuthorizeHandlerEmptyAction(t *testing.T) {
	claims := &models.Claims{
		UsersID: "user123",
		RoleID:  models.RoleIDs{1},
	}

	payload := models.AuthorizationContext{
		UsersID:  "user123",
		Resource: "document",
		Action:   "",
	}

	body, _ := json.Marshal(payload)
	req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBuffer(body))
	ctx := context.WithValue(req.Context(), models.ContextKey("claims"), claims)
	req = req.WithContext(ctx)
	w := httptest.NewRecorder()

	AuthorizeHandler(w, req)

	if w.Code != http.StatusBadRequest {
		t.Errorf("Expected status %d for empty Action, got %d", http.StatusBadRequest, w.Code)
	}
}

func TestAuthorizeHandlerInvalidClaimsType(t *testing.T) {
	req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBufferString(`{"userId":"user123","resource":"doc","action":"read"}`))

	// Set claims as wrong type
	ctx := context.WithValue(req.Context(), models.ContextKey("claims"), "invalid_claims_type")
	req = req.WithContext(ctx)
	w := httptest.NewRecorder()

	AuthorizeHandler(w, req)

	if w.Code != http.StatusUnauthorized {
		t.Errorf("Expected status %d for invalid claims type, got %d", http.StatusUnauthorized, w.Code)
	}
}

func TestAuthorizeHandlerMalformedJSON(t *testing.T) {
	claims := &models.Claims{
		UsersID: "user123",
		RoleID:  models.RoleIDs{1},
	}

	testCases := []struct {
		name    string
		payload string
	}{
		{"Incomplete JSON", `{"userId":"user123","resource":"doc"`},
		{"Invalid quotes", `{userId:"user123"}`},
		{"Trailing comma", `{"userId":"user123",}`},
		{"Just whitespace", `   `},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBufferString(tc.payload))
			ctx := context.WithValue(req.Context(), models.ContextKey("claims"), claims)
			req = req.WithContext(ctx)
			w := httptest.NewRecorder()

			AuthorizeHandler(w, req)

			if w.Code != http.StatusBadRequest {
				t.Errorf("Expected status %d for malformed JSON, got %d", http.StatusBadRequest, w.Code)
			}
		})
	}
}

func TestAuthorizeHandlerSpecialCharactersInFields(t *testing.T) {
	testCases := []struct {
		name     string
		userID   string
		resource string
		action   string
	}{
		{"Special chars in resource", "user123", "document/file-name_v1.2", "read"},
		{"Unicode in resource", "user123", "文档", "read"},
		{"Spaces in action", "user123", "document", "read write"},
		{"Special chars in userID", "user-123_test", "document", "read"},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			payload := models.AuthorizationContext{
				UsersID:  tc.userID,
				Resource: tc.resource,
				Action:   tc.action,
			}

			body, _ := json.Marshal(payload)
			req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBuffer(body))

			// Update claims to match userID
			testClaims := &models.Claims{
				UsersID: tc.userID,
				RoleID:  models.RoleIDs{1},
			}
			ctx := context.WithValue(req.Context(), models.ContextKey("claims"), testClaims)
			req = req.WithContext(ctx)
			w := httptest.NewRecorder()

			// May panic if authService is nil (expected without DB)
			defer func() {
				if r := recover(); r != nil {
					t.Logf("Handler panicked (expected without authService): %v", r)
				}
			}()

			AuthorizeHandler(w, req)

			// If it didn't panic, verify it set a response status
			if w.Code != 0 {
				t.Logf("Handler completed with status: %d", w.Code)
			}
		})
	}
}
func TestAuthorizeHandlerWithResourceData(t *testing.T) {
	// Test that ResourceData is properly passed through to authorization
	claims := &models.Claims{
		UsersID: "user123",
		RoleID:  models.RoleIDs{1},
	}

	payload := models.AuthorizationContext{
		UsersID:  "user123",
		Resource: "personnel",
		Action:   "assign_role",
		ResourceData: map[string]string{
			"region": "01",
		},
	}

	body, _ := json.Marshal(payload)
	req := httptest.NewRequest("POST", AuthCheckEndpoint, bytes.NewBuffer(body))
	ctx := context.WithValue(req.Context(), models.ContextKey("claims"), claims)
	req = req.WithContext(ctx)
	w := httptest.NewRecorder()

	defer func() {
		if r := recover(); r != nil {
			t.Logf("Handler panicked (expected without DB): %v", r)
		}
	}()

	AuthorizeHandler(w, req)

	// ResourceData should not cause any parsing errors
	if w.Code == http.StatusBadRequest {
		t.Errorf("Handler returned bad request with valid ResourceData")
	}
}

func TestCollectClaimRolesIncludesProjectRoles(t *testing.T) {
	claims := &models.Claims{
		RoleID: models.RoleIDs{2},
		Projects: []models.ProjectClaim{
			{ProjectID: 7, RoleID: models.RoleIDs{2, 4}},
			{ProjectID: 8, RoleID: models.RoleIDs{5}},
		},
	}

	roles := collectClaimRoles(claims)
	if len(roles) != 3 {
		t.Fatalf("expected 3 unique roles, got %d (%v)", len(roles), roles)
	}

	if roles[0] != 2 || roles[1] != 4 || roles[2] != 5 {
		t.Fatalf("unexpected role order/content: %v", roles)
	}
}

func TestIntersectRolesReturnsOverlap(t *testing.T) {
	requested := []int{4, 9, 4, 2}
	available := []int{2, 4, 5}

	result := intersectRoles(requested, available)
	if len(result) != 2 {
		t.Fatalf("expected 2 matching roles, got %d (%v)", len(result), result)
	}

	if result[0] != 4 || result[1] != 2 {
		t.Fatalf("unexpected intersection result: %v", result)
	}
}

func TestCollectRequestedRolesFromArray(t *testing.T) {
	ctx := &models.AuthorizationContext{
		RoleIDs: []int{3, 7},
		RoleID:  3,
	}

	result := collectRequestedRoles(ctx)
	if len(result) != 2 {
		t.Fatalf("expected 2 requested roles, got %d (%v)", len(result), result)
	}

	if result[0] != 3 || result[1] != 7 {
		t.Fatalf("unexpected requested roles: %v", result)
	}
}

func TestCollectClaimRolesIncludesAdditionalRoles(t *testing.T) {
	claims := &models.Claims{
		RoleID:           models.RoleIDs{30},
		AdditionalRoleID: models.RoleIDs{4, 5, 30},
	}

	roles := collectClaimRoles(claims)
	if len(roles) != 3 {
		t.Fatalf("expected 3 unique roles, got %d (%v)", len(roles), roles)
	}

	if roles[0] != 30 || roles[1] != 4 || roles[2] != 5 {
		t.Fatalf("unexpected role order/content: %v", roles)
	}
}

func TestBuildRoleCandidates_PrioritizesRequestedThenFallsBackToClaims(t *testing.T) {
	requested := []int{30}
	claimRoles := []int{30, 44, 52}

	result := buildRoleCandidates(requested, claimRoles)
	if len(result) != 3 {
		t.Fatalf("expected 3 candidate roles, got %d (%v)", len(result), result)
	}

	if result[0] != 30 || result[1] != 44 || result[2] != 52 {
		t.Fatalf("unexpected candidate role order/content: %v", result)
	}
}

func TestBuildRoleCandidates_ReturnsNilWhenRequestedNotInClaims(t *testing.T) {
	requested := []int{999}
	claimRoles := []int{30, 44}

	result := buildRoleCandidates(requested, claimRoles)
	if len(result) != 0 {
		t.Fatalf("expected no candidates for mismatched requested role, got %v", result)
	}
}