package copilot

import (
	"encoding/json"
	"os"
	"path/filepath"
	"reflect"
	"regexp"
	"testing"
)

// This file is for unit tests. Where relevant, prefer to add e2e tests in e2e/*.test.go instead

func TestClient_HandleToolCallRequest(t *testing.T) {
	t.Run("returns a standardized failure result when a tool is not registered", func(t *testing.T) {
		cliPath := findCLIPathForTest()
		if cliPath == "" {
			t.Skip("CLI not found")
		}

		client := NewClient(&ClientOptions{CLIPath: cliPath})
		t.Cleanup(func() { client.ForceStop() })

		session, err := client.CreateSession(t.Context(), &SessionConfig{
			OnPermissionRequest: PermissionHandler.ApproveAll,
		})
		if err != nil {
			t.Fatalf("Failed to create session: %v", err)
		}

		params := toolCallRequest{
			SessionID:  session.SessionID,
			ToolCallID: "123",
			ToolName:   "missing_tool",
			Arguments:  map[string]any{},
		}
		response, _ := client.handleToolCallRequest(params)

		if response.Result.ResultType != "failure" {
			t.Errorf("Expected resultType to be 'failure', got %q", response.Result.ResultType)
		}

		if response.Result.Error != "tool 'missing_tool' not supported" {
			t.Errorf("Expected error to be \"tool 'missing_tool' not supported\", got %q", response.Result.Error)
		}
	})
}

func TestClient_URLParsing(t *testing.T) {
	t.Run("should parse port-only URL format", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			CLIUrl: "8080",
		})

		if client.actualPort != 8080 {
			t.Errorf("Expected port 8080, got %d", client.actualPort)
		}
		if client.actualHost != "localhost" {
			t.Errorf("Expected host localhost, got %s", client.actualHost)
		}
		if !client.isExternalServer {
			t.Error("Expected isExternalServer to be true")
		}
	})

	t.Run("should parse host:port URL format", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			CLIUrl: "127.0.0.1:9000",
		})

		if client.actualPort != 9000 {
			t.Errorf("Expected port 9000, got %d", client.actualPort)
		}
		if client.actualHost != "127.0.0.1" {
			t.Errorf("Expected host 127.0.0.1, got %s", client.actualHost)
		}
		if !client.isExternalServer {
			t.Error("Expected isExternalServer to be true")
		}
	})

	t.Run("should parse http://host:port URL format", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			CLIUrl: "http://localhost:7000",
		})

		if client.actualPort != 7000 {
			t.Errorf("Expected port 7000, got %d", client.actualPort)
		}
		if client.actualHost != "localhost" {
			t.Errorf("Expected host localhost, got %s", client.actualHost)
		}
		if !client.isExternalServer {
			t.Error("Expected isExternalServer to be true")
		}
	})

	t.Run("should parse https://host:port URL format", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			CLIUrl: "https://example.com:443",
		})

		if client.actualPort != 443 {
			t.Errorf("Expected port 443, got %d", client.actualPort)
		}
		if client.actualHost != "example.com" {
			t.Errorf("Expected host example.com, got %s", client.actualHost)
		}
		if !client.isExternalServer {
			t.Error("Expected isExternalServer to be true")
		}
	})

	t.Run("should throw error for invalid URL format", func(t *testing.T) {
		defer func() {
			if r := recover(); r == nil {
				t.Error("Expected panic for invalid URL format")
			} else {
				matched, _ := regexp.MatchString("Invalid port in CLIUrl", r.(string))
				if !matched {
					t.Errorf("Expected panic message to contain 'Invalid port in CLIUrl', got: %v", r)
				}
			}
		}()

		NewClient(&ClientOptions{
			CLIUrl: "invalid-url",
		})
	})

	t.Run("should throw error for invalid port - too high", func(t *testing.T) {
		defer func() {
			if r := recover(); r == nil {
				t.Error("Expected panic for invalid port")
			} else {
				matched, _ := regexp.MatchString("Invalid port in CLIUrl", r.(string))
				if !matched {
					t.Errorf("Expected panic message to contain 'Invalid port in CLIUrl', got: %v", r)
				}
			}
		}()

		NewClient(&ClientOptions{
			CLIUrl: "localhost:99999",
		})
	})

	t.Run("should throw error for invalid port - zero", func(t *testing.T) {
		defer func() {
			if r := recover(); r == nil {
				t.Error("Expected panic for invalid port")
			} else {
				matched, _ := regexp.MatchString("Invalid port in CLIUrl", r.(string))
				if !matched {
					t.Errorf("Expected panic message to contain 'Invalid port in CLIUrl', got: %v", r)
				}
			}
		}()

		NewClient(&ClientOptions{
			CLIUrl: "localhost:0",
		})
	})

	t.Run("should throw error for invalid port - negative", func(t *testing.T) {
		defer func() {
			if r := recover(); r == nil {
				t.Error("Expected panic for invalid port")
			} else {
				matched, _ := regexp.MatchString("Invalid port in CLIUrl", r.(string))
				if !matched {
					t.Errorf("Expected panic message to contain 'Invalid port in CLIUrl', got: %v", r)
				}
			}
		}()

		NewClient(&ClientOptions{
			CLIUrl: "localhost:-1",
		})
	})

	t.Run("should throw error when CLIUrl is used with UseStdio", func(t *testing.T) {
		defer func() {
			if r := recover(); r == nil {
				t.Error("Expected panic for mutually exclusive options")
			} else {
				matched, _ := regexp.MatchString("CLIUrl is mutually exclusive", r.(string))
				if !matched {
					t.Errorf("Expected panic message to contain 'CLIUrl is mutually exclusive', got: %v", r)
				}
			}
		}()

		NewClient(&ClientOptions{
			CLIUrl:   "localhost:8080",
			UseStdio: Bool(true),
		})
	})

	t.Run("should throw error when CLIUrl is used with CLIPath", func(t *testing.T) {
		defer func() {
			if r := recover(); r == nil {
				t.Error("Expected panic for mutually exclusive options")
			} else {
				matched, _ := regexp.MatchString("CLIUrl is mutually exclusive", r.(string))
				if !matched {
					t.Errorf("Expected panic message to contain 'CLIUrl is mutually exclusive', got: %v", r)
				}
			}
		}()

		NewClient(&ClientOptions{
			CLIUrl:  "localhost:8080",
			CLIPath: "/path/to/cli",
		})
	})

	t.Run("should set UseStdio to false when CLIUrl is provided", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			CLIUrl: "8080",
		})

		if client.useStdio {
			t.Error("Expected UseStdio to be false when CLIUrl is provided")
		}
	})

	t.Run("should set UseStdio to true when UseStdio is set to true", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			UseStdio: Bool(true),
		})

		if !client.useStdio {
			t.Error("Expected UseStdio to be true when UseStdio is set to true")
		}
	})

	t.Run("should set UseStdio to false when UseStdio is set to false", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			UseStdio: Bool(false),
		})

		if client.useStdio {
			t.Error("Expected UseStdio to be false when UseStdio is set to false")
		}
	})

	t.Run("should mark client as using external server", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			CLIUrl: "localhost:8080",
		})

		if !client.isExternalServer {
			t.Error("Expected isExternalServer to be true when CLIUrl is provided")
		}
	})
}

func TestClient_AuthOptions(t *testing.T) {
	t.Run("should accept GitHubToken option", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			GitHubToken: "gho_test_token",
		})

		if client.options.GitHubToken != "gho_test_token" {
			t.Errorf("Expected GitHubToken to be 'gho_test_token', got %q", client.options.GitHubToken)
		}
	})

	t.Run("should default UseLoggedInUser to nil when no GitHubToken", func(t *testing.T) {
		client := NewClient(&ClientOptions{})

		if client.options.UseLoggedInUser != nil {
			t.Errorf("Expected UseLoggedInUser to be nil, got %v", client.options.UseLoggedInUser)
		}
	})

	t.Run("should allow explicit UseLoggedInUser false", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			UseLoggedInUser: Bool(false),
		})

		if client.options.UseLoggedInUser == nil || *client.options.UseLoggedInUser != false {
			t.Error("Expected UseLoggedInUser to be false")
		}
	})

	t.Run("should allow explicit UseLoggedInUser true with GitHubToken", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			GitHubToken:     "gho_test_token",
			UseLoggedInUser: Bool(true),
		})

		if client.options.UseLoggedInUser == nil || *client.options.UseLoggedInUser != true {
			t.Error("Expected UseLoggedInUser to be true")
		}
	})

	t.Run("should throw error when GitHubToken is used with CLIUrl", func(t *testing.T) {
		defer func() {
			if r := recover(); r == nil {
				t.Error("Expected panic for auth options with CLIUrl")
			} else {
				matched, _ := regexp.MatchString("GitHubToken and UseLoggedInUser cannot be used with CLIUrl", r.(string))
				if !matched {
					t.Errorf("Expected panic message about auth options, got: %v", r)
				}
			}
		}()

		NewClient(&ClientOptions{
			CLIUrl:      "localhost:8080",
			GitHubToken: "gho_test_token",
		})
	})

	t.Run("should throw error when UseLoggedInUser is used with CLIUrl", func(t *testing.T) {
		defer func() {
			if r := recover(); r == nil {
				t.Error("Expected panic for auth options with CLIUrl")
			} else {
				matched, _ := regexp.MatchString("GitHubToken and UseLoggedInUser cannot be used with CLIUrl", r.(string))
				if !matched {
					t.Errorf("Expected panic message about auth options, got: %v", r)
				}
			}
		}()

		NewClient(&ClientOptions{
			CLIUrl:          "localhost:8080",
			UseLoggedInUser: Bool(false),
		})
	})
}

func TestClient_EnvOptions(t *testing.T) {
	t.Run("should store custom environment variables", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			Env: []string{"FOO=bar", "BAZ=qux"},
		})

		if len(client.options.Env) != 2 {
			t.Errorf("Expected 2 environment variables, got %d", len(client.options.Env))
		}
		if client.options.Env[0] != "FOO=bar" {
			t.Errorf("Expected first env var to be 'FOO=bar', got %q", client.options.Env[0])
		}
		if client.options.Env[1] != "BAZ=qux" {
			t.Errorf("Expected second env var to be 'BAZ=qux', got %q", client.options.Env[1])
		}
	})

	t.Run("should default to inherit from current process", func(t *testing.T) {
		client := NewClient(&ClientOptions{})

		if want := os.Environ(); !reflect.DeepEqual(client.options.Env, want) {
			t.Errorf("Expected Env to be %v, got %v", want, client.options.Env)
		}
	})

	t.Run("should default to inherit from current process with nil options", func(t *testing.T) {
		client := NewClient(nil)

		if want := os.Environ(); !reflect.DeepEqual(client.options.Env, want) {
			t.Errorf("Expected Env to be %v, got %v", want, client.options.Env)
		}
	})

	t.Run("should allow empty environment", func(t *testing.T) {
		client := NewClient(&ClientOptions{
			Env: []string{},
		})

		if client.options.Env == nil {
			t.Error("Expected Env to be non-nil empty slice")
		}
		if len(client.options.Env) != 0 {
			t.Errorf("Expected 0 environment variables, got %d", len(client.options.Env))
		}
	})
}

func findCLIPathForTest() string {
	abs, _ := filepath.Abs("../nodejs/node_modules/@github/copilot/index.js")
	if fileExistsForTest(abs) {
		return abs
	}
	return ""
}

func fileExistsForTest(path string) bool {
	_, err := os.Stat(path)
	return err == nil
}

func TestCreateSessionRequest_ClientName(t *testing.T) {
	t.Run("includes clientName in JSON when set", func(t *testing.T) {
		req := createSessionRequest{ClientName: "my-app"}
		data, err := json.Marshal(req)
		if err != nil {
			t.Fatalf("Failed to marshal: %v", err)
		}
		var m map[string]any
		if err := json.Unmarshal(data, &m); err != nil {
			t.Fatalf("Failed to unmarshal: %v", err)
		}
		if m["clientName"] != "my-app" {
			t.Errorf("Expected clientName to be 'my-app', got %v", m["clientName"])
		}
	})

	t.Run("omits clientName from JSON when empty", func(t *testing.T) {
		req := createSessionRequest{}
		data, _ := json.Marshal(req)
		var m map[string]any
		json.Unmarshal(data, &m)
		if _, ok := m["clientName"]; ok {
			t.Error("Expected clientName to be omitted when empty")
		}
	})
}

func TestResumeSessionRequest_ClientName(t *testing.T) {
	t.Run("includes clientName in JSON when set", func(t *testing.T) {
		req := resumeSessionRequest{SessionID: "s1", ClientName: "my-app"}
		data, err := json.Marshal(req)
		if err != nil {
			t.Fatalf("Failed to marshal: %v", err)
		}
		var m map[string]any
		if err := json.Unmarshal(data, &m); err != nil {
			t.Fatalf("Failed to unmarshal: %v", err)
		}
		if m["clientName"] != "my-app" {
			t.Errorf("Expected clientName to be 'my-app', got %v", m["clientName"])
		}
	})

	t.Run("omits clientName from JSON when empty", func(t *testing.T) {
		req := resumeSessionRequest{SessionID: "s1"}
		data, _ := json.Marshal(req)
		var m map[string]any
		json.Unmarshal(data, &m)
		if _, ok := m["clientName"]; ok {
			t.Error("Expected clientName to be omitted when empty")
		}
	})
}

func TestClient_CreateSession_RequiresPermissionHandler(t *testing.T) {
	t.Run("returns error when config is nil", func(t *testing.T) {
		client := NewClient(nil)
		_, err := client.CreateSession(t.Context(), nil)
		if err == nil {
			t.Fatal("Expected error when OnPermissionRequest is nil")
		}
		matched, _ := regexp.MatchString("OnPermissionRequest.*is required", err.Error())
		if !matched {
			t.Errorf("Expected error about OnPermissionRequest being required, got: %v", err)
		}
	})

	t.Run("returns error when OnPermissionRequest is not set", func(t *testing.T) {
		client := NewClient(nil)
		_, err := client.CreateSession(t.Context(), &SessionConfig{})
		if err == nil {
			t.Fatal("Expected error when OnPermissionRequest is nil")
		}
		matched, _ := regexp.MatchString("OnPermissionRequest.*is required", err.Error())
		if !matched {
			t.Errorf("Expected error about OnPermissionRequest being required, got: %v", err)
		}
	})
}

func TestClient_ResumeSession_RequiresPermissionHandler(t *testing.T) {
	t.Run("returns error when config is nil", func(t *testing.T) {
		client := NewClient(nil)
		_, err := client.ResumeSessionWithOptions(t.Context(), "some-id", nil)
		if err == nil {
			t.Fatal("Expected error when OnPermissionRequest is nil")
		}
		matched, _ := regexp.MatchString("OnPermissionRequest.*is required", err.Error())
		if !matched {
			t.Errorf("Expected error about OnPermissionRequest being required, got: %v", err)
		}
	})
}