package handler

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestHealth(t *testing.T) {
	request := httptest.NewRequest(http.MethodGet, "/health", nil)
	response := httptest.NewRecorder()

	NewRouter().ServeHTTP(response, request)

	if response.Code != http.StatusOK {
		t.Fatalf("status = %d, want %d", response.Code, http.StatusOK)
	}
	if got := response.Header().Get("Content-Type"); got != "application/json; charset=utf-8" {
		t.Fatalf("Content-Type = %q, want application/json; charset=utf-8", got)
	}

	var body healthResponse
	if err := json.NewDecoder(response.Body).Decode(&body); err != nil {
		t.Fatalf("decode response: %v", err)
	}
	if body.Status != "ok" {
		t.Fatalf("status body = %q, want ok", body.Status)
	}
}

func TestHealthRejectsOtherMethods(t *testing.T) {
	request := httptest.NewRequest(http.MethodPost, "/health", nil)
	response := httptest.NewRecorder()

	NewRouter().ServeHTTP(response, request)

	if response.Code != http.StatusMethodNotAllowed {
		t.Fatalf("status = %d, want %d", response.Code, http.StatusMethodNotAllowed)
	}
}

func TestRouterDoesNotExposeMCPWithoutConfiguredHandler(t *testing.T) {
	request := httptest.NewRequest(http.MethodPost, "/mcp", nil)
	response := httptest.NewRecorder()

	NewRouter().ServeHTTP(response, request)

	if response.Code != http.StatusNotFound {
		t.Fatalf("status = %d, want %d", response.Code, http.StatusNotFound)
	}
}

func TestRouterRegistersConfiguredMCPHandler(t *testing.T) {
	request := httptest.NewRequest(http.MethodPost, "/mcp", nil)
	response := httptest.NewRecorder()
	mcp := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusAccepted)
	})

	NewRouter(RouterOptions{MCP: mcp}).ServeHTTP(response, request)

	if response.Code != http.StatusAccepted {
		t.Fatalf("status = %d, want %d", response.Code, http.StatusAccepted)
	}
}

func TestRouterRegistersConfiguredDashScopeChatHandler(t *testing.T) {
	request := httptest.NewRequest(http.MethodPost, "/api/v1/apps/test-app/completion", nil)
	response := httptest.NewRecorder()
	chat := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.PathValue("app_id") != "test-app" {
			t.Fatalf("app_id = %q", r.PathValue("app_id"))
		}
		w.WriteHeader(http.StatusAccepted)
	})

	NewRouter(RouterOptions{DashScopeChat: chat}).ServeHTTP(response, request)

	if response.Code != http.StatusAccepted {
		t.Fatalf("status = %d, want %d", response.Code, http.StatusAccepted)
	}
}

func TestRouterDoesNotExposeChatPageWithoutConfiguredHandler(t *testing.T) {
	for _, path := range []string{"/chat", "/chat/", "/chat/app.js", "/chat/app.css"} {
		request := httptest.NewRequest(http.MethodGet, path, nil)
		response := httptest.NewRecorder()

		NewRouter().ServeHTTP(response, request)

		if response.Code != http.StatusNotFound {
			t.Fatalf("%s status = %d, want %d", path, response.Code, http.StatusNotFound)
		}
	}
}

func TestRouterRegistersConfiguredChatPageHandler(t *testing.T) {
	page, err := NewChatPageHandler(ChatPageOptions{AppID: "fire-safety-app"})
	if err != nil {
		t.Fatalf("NewChatPageHandler() error = %v", err)
	}

	request := httptest.NewRequest(http.MethodGet, "/chat/", nil)
	response := httptest.NewRecorder()
	NewRouter(RouterOptions{ChatPage: page}).ServeHTTP(response, request)
	if response.Code != http.StatusOK {
		t.Fatalf("/chat/ status = %d, want %d", response.Code, http.StatusOK)
	}

	request = httptest.NewRequest(http.MethodGet, "/chat", nil)
	response = httptest.NewRecorder()
	NewRouter(RouterOptions{ChatPage: page}).ServeHTTP(response, request)
	if response.Code != http.StatusPermanentRedirect || response.Header().Get("Location") != "/chat/" {
		t.Fatalf("/chat status = %d location = %q, want redirect to /chat/", response.Code, response.Header().Get("Location"))
	}

	request = httptest.NewRequest(http.MethodGet, "/chat/app.js", nil)
	response = httptest.NewRecorder()
	NewRouter(RouterOptions{ChatPage: page}).ServeHTTP(response, request)
	if response.Code != http.StatusOK || response.Header().Get("Content-Type") != "text/javascript; charset=utf-8" {
		t.Fatalf("/chat/app.js status = %d content-type = %q, want JavaScript 200", response.Code, response.Header().Get("Content-Type"))
	}
}