package cdp

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"sync"
	"testing"
)

// fakeBrowserEnv 构造完整的假调试端点：/json/list、/json/new（PUT）、
// 每个 target 的 ws 端点（CDP 协议）。
func fakeBrowserEnv(t *testing.T) (*Browser, *httptest.Server) {
	t.Helper()
	var mu sync.Mutex
	targets := []Target{{
		ID: "t1", Title: "Blank", URL: "about:blank", Type: "page",
		WebSocketDebuggerURL: "", // srv.URL 已知后再填
	}}
	var srv *httptest.Server

	wsHandler := fakeCDPHandler(t, "Fake Page")
	mux := http.NewServeMux()
	mux.HandleFunc("/json/list", func(w http.ResponseWriter, r *http.Request) {
		mu.Lock()
		defer mu.Unlock()
		_ = json.NewEncoder(w).Encode(targets)
	})
	mux.HandleFunc("/json/new", func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPut {
			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
			return
		}
		mu.Lock()
		targets = append(targets, Target{ID: "t2", Title: "New", URL: r.URL.Query().Get("url"), Type: "page"})
		nt := targets[len(targets)-1]
		mu.Unlock()
		_ = json.NewEncoder(w).Encode(nt)
	})
	mux.HandleFunc("/devtools/page/t1", wsHandler)
	mux.HandleFunc("/devtools/page/t2", wsHandler)

	srv = httptest.NewServer(mux)
	mu.Lock()
	targets[0].WebSocketDebuggerURL = "ws" + strings.TrimPrefix(srv.URL, "http") + "/devtools/page/t1"
	mu.Unlock()

	br := &Browser{DebugBase: srv.URL}
	t.Cleanup(func() { srv.Close(); br.Close() })
	return br, srv
}

func TestBrowserToolEndToEnd(t *testing.T) {
	br, _ := fakeBrowserEnv(t)
	tool := browserToolWith(br)
	ctx := context.Background()

	// tabs
	res, err := tool.Run(ctx, `{"action":"tabs"}`)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(res.Text, "t1 | Blank | about:blank") {
		t.Fatalf("tabs: %q", res.Text)
	}

	// open：navigate + loadEventFired + 读取标题
	res, err = tool.Run(ctx, `{"action":"open","url":"https://example.com/x"}`)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(res.Text, "opened https://example.com/x") || !strings.Contains(res.Text, "Fake Page") {
		t.Fatalf("open: %q", res.Text)
	}

	// js：Runtime.evaluate 结果 + 错误路径
	res, err = tool.Run(ctx, `{"action":"js","javascript":"document.title"}`)
	if err != nil {
		t.Fatal(err)
	}
	if res.Text != "Fake Page" {
		t.Fatalf("js: %q", res.Text)
	}

	// screenshot：PNG 落盘并作为 Image 返回
	res, err = tool.Run(ctx, `{"action":"screenshot"}`)
	if err != nil {
		t.Fatal(err)
	}
	if len(res.Images) != 1 {
		t.Fatalf("screenshot images: %v", res.Images)
	}
	data, err := os.ReadFile(res.Images[0].Path)
	if err != nil {
		t.Fatal(err)
	}
	if string(data[:4]) != "\x89PNG" {
		t.Fatalf("not a png: %x", data[:4])
	}
	os.Remove(res.Images[0].Path)

	// 参数校验
	if _, err := tool.Run(ctx, `{"action":"open"}`); err == nil {
		t.Fatal("open without url should fail")
	}
	if _, err := tool.Run(ctx, `{"action":"js"}`); err == nil {
		t.Fatal("js without javascript should fail")
	}
	if _, err := tool.Run(ctx, `{"action":"bogus"}`); err == nil {
		t.Fatal("unknown action should fail")
	}
}

// TestNewTabPUT：无 page target 时经 PUT /json/new 新开 tab。
func TestNewTabPUT(t *testing.T) {
	br, srv := fakeBrowserEnv(t)
	// 清空 targets：强制走 NewTab
	_ = srv
	ctx := context.Background()
	tg, err := br.NewTab(ctx, "https://example.com/new")
	if err != nil {
		t.Fatal(err)
	}
	if tg.ID != "t2" || tg.URL != "https://example.com/new" {
		t.Fatalf("new tab: %+v", tg)
	}
}

// TestFindBrowserExplicit：显式指定不存在的二进制给出可操作错误。
func TestFindBrowserExplicit(t *testing.T) {
	if _, err := findBrowser("/no/such/browser"); err == nil || !strings.Contains(err.Error(), "AUTOGO_BROWSER_BIN") {
		t.Fatalf("expected explicit-bin error, got %v", err)
	}
}