package search

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

// 本文件钉住「测试连通」探针（design/09 §5.2 示例的 plugin.testProvider）的结论语义：
// 真发一次请求、空结果 ≠ 不通、凭据绝不进结果、失败必须可分类。

// wsProbeServer 起一个只说博查形状的假上游，把收到的请求送进 got 供断言。
func wsProbeServer(t *testing.T, status int, body string) (*httptest.Server, chan *http.Request) {
	t.Helper()
	got := make(chan *http.Request, 1)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		got <- r
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(status)
		_, _ = w.Write([]byte(body))
	}))
	t.Cleanup(srv.Close)
	return srv, got
}

// 判据 ①：通了 ⇒ OK + 真实条数；且真的打到了那家的固定路径上，凭据真的带上了。
func TestProbeOKHitsProviderWithCredential(t *testing.T) {
	t.Parallel()
	const key = "probe-secret-key"
	srv, got := wsProbeServer(t, http.StatusOK,
		`{"webPages":{"value":[{"name":"标题","url":"https://a.example/1","summary":"正文"}]}}`)

	res := Probe(context.Background(), NameBocha, Config{
		APIKey: key, BaseURL: srv.URL, Client: srv.Client(), MaxBytes: 1 << 20,
	}, 1)
	if !res.OK || res.Count != 1 {
		t.Fatalf("探针结论 = %+v, want OK/count=1", res)
	}
	if res.Provider != NameBocha {
		t.Fatalf("provider = %q, want %q", res.Provider, NameBocha)
	}
	if res.ErrorCode != "" || res.Error != "" {
		t.Fatalf("成功时不该带错误码/文案：%+v", res)
	}
	select {
	case r := <-got:
		if r.URL.Path != "/v1/web-search" {
			t.Errorf("请求路径 = %q, want /v1/web-search（各家固定路径）", r.URL.Path)
		}
		if r.Header.Get("Authorization") != "Bearer "+key {
			t.Errorf("Authorization = %q（凭据必须真的被用上）", r.Header.Get("Authorization"))
		}
	default:
		t.Fatal("探针一个请求都没发 —— 连通性是发出来的，不是算出来的")
	}
	wsAssertNoSecret(t, res, key, srv.URL)
}

// 判据 ②：空结果 ≠ 不通 —— 报 no_results，既不算成功、也不算「这家不可用」。
func TestProbeEmptyResultsIsNoResultsNotFailure(t *testing.T) {
	t.Parallel()
	srv, _ := wsProbeServer(t, http.StatusOK, `{"webPages":{"value":[]}}`)
	res := Probe(context.Background(), NameBocha, Config{
		APIKey: "k", BaseURL: srv.URL, Client: srv.Client(),
	}, 1)
	if res.OK {
		t.Fatalf("空结果不得算成功：%+v", res)
	}
	if res.ErrorCode != ProbeNoResults {
		t.Fatalf("ErrorCode = %q, want %q", res.ErrorCode, ProbeNoResults)
	}
}

// 判据 ③：失败必须可分类，且**文案里不许出现上游 URL/凭据**。
func TestProbeFailureClassesAndNoLeak(t *testing.T) {
	t.Parallel()
	cases := []struct {
		name   string
		status int
		body   string
		want   string
	}{
		{"凭据被拒", http.StatusUnauthorized, `{"error":{"code":"unauthorized"}}`, ProbeUnauthorized},
		{"限流", http.StatusTooManyRequests, `{}`, ProbeRateLimited},
		{"上游 5xx", http.StatusBadGateway, `{}`, ProbeUpstream},
		{"应答不是预期结构", http.StatusOK, `{"unexpected":true}`, ProbeBadResponse},
	}
	for _, tc := range cases {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			const key = "probe-secret-key"
			srv, _ := wsProbeServer(t, tc.status, tc.body)
			res := Probe(context.Background(), NameBocha, Config{
				APIKey: key, BaseURL: srv.URL, Client: srv.Client(),
			}, 1)
			if res.OK {
				t.Fatalf("失败不得报 OK：%+v", res)
			}
			if res.ErrorCode != tc.want {
				t.Fatalf("ErrorCode = %q, want %q（文案=%q）", res.ErrorCode, tc.want, res.Error)
			}
			if res.Error == "" {
				t.Fatal("失败必须带一句可读文案（错误码与文案分离，前端可本地化）")
			}
			wsAssertNoSecret(t, res, key, srv.URL)
		})
	}
}

// 判据 ④：名字没登记 / 没配齐 / 没客户端，三类都别去发请求，且分类准确。
func TestProbePreflightRejectsBeforeSending(t *testing.T) {
	t.Parallel()
	cases := []struct {
		name string
		prov string
		cfg  Config
		want string
	}{
		{"没登记的名字", "tavily", Config{APIKey: "k", BaseURL: "https://t.example"}, ProbeUnknownProvider},
		{"云家缺 key", NameBocha, Config{BaseURL: "https://b.example"}, ProbeNotConfigured},
		{"缺接口地址", NameBocha, Config{APIKey: "k"}, ProbeNotConfigured},
		{"没有 http 客户端", NameBocha, Config{APIKey: "k", BaseURL: "https://b.example"}, ProbeNotConfigured},
	}
	for _, tc := range cases {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			res := Probe(context.Background(), tc.prov, tc.cfg, 1)
			if res.ErrorCode != tc.want {
				t.Fatalf("ErrorCode = %q, want %q（文案=%q）", res.ErrorCode, tc.want, res.Error)
			}
			if res.OK || res.Count != 0 {
				t.Fatalf("发不出去的探针不得报成功：%+v", res)
			}
		})
	}
}

// 判据 ⑤：网络层失败归 network（连不上也有稳定错误码，不是一团未知）。
func TestProbeNetworkFailureIsClassified(t *testing.T) {
	t.Parallel()
	srv, _ := wsProbeServer(t, http.StatusOK, `{}`)
	url := srv.URL
	srv.Close() // 关掉：后续请求必然连不上
	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
	defer cancel()
	res := Probe(ctx, NameBocha, Config{APIKey: "k", BaseURL: url, Client: &http.Client{}}, 1)
	if res.ErrorCode != ProbeNetwork {
		t.Fatalf("ErrorCode = %q, want %q", res.ErrorCode, ProbeNetwork)
	}
}

// 判据 ⑥：错误码 ↔ 文案一一对应，且未分类有兜底（不许出现「空文案的失败」）。
func TestProbeMessagesCoverEveryCode(t *testing.T) {
	t.Parallel()
	for _, code := range []string{
		ProbeUnknownProvider, ProbeNotConfigured, ProbeUnauthorized, ProbeRateLimited,
		ProbeQuotaExceeded, ProbeNetwork, ProbeUpstream, ProbeBadResponse,
		ProbeNoResults, ProbeUnknown,
	} {
		if msg := probeMessage(code); strings.TrimSpace(msg) == "" {
			t.Errorf("错误码 %q 没有文案", code)
		}
	}
	if ProbeErrorCode(nil) != "" {
		t.Fatal("nil 错误没有错误码")
	}
}

// wsAssertNoSecret 断言探针结论里既没有凭据、也没有上游 URL（两者都可能出现在上游
// 错误体或网络错误里，而这份结构会进面板响应）。
func wsAssertNoSecret(t *testing.T, res ProbeResult, secret, upstreamURL string) {
	t.Helper()
	raw, err := json.Marshal(res)
	if err != nil {
		t.Fatalf("marshal: %v", err)
	}
	if strings.Contains(string(raw), secret) {
		t.Fatalf("探针结论泄漏了凭据: %s", raw)
	}
	if strings.Contains(string(raw), upstreamURL) {
		t.Fatalf("探针结论泄漏了上游地址: %s", raw)
	}
}