package search

import (
	"context"
	"errors"
	"net/http"
	"net/http/httptest"
	"testing"
)

// TestRegistry_KnownAndKnownNames 覆盖「哪些名字是本期接入位」：认识的家（含未配置的）
// 与不认识的家必须分得开 —— 这正是启动期「未注册 vs 未配置」两种报错的判据。
func TestRegistry_KnownAndKnownNames(t *testing.T) {
	t.Parallel()
	for _, name := range []string{
		NameSearXNG, NameZhipu, NameAliyunIQS, NameBocha, NameVolcengine, NameBaiduQianfan,
		"Zhipu", "  bocha  ",
	} {
		if !Known(name) {
			t.Errorf("Known(%q) = false, want true（大小写/空白应不敏感）", name)
		}
	}
	for _, name := range []string{"", "tavily", "exa", "firecrawl", "serper", "serpapi", "nope"} {
		if Known(name) {
			t.Errorf("Known(%q) = true, want false（本期未登记）", name)
		}
	}
	names := KnownNames()
	if len(names) != 6 {
		t.Fatalf("KnownNames() = %v, want 六家", names)
	}
}

// TestRegistry_Configured 钉住「配齐」的判定口径：searxng 无 key、看 base URL；
// 云家看 API key。它是「未配置的家不出现在可用清单里」的唯一判据。
func TestRegistry_Configured(t *testing.T) {
	t.Parallel()
	cases := []struct {
		name           string
		provider       string
		key, base      string
		wantConfigured bool
	}{
		{"searxng 有端点无 key 也算配置齐", NameSearXNG, "", "http://127.0.0.1:38471", true},
		{"searxng 没端点 = 未配置", NameSearXNG, "whatever", "  ", false},
		{"云家有 key = 配置齐", NameZhipu, "k", "", true},
		{"云家没 key = 未配置", NameZhipu, "   ", "https://open.bigmodel.cn", false},
		{"未登记的名字一律未配置", "tavily", "k", "https://api.tavily.com", false},
	}
	for _, tc := range cases {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			if got := Configured(tc.provider, tc.key, tc.base); got != tc.wantConfigured {
				t.Fatalf("Configured(%q,%q,%q) = %v, want %v", tc.provider, tc.key, tc.base, got, tc.wantConfigured)
			}
		})
	}
}

// TestRegistry_BuildOnlyRegistersConfigured 钉住 fail-closed：未配置的家根本不进注册表，
// 因而**不出现在可用清单里**（design/27 §1.2）。
func TestRegistry_BuildOnlyRegistersConfigured(t *testing.T) {
	t.Parallel()
	wires := []Wire{
		{Name: NameBocha, APIKey: "k", BaseURL: "https://api.bocha.cn", Configured: true},
		{Name: NameZhipu, APIKey: "", BaseURL: "https://open.bigmodel.cn", Configured: false},
		{Name: "tavily", APIKey: "k", BaseURL: "https://api.tavily.com", Configured: true},
		{Name: NameBocha, APIKey: "k2", BaseURL: "https://api.bocha.cn", Configured: true}, // 重复
	}
	reg := Build(wires, &http.Client{}, defaultMaxBytes, nil)
	names := reg.Names()
	if len(names) != 1 || names[0] != NameBocha {
		t.Fatalf("可用清单 = %v, want [bocha]（未配置的家与未登记的名字都不得出现）", names)
	}
	if _, ok := reg.Lookup(NameZhipu); ok {
		t.Fatal("缺 key 的家不得出现在注册表里")
	}
	if _, ok := reg.Lookup("tavily"); ok {
		t.Fatal("未登记的名字不得出现在注册表里")
	}
	if p, ok := reg.Lookup("  BOCHA "); !ok || p.Name() != NameBocha {
		t.Fatalf("Lookup 应大小写/空白不敏感, got %v %v", p, ok)
	}
}

// TestRegistry_EmptyAndNilSafe 覆盖零值路径：空注册表 / nil 注册表不得 panic。
func TestRegistry_EmptyAndNilSafe(t *testing.T) {
	t.Parallel()
	reg := Build(nil, &http.Client{}, 0, nil)
	if len(reg.Names()) != 0 {
		t.Fatalf("空接线表应得到空注册表: %v", reg.Names())
	}
	if _, ok := reg.Lookup("zhipu"); ok {
		t.Fatal("空注册表不该命中任何名字")
	}
	var nilReg *Registry
	if _, ok := nilReg.Lookup("zhipu"); ok {
		t.Fatal("nil 注册表应安全返回 false")
	}
	if len(nilReg.Names()) != 0 {
		t.Fatal("nil 注册表应返回空清单")
	}
}

// TestProviders_ErrorClassification 是验收 ⑤：鉴权 / 限流 / 额度 / 上游 各一条。
// 用同一家 provider + 不同应答，确认分类**如实区分**（错误分类决定降级链是否前进）。
func TestProviders_ErrorClassification(t *testing.T) {
	t.Parallel()
	cases := []struct {
		name    string
		status  int
		body    string
		wantErr error
	}{
		{"鉴权失败 401", http.StatusUnauthorized, `{"error":"bad key"}`, ErrUnauthorized},
		{"限流 429", http.StatusTooManyRequests, `{"error":"too many"}`, ErrRateLimited},
		{"额度/欠费（403 + 官方错误码）", http.StatusForbidden,
			`{"code":"Retrieval.Arrears","message":"账户欠费"}`, ErrQuotaExceeded},
		{"未开通（403 + 官方错误码）", http.StatusForbidden,
			`{"code":"Retrieval.NotActivate"}`, ErrQuotaExceeded},
		{"上游 500", http.StatusInternalServerError, `{}`, ErrUpstream},
	}
	for _, tc := range cases {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
				w.WriteHeader(tc.status)
				_, _ = w.Write([]byte(tc.body))
			}))
			defer srv.Close()
			p := newZhipu(Config{APIKey: testKey, BaseURL: srv.URL, Client: srv.Client()})
			if _, err := p.Search(context.Background(), Query{Text: "q"}); !errors.Is(err, tc.wantErr) {
				t.Fatalf("err = %v, want errors.Is(..., %v)", err, tc.wantErr)
			}
		})
	}
}

// TestProviders_TransportFailures 覆盖非 HTTP 状态类的失败：网络 / 读取上限 /
// 没有客户端 / 注入守卫被调用。它们同样要**如实分类**，不许混成一团。
func TestProviders_TransportFailures(t *testing.T) {
	t.Parallel()
	t.Run("网络失败", func(t *testing.T) {
		t.Parallel()
		srv := httptest.NewServer(http.HandlerFunc(func(http.ResponseWriter, *http.Request) {}))
		url := srv.URL
		srv.Close() // 关掉之后再打 ⇒ 连接被拒
		p := newZhipu(Config{APIKey: testKey, BaseURL: url, Client: &http.Client{}})
		if _, err := p.Search(context.Background(), Query{Text: "q"}); !errors.Is(err, ErrNetwork) {
			t.Fatalf("err = %v, want ErrNetwork", err)
		}
	})

	t.Run("响应超上限", func(t *testing.T) {
		t.Parallel()
		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
			_, _ = w.Write([]byte(`{"search_result":[{"title":"很长"}]}`))
		}))
		defer srv.Close()
		p := newZhipu(Config{APIKey: testKey, BaseURL: srv.URL, Client: srv.Client(), MaxBytes: 8})
		if _, err := p.Search(context.Background(), Query{Text: "q"}); !errors.Is(err, ErrResponseTooLarge) {
			t.Fatalf("err = %v, want ErrResponseTooLarge", err)
		}
	})

	t.Run("没有 HTTP 客户端", func(t *testing.T) {
		t.Parallel()
		p := newZhipu(Config{APIKey: testKey, BaseURL: "https://open.bigmodel.cn"})
		if _, err := p.Search(context.Background(), Query{Text: "q"}); !errors.Is(err, ErrNotConfigured) {
			t.Fatalf("err = %v, want ErrNotConfigured", err)
		}
	})

	t.Run("注入的 SSRF 守卫被调用", func(t *testing.T) {
		t.Parallel()
		called := false
		blocked := errors.New("blocked by guard")
		p := newZhipu(Config{
			APIKey: testKey, BaseURL: "https://open.bigmodel.cn", Client: &http.Client{},
			Guard: func(context.Context, string) error { called = true; return blocked },
		})
		if _, err := p.Search(context.Background(), Query{Text: "q"}); !errors.Is(err, blocked) {
			t.Fatalf("err = %v, want wrapped guard error", err)
		}
		if !called {
			t.Fatal("注入的守卫没被调用 —— SSRF 判定成了死代码")
		}
	})
}

// TestClassifyStatus 是状态码分类的表驱动（含业务码优先于状态码）。
func TestClassifyStatus(t *testing.T) {
	t.Parallel()
	cases := []struct {
		status  int
		code    string
		wantErr error
	}{
		{http.StatusUnauthorized, "", ErrUnauthorized},
		{http.StatusForbidden, "", ErrUnauthorized},
		{http.StatusPaymentRequired, "", ErrQuotaExceeded},
		{http.StatusTooManyRequests, "", ErrRateLimited},
		{http.StatusInternalServerError, "", ErrUpstream},
		{http.StatusBadRequest, "", ErrUpstream},
		// 业务码优先：403 也可能是额度（阿里云官方错误码表确证）。
		{http.StatusForbidden, "Retrieval.Arrears", ErrQuotaExceeded},
		{http.StatusForbidden, "retrieval.throttling.user", ErrRateLimited},
		{http.StatusForbidden, "Retrieval.NotAuthorised", ErrUnauthorized},
	}
	for _, tc := range cases {
		if got := classifyStatus(tc.status, tc.code); !errors.Is(got, tc.wantErr) {
			t.Errorf("classifyStatus(%d,%q) = %v, want %v", tc.status, tc.code, got, tc.wantErr)
		}
	}
}

// TestUpstreamCode 覆盖业务错误码的候选位置抽取。
func TestUpstreamCode(t *testing.T) {
	t.Parallel()
	cases := []struct {
		body string
		want string
	}{
		{`{"code":"Retrieval.Arrears"}`, "Retrieval.Arrears"},
		{`{"error":{"code":"abc"}}`, "abc"},
		{`{"ErrorCode":"xyz"}`, "xyz"},
		{`{"message":"no code here"}`, ""},
		{`not json`, ""},
		{``, ""},
	}
	for _, tc := range cases {
		if got := upstreamCode([]byte(tc.body)); got != tc.want {
			t.Errorf("upstreamCode(%q) = %q, want %q", tc.body, got, tc.want)
		}
	}
}

// TestUnavailable 钉住降级链的判据：**空结果不是「不可用」**（不该前进一格）。
func TestUnavailable(t *testing.T) {
	t.Parallel()
	for _, err := range []error{
		ErrNotConfigured, ErrUnauthorized, ErrRateLimited, ErrQuotaExceeded,
		ErrNetwork, ErrUpstream, ErrResponseTooLarge, ErrBadResponse,
	} {
		if !Unavailable(err) {
			t.Errorf("Unavailable(%v) = false, want true（该家不可用 ⇒ 前进一格）", err)
		}
	}
	for _, err := range []error{nil, ErrNoResults, context.Canceled, context.DeadlineExceeded} {
		if Unavailable(err) {
			t.Errorf("Unavailable(%v) = true, want false（不是「不可用」）", err)
		}
	}
}