// contract_test.go：信封 golden JSON 测试（A6.1：字段与 mcp-usage 一致性 + 空数组纪律 + +08:00）。
package contract

import (
	"encoding/json"
	"strings"
	"testing"
	"time"

	"onesvm.com/onesvm/browser-server/internal/config"
)

// TestTimeMarshalPlus08 时间序列化恒带 +08:00。
func TestTimeMarshalPlus08(t *testing.T) {
	// 输入 UTC 时间，序列化后必须是 +08:00 偏移
	u := time.Date(2026, 9, 1, 3, 41, 15, 0, time.UTC) // 北京 11:41:15
	b, err := json.Marshal(NewTime(u))
	if err != nil {
		t.Fatal(err)
	}
	got := string(b)
	if !strings.Contains(got, "+08:00") {
		t.Fatalf("时间序列化缺 +08:00: %s", got)
	}
	if got != `"2026-09-01T11:41:15+08:00"` {
		t.Fatalf("时间序列化不符: %s", got)
	}
}

// TestTimeUnmarshalNorm 反序列化任意时区输入都归一到 +08:00。
func TestTimeUnmarshalNorm(t *testing.T) {
	var tt Time
	in := `"2026-09-01T02:00:00Z"`
	if err := json.Unmarshal([]byte(in), &tt); err != nil {
		t.Fatal(err)
	}
	out, _ := json.Marshal(tt)
	if !strings.Contains(string(out), "+08:00") {
		t.Fatalf("反序列化后未归一 +08:00: %s", out)
	}
}

// goldenSearchResponse mcp-usage §2.1 响应形状基准。
const goldenSearchResponse = `{"ok":true,"kind":"search","request_id":"01K3TEST","took_ms":633,` +
	`"usage":{"credits":1,"engine":"searxng-cn","tokens_estimate":350},` +
	`"provenance":{"retrieved_at":"2026-09-01T11:41:15+08:00","adapter":"searxng-cn","proxy_exit":"none","cached":false},` +
	`"error":null,"query":"跨境电商 政策","answer":null,"results":[]}`

// TestEnvelopeSearchGolden 空结果必须是 [] 而非 null；字段名与 mcp-usage §2.1 一致。
func TestEnvelopeSearchGolden(t *testing.T) {
	env := Envelope{
		OK:        true,
		Kind:      "search",
		RequestID: "01K3TEST",
		TookMs:    633,
		Usage:     Usage{Credits: 1, Engine: "searxng-cn", TokensEstimate: 350},
		Provenance: Provenance{
			RetrievedAt: NewTime(time.Date(2026, 9, 1, 11, 41, 15, 0, config.TZ)),
			Adapter:     "searxng-cn",
			ProxyExit:   "none",
			Cached:      false,
		},
		Error: nil,
		Data: &SearchPayload{
			Query:   "跨境电商 政策",
			Answer:  nil,
			Results: nil, // 关键：nil 也必须出 []
		},
	}
	b, err := json.Marshal(env)
	if err != nil {
		t.Fatal(err)
	}
	got := string(b)
	if got != goldenSearchResponse {
		t.Fatalf("golden 不符:\n got: %s\nwant: %s", got, goldenSearchResponse)
	}
	if strings.Contains(got, `"results":null`) {
		t.Fatal("results 为 null，违反空数组纪律")
	}
}

// TestEnvelopeReadShape read 字段齐备性（mcp-usage §2.2）。
func TestEnvelopeReadShape(t *testing.T) {
	md := "正文"
	env := Envelope{
		OK:        true,
		Kind:      "read",
		RequestID: "r1",
		Data: &ReadPayload{
			URL:       "https://example.com",
			FinalURL:  "https://example.com",
			Title:     "标题",
			Markdown:  md,
			CharCount: len([]rune(md)),
			Metadata:  ReadMetadata{StatusCode: 200, ContentType: "text/html", RetrievedAt: NowTime()},
			// Links/Images/Warnings 全 nil：必须序列化为 []
		},
	}
	b, err := json.Marshal(env)
	if err != nil {
		t.Fatal(err)
	}
	s := string(b)
	for _, want := range []string{`"links":[]`, `"images":[]`, `"warnings":[]`,
		`"markdown":"正文"`, `"truncated":false`, `"screenshot_url":null`, `"extracted":null`} {
		if !strings.Contains(s, want) {
			t.Fatalf("read 信封缺 %s: %s", want, s)
		}
	}
	if strings.Contains(s, `"links":null`) || strings.Contains(s, `"images":null`) {
		t.Fatal("links/images 为 null，违反空数组纪律")
	}
}

// TestErrBodyHTTPStatus 错误码 → HTTP 状态映射（mcp-usage §3 表）。
func TestErrBodyHTTPStatus(t *testing.T) {
	cases := map[string]int{
		CodeRateLimited: 429, CodeQuota: 402, CodeDenied: 403,
		CodeUnauthorized: 401, CodeUnavailable: 503, CodeTimeout: 504,
		CodeUpstream: 502, CodeBlocked: 200, CodeExtractFailed: 200,
	}
	for code, want := range cases {
		if got := (ErrBody{Code: code}).HTTPStatus(); got != want {
			t.Errorf("code=%s got=%d want=%d", code, got, want)
		}
	}
}

// TestRetryable 瞬时错误判定（仅 timeout/upstream）。
func TestRetryable(t *testing.T) {
	if !Retryable(CodeTimeout) || !Retryable(CodeUpstream) {
		t.Fatal("timeout/upstream 应可重试")
	}
	for _, c := range []string{CodeDenied, CodeQuota, CodeRateLimited, CodeBlocked} {
		if Retryable(c) {
			t.Errorf("code=%s 不应可重试", c)
		}
	}
}

// TestCapsMatch 能力路由标签匹配。
func TestCapsMatch(t *testing.T) {
	c := Caps{Intents: []string{"search", "read"}, Render: RenderLight,
		Regions: []string{"domestic", "overseas"}}
	if err := c.Match("search", RegionOverseas, RenderNone); err != nil {
		t.Fatalf("应满足: %v", err)
	}
	if err := c.Match("search", RegionOverseas, RenderFull); err == nil {
		t.Fatal("light 适配器不应满足 full 需求")
	}
	c2 := Caps{Intents: []string{"search"}, Render: RenderNone, Regions: []string{"domestic"}}
	if err := c2.Match("read", RegionOverseas, RenderNone); err == nil {
		t.Fatal("不支持 read+overseas 的适配器应被拒")
	}
}

// TestValidRegion region 校验与默认。
func TestValidRegion(t *testing.T) {
	if r, _ := ValidRegion(""); r != RegionDomestic {
		t.Fatal("空 region 应默认 domestic")
	}
	if _, err := ValidRegion("mars"); err == nil {
		t.Fatal("非法 region 应报错")
	}
}