package httpapi

import (
	"encoding/json"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/go-chi/chi/v5"
	"github.com/wangjia/pangolin/server/internal/nodes"
)

func testNode() *nodes.NodeRow {
	return &nodes.NodeRow{
		UUID: "n1", Endpoint: "1.2.3.4:443",
		RealityPBK: "pbk", RealityShortID: "sid", RealitySNI: "www.apple.com",
	}
}

func routeOf(t *testing.T, cfg []byte) map[string]any {
	t.Helper()
	var m map[string]any
	if err := json.Unmarshal(cfg, &m); err != nil {
		t.Fatalf("unmarshal config: %v", err)
	}
	return m["route"].(map[string]any)
}

func TestBuildClientConfigSplitCN(t *testing.T) {
	// 开启分流 + base → geoip-cn/geosite-cn rule_set + cn 直连规则;URL 自托管。
	cfg, err := BuildClientConfig(testNode(), "uuid-1", "k",
		ClientConfigOpts{SplitCN: true, RulesBaseURL: "http://node:8080/"})
	if err != nil {
		t.Fatal(err)
	}
	route := routeOf(t, cfg)
	if rs, ok := route["rule_set"].([]any); !ok || len(rs) != 2 {
		t.Fatalf("expected 2 rule_set, got %v", route["rule_set"])
	}
	s := string(cfg)
	for _, want := range []string{
		"geoip-cn", "geosite-cn",
		"http://node:8080/v1/rules/geoip-cn.srs",
		"http://node:8080/v1/rules/geosite-cn.srs",
		"download_detour",
	} {
		if !strings.Contains(s, want) {
			t.Errorf("config missing %q", want)
		}
	}
	foundCN := false
	for _, r := range route["rules"].([]any) {
		rm := r.(map[string]any)
		if rm["outbound"] == "direct" && rm["rule_set"] != nil {
			foundCN = true
		}
	}
	if !foundCN {
		t.Error("missing cn-direct route rule (rule_set→direct)")
	}

	// DNS 面分流:开分流时国内域名(geosite-cn)用 local 解析,不走 remote(隧道)。
	var m map[string]any
	_ = json.Unmarshal(cfg, &m)
	dnsRules, ok := m["dns"].(map[string]any)["rules"].([]any)
	if !ok || len(dnsRules) == 0 {
		t.Fatalf("split on should have dns.rules (geosite-cn→local), got %v", m["dns"])
	}
	dr := dnsRules[0].(map[string]any)
	if dr["server"] != "local" || dr["rule_set"] == nil {
		t.Errorf("dns rule should route geosite-cn → local, got %v", dr)
	}

	// 关闭分流 → 无 rule_set,且 DNS 无分流规则(全量 remote)。
	cfg2, _ := BuildClientConfig(testNode(), "uuid-1", "k", ClientConfigOpts{})
	if _, ok := routeOf(t, cfg2)["rule_set"]; ok {
		t.Error("split off should have no rule_set")
	}
	var m2 map[string]any
	_ = json.Unmarshal(cfg2, &m2)
	if _, ok := m2["dns"].(map[string]any)["rules"]; ok {
		t.Error("split off should have no dns.rules")
	}

	// 开启但缺 base → 静默不分流(避免渲染出无效 rule_set URL)。
	cfg3, _ := BuildClientConfig(testNode(), "uuid-1", "k", ClientConfigOpts{SplitCN: true})
	if _, ok := routeOf(t, cfg3)["rule_set"]; ok {
		t.Error("split with empty base should have no rule_set")
	}
}

func TestBuildClientConfigPrivateSplit(t *testing.T) {
	domains := []string{"nas.yanmeiai.com", "git.yanmeiai.com", "win.yanmeiai.com"}
	// 私有分流 + 国内分流同时开:验证规则齐全且顺序正确
	// (LAN 直连 → 私有域名强制走隧道 → 国内直连;私有规则必须在国内直连之前,
	// 否则锚点是国内 IP 会被分流成直连、被 frps 侧安全组限源拦截)。
	cfg, err := BuildClientConfig(testNode(), "uuid-1", "k",
		ClientConfigOpts{SplitCN: true, RulesBaseURL: "http://node:8080",
			PrivateSplitDomains: domains})
	if err != nil {
		t.Fatal(err)
	}
	var m map[string]any
	if err := json.Unmarshal(cfg, &m); err != nil {
		t.Fatal(err)
	}

	// ① dns.servers 含系统解析器(type=local):在家吃到局域网 DNS 覆盖(私网IP),
	//    在外用所在网络 DNS 解析出公网锚点。
	dnsm := m["dns"].(map[string]any)
	foundSystem := false
	for _, s := range dnsm["servers"].([]any) {
		sm := s.(map[string]any)
		if sm["tag"] == "dns-system" && sm["type"] == "local" {
			foundSystem = true
		}
	}
	if !foundSystem {
		t.Error("missing dns-system (type=local) dns server")
	}

	// ② dns.rules 首条 = 私有域名→dns-system(须排在 geosite-cn→local 之前)。
	dnsRules := dnsm["rules"].([]any)
	dr := dnsRules[0].(map[string]any)
	if dr["server"] != "dns-system" || dr["domain"] == nil {
		t.Errorf("dns.rules[0] should be private domains → dns-system, got %v", dr)
	}

	// ③ reverse_mapping 开启:应用自行解析后按 IP 连接,回映射补回域名元数据,
	//    路由的 domain 规则才有效。
	if dnsm["reverse_mapping"] != true {
		t.Error("reverse_mapping should be true when private split is on")
	}

	// ④ 路由顺序:LAN 直连 < 私有域名→auto < 国内 rule_set→direct。
	rules := m["route"].(map[string]any)["rules"].([]any)
	lanIdx, privIdx, cnIdx := -1, -1, -1
	for i, r := range rules {
		rm := r.(map[string]any)
		if rm["ip_cidr"] != nil && rm["outbound"] == "direct" {
			lanIdx = i
		}
		if rm["domain"] != nil && rm["outbound"] == "auto" {
			privIdx = i
		}
		if rm["rule_set"] != nil && rm["outbound"] == "direct" {
			cnIdx = i
		}
	}
	if lanIdx < 0 || privIdx < 0 || cnIdx < 0 {
		t.Fatalf("missing rules: lan=%d priv=%d cn=%d", lanIdx, privIdx, cnIdx)
	}
	if !(lanIdx < privIdx && privIdx < cnIdx) {
		t.Errorf("rule order wrong: lan=%d < priv=%d < cn=%d expected", lanIdx, privIdx, cnIdx)
	}

	// ⑤ 不配置 → 全部不出现(行为与旧版完全一致)。
	cfg2, _ := BuildClientConfig(testNode(), "uuid-1", "k", ClientConfigOpts{})
	var m2 map[string]any
	_ = json.Unmarshal(cfg2, &m2)
	dnsm2 := m2["dns"].(map[string]any)
	if _, ok := dnsm2["reverse_mapping"]; ok {
		t.Error("private split off: reverse_mapping should be absent")
	}
	if strings.Contains(string(cfg2), "dns-system") {
		t.Error("private split off: dns-system should be absent")
	}
}

func TestRulesHandler(t *testing.T) {
	dir := t.TempDir()
	if err := os.WriteFile(filepath.Join(dir, "geoip-cn.srs"), []byte("SRS"), 0o644); err != nil {
		t.Fatal(err)
	}
	r := chi.NewRouter()
	r.Get("/v1/rules/{name}", NewRulesHandler(dir).Serve)

	get := func(path string) (int, string) {
		rec := httptest.NewRecorder()
		r.ServeHTTP(rec, httptest.NewRequest("GET", path, nil))
		return rec.Code, rec.Body.String()
	}

	if code, body := get("/v1/rules/geoip-cn.srs"); code != 200 || body != "SRS" {
		t.Fatalf("allowed file: code=%d body=%q, want 200/SRS", code, body)
	}
	if code, _ := get("/v1/rules/passwd"); code != 404 {
		t.Errorf("disallowed name: code=%d, want 404", code)
	}
	if code, _ := get("/v1/rules/geosite-cn.srs"); code != 404 {
		t.Errorf("allowed but missing file: code=%d, want 404", code)
	}
}