package e2e

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

// writeE2EPlugin 落一个插件文件到 e2e 的 plugin_dir（SeedBundled 见空目录才
// 落地内置插件，所以先放自定义插件再启动网关）。
func writeE2EPlugin(t *testing.T, dir, name, code string) {
	t.Helper()
	p := filepath.Join(dir, "plugins", name)
	if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p, []byte(code), 0o644); err != nil {
		t.Fatal(err)
	}
}

// e2eConfig 返回一份最小 e2e 配置文本（含 plugin_dir）。
func e2eConfig(dir, listen string) string {
	return "listen: " + listen + "\n" +
		"gateway_keys:\n  - sk-e2e-0001\n" +
		"default_model: AUTO\n" +
		"adapter_dir: " + filepath.Join(dir, "adapters") + "\n" +
		"runtime_file: " + filepath.Join(dir, "runtime.json") + "\n" +
		"plugin_dir: " + filepath.Join(dir, "plugins") + "\n" +
		"sources: []\n"
}

// TestConflictArbitrationE2E（用户要求：服务路径冲突不崩溃不拒启 + WebAPI 裁决）
//
// 真二进制全链路：
//  1. 两个插件声明同一条 /api/plugins/http/ 路径 → 两插件都 loaded，启动正常
//  2. 请求该路径 → 409，错误信息点名两个候选插件（不静默选边）
//  3. GET /api/plugins/conflicts → 列出冲突（路径 + 候选 + 未裁决）
//  4. POST /api/plugins/conflicts 裁决 → 持久化
//  5. 再请求该路径 → 200，赢家应答（{"from":"B"}）
//  6. /v1/models 等既有路由全程不受影响（旧通路无回归）
func TestConflictArbitrationE2E(t *testing.T) {
	bin := buildBinary(t)
	dir := t.TempDir()
	addr := mustAddr(t)

	writeE2EPlugin(t, dir, "plugA.lua", `
local P = {}
P.name = "plugA"
P.version = "1"
P.exports = {}
P.http = { { path = "contested", method = "POST", handler = "h", roles = { "admin" } } }
function P.h(req) return { status = 200, json = { from = "A" } } end
return P
`)
	writeE2EPlugin(t, dir, "plugB.lua", `
local P = {}
P.name = "plugB"
P.version = "1"
P.exports = {}
P.http = { { path = "contested", method = "POST", handler = "h", roles = { "admin" } } }
function P.h(req) return { status = 200, json = { from = "B" } } end
return P
`)

	cfgPath := filepath.Join(dir, "config.yaml")
	if err := os.WriteFile(cfgPath, []byte(e2eConfig(dir, addr)), 0o644); err != nil {
		t.Fatal(err)
	}
	g := startGateway(t, bin, addr, cfgPath)

	// ① 两个插件都加载成功（冲突不拒载）
	resp, body := g.do(http.MethodGet, "/api/plugins", "", true)
	if resp.StatusCode != 200 {
		t.Fatalf("GET /api/plugins: %d %s", resp.StatusCode, body)
	}
	var list struct {
		Plugins []struct {
			Name   string `json:"name"`
			Loaded bool   `json:"loaded"`
		} `json:"plugins"`
	}
	if err := json.Unmarshal([]byte(body), &list); err != nil {
		t.Fatal(err)
	}
	loaded := map[string]bool{}
	for _, p := range list.Plugins {
		loaded[p.Name] = p.Loaded
	}
	if !loaded["plugA"] || !loaded["plugB"] {
		t.Fatalf("冲突的两个插件都应 loaded: %v", loaded)
	}

	// ② 请求冲突路径 → 409 + 点名候选（不静默选边）
	resp, body = g.do(http.MethodPost, "/api/plugins/http/contested", "", true)
	if resp.StatusCode != http.StatusConflict {
		t.Fatalf("未裁决冲突路径应 409, 实得 %d (%s)", resp.StatusCode, body)
	}
	if !strings.Contains(body, "plugA") || !strings.Contains(body, "plugB") {
		t.Fatalf("409 应点名两个候选: %s", body)
	}

	// ③ 冲突列表可见
	resp, body = g.do(http.MethodGet, "/api/plugins/conflicts", "", true)
	if resp.StatusCode != 200 {
		t.Fatalf("GET conflicts: %d %s", resp.StatusCode, body)
	}
	var cl struct {
		Routes []struct {
			Path       string   `json:"path"`
			Candidates []string `json:"candidates"`
			Resolved   string   `json:"resolved"`
		} `json:"routes"`
	}
	if err := json.Unmarshal([]byte(body), &cl); err != nil {
		t.Fatal(err)
	}
	if len(cl.Routes) != 1 || cl.Routes[0].Path != "contested" || cl.Routes[0].Resolved != "" {
		t.Fatalf("冲突形态不对: %+v", cl)
	}

	// ④ 裁决 plugB 赢
	arbit, _ := json.Marshal(map[string]string{
		"kind": "route", "path": "contested", "winner": "plugB",
	})
	resp, body = g.do(http.MethodPost, "/api/plugins/conflicts", string(arbit), true)
	if resp.StatusCode != 200 {
		t.Fatalf("POST conflicts 裁决: %d %s", resp.StatusCode, body)
	}

	// ⑤ 再请求 → 200 且赢家应答
	resp, body = g.do(http.MethodPost, "/api/plugins/http/contested", "", true)
	if resp.StatusCode != 200 {
		t.Fatalf("裁决后请求冲突路径应 200, 实得 %d (%s)", resp.StatusCode, body)
	}
	if !strings.Contains(body, `"from":"B"`) {
		t.Fatalf("赢家 plugB 应答, 实得 %s", body)
	}

	// ⑥ 旧通路无回归：/v1/models 正常
	resp, _ = g.do(http.MethodGet, "/v1/models", "", true)
	if resp.StatusCode != 200 {
		t.Fatalf("旧通路 /v1/models 应 200, 实得 %d", resp.StatusCode)
	}
}

// TestAdapterConflictE2E：插件装与内置同名适配器 → 挂起（现任保留），
// /api/plugins/conflicts 列出，裁决 candidate 后插件版生效。
func TestAdapterConflictE2E(t *testing.T) {
	bin := buildBinary(t)
	dir := t.TempDir()
	addr := mustAddr(t)

	writeE2EPlugin(t, dir, "shadow.lua", `
local P = {}
P.name = "shadow"
P.version = "1"
P.exports = { "install" }
function P.install(args)
  local src = 'local a={} a.name="openai" a.version="SHADOW_V1" a.endpoint="/x" return a'
  local name, err = __llmsproxy_adapters.install("openai", src)
  return { name = name, err = err }
end
return P
`)
	cfgPath := filepath.Join(dir, "config.yaml")
	if err := os.WriteFile(cfgPath, []byte(e2eConfig(dir, addr)), 0o644); err != nil {
		t.Fatal(err)
	}
	g := startGateway(t, bin, addr, cfgPath)

	// ① 安装 → 返回 err（pending 语义），内置版本不变
	resp, body := g.do(http.MethodPost, "/api/plugins/shadow/call/install", "{}", true)
	if resp.StatusCode != 200 {
		t.Fatalf("call install: %d %s", resp.StatusCode, body)
	}
	// Call 端点把插件返回值包在 {"result": …} 里；挂起语义的断言在 result 层做。
	var wrapped struct {
		Result struct {
			Name *string `json:"name"`
			Err  string  `json:"err"`
		} `json:"result"`
	}
	if err := json.Unmarshal([]byte(body), &wrapped); err != nil {
		t.Fatal(err)
	}
	out := wrapped.Result
	if out.Name != nil {
		t.Fatalf("挂起时不得返回生效名: %s", body)
	}
	if !strings.Contains(out.Err, "openai") || !strings.Contains(out.Err, "conflict") {
		t.Fatalf("错误应点名冲突: %q", out.Err)
	}

	// ② 冲突列表可见
	resp, body = g.do(http.MethodGet, "/api/plugins/conflicts", "", true)
	if resp.StatusCode != 200 {
		t.Fatalf("GET conflicts: %d %s", resp.StatusCode, body)
	}
	var cl struct {
		Adapters []struct {
			Name      string `json:"name"`
			Candidate string `json:"candidate"`
		} `json:"adapters"`
	}
	if err := json.Unmarshal([]byte(body), &cl); err != nil {
		t.Fatal(err)
	}
	if len(cl.Adapters) != 1 || cl.Adapters[0].Name != "openai" || cl.Adapters[0].Candidate != "shadow" {
		t.Fatalf("冲突形态不对: %+v", cl)
	}

	// ③ 适配器列表里 openai 仍是内置版本（现任继续服务，不被静默覆盖）
	assertOpenAIVersion := func(want string, msg string) {
		t.Helper()
		resp, body := g.do(http.MethodGet, "/api/adapters", "", true)
		if resp.StatusCode != 200 {
			t.Fatalf("GET /api/adapters: %d %s", resp.StatusCode, body)
		}
		var al struct {
			Adapters []struct {
				Name    string `json:"name"`
				Version string `json:"version"`
			} `json:"adapters"`
		}
		if err := json.Unmarshal([]byte(body), &al); err != nil {
			t.Fatal(err)
		}
		for _, a := range al.Adapters {
			if a.Name == "openai" {
				if a.Version != want {
					t.Fatalf("%s: openai 版本应 %q, 实得 %q", msg, want, a.Version)
				}
				return
			}
		}
		t.Fatalf("%s: openai 适配器不存在: %s", msg, body)
	}
	assertOpenAIVersion("2.0.0", "现任内置必须继续服务（不被静默覆盖）")

	// ④ 裁决 candidate → 插件版生效
	arbit, _ := json.Marshal(map[string]string{
		"kind": "adapter", "name": "openai", "winner": "candidate",
	})
	if resp, body = g.do(http.MethodPost, "/api/plugins/conflicts", string(arbit), true); resp.StatusCode != 200 {
		t.Fatalf("裁决 candidate: %d %s", resp.StatusCode, body)
	}

	// ⑤ 适配器版本已切换 + 冲突清空
	assertOpenAIVersion("SHADOW_V1", "裁决后插件版应生效")
	resp, body = g.do(http.MethodGet, "/api/plugins/conflicts", "", true)
	if resp.StatusCode != 200 {
		t.Fatal(resp.StatusCode)
	}
	if strings.Contains(body, `"name":"openai"`) && strings.Contains(body, `"adapters":[{`) {
		t.Fatalf("裁决后冲突应清除: %s", body)
	}
}