package core

import (
	"fmt"
	"net/http"
	"net/http/httptest"
	"strings"
	"sync/atomic"
	"testing"

	"llmsproxy/internal/lua"
)

// readBundledChannels 读内置 channels 插件源（供行为/变异测试共用）。
func readBundledChannels(t *testing.T) (string, error) {
	t.Helper()
	return lua.ReadBundledPlugin("channels")
}

// deviceHarness 是 device-poll 决策表的可复用测试台：假上游（脚本化逐次响应）
// + channels 插件加载指定源码 + minimax 端点指到假上游。
// 行为测试（TestChannelsDevicePollBehavior）与变异测试共用它 —— 决策表只有
// 一份，两处不会漂移。
type deviceHarness struct {
	t    *testing.T
	ps   *lua.Plugins
	ts   *httptest.Server
	step int32
	// script 持续被 HTTP handler 原子读取
	script atomic.Value // []scriptStep
}

type scriptStep struct {
	http int
	body string
}

func newDeviceHarness(t *testing.T, src string) *deviceHarness {
	t.Helper()
	h := &deviceHarness{t: t}
	h.script.Store([]scriptStep{})

	h.ts = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/oauth2/device/code":
			w.Header().Set("Content-Type", "application/json")
			fmt.Fprint(w, `{"device_code":"DEV1","user_code":"ABCD-EFGH","verification_uri":"https://example/activate","interval":1,"expires_in":600}`)
		case "/oauth2/token":
			i := int(atomic.AddInt32(&h.step, 1)) - 1
			script := h.script.Load().([]scriptStep)
			w.Header().Set("Content-Type", "application/json")
			if i >= len(script) {
				w.WriteHeader(500)
				fmt.Fprint(w, `{"error":"unexpected"}`)
				return
			}
			if script[i].http != 0 && script[i].http != 200 {
				w.WriteHeader(script[i].http)
			}
			fmt.Fprint(w, script[i].body)
		default:
			w.WriteHeader(404)
		}
	}))
	t.Cleanup(h.ts.Close)

	c := kernelTestCore(t)
	h.ps = c.Plugins()
	if err := h.ps.LoadSource("channels", src); err != nil {
		t.Fatalf("加载: %v", err)
	}
	if _, err := h.ps.Call("channels", "set_endpoints", map[string]interface{}{
		"platform": "minimax",
		"device": map[string]interface{}{
			"code_url":  h.ts.URL + "/oauth2/device/code",
			"token_url": h.ts.URL + "/oauth2/token",
		},
	}); err != nil {
		t.Fatalf("set_endpoints: %v", err)
	}
	return h
}

// setScript 设置 token 端点的逐次响应脚本。`400 {...}` 形式表示非 200。
func (h *deviceHarness) setScript(steps ...string) {
	var out []scriptStep
	for _, b := range steps {
		code := 200
		switch {
		case strings.HasPrefix(b, "400 "):
			code, b = 400, b[4:]
		case strings.HasPrefix(b, "403 "):
			code, b = 403, b[4:]
		}
		out = append(out, scriptStep{http: code, body: b})
	}
	h.script.Store(out)
	atomic.StoreInt32(&h.step, 0)
}

func (h *deviceHarness) begin() map[string]interface{} {
	out, err := h.ps.InvokeHandler("channels", "start_login", &lua.HandlerRequest{
		Method: "POST", Body: `{"platform":"minimax"}`,
	})
	if err != nil {
		h.t.Fatal(err)
	}
	return out.JSON.(map[string]interface{})
}

func (h *deviceHarness) poll(id string) map[string]interface{} {
	out, _ := h.ps.InvokeHandler("channels", "poll_login", &lua.HandlerRequest{
		Method: "GET", Query: map[string]string{"id": id},
	})
	return out.JSON.(map[string]interface{})
}

// runDecisionTable 跑完整 8 行决策表，全部符合预期返回 true。
// 这是行为契约的单一事实来源：行为测试用它断言通过；变异测试用它杀变异体。
func (h *deviceHarness) runDecisionTable() bool {
	ok := func(cond bool) bool { return cond }
	st := func(steps ...string) map[string]interface{} {
		h.setScript(steps...)
		j := h.begin()
		sid := j["session"].(map[string]interface{})["id"].(string)
		return h.poll(sid)
	}

	// 行1: 200+pending → 等
	if j := st(`{"status":"pending"}`); j["state"] != "pending" {
		return false
	}
	// 行2: 200+slow_down → 等 + interval+5
	h.setScript(`{"status":"slow_down"}`)
	j := h.begin()
	sid := j["session"].(map[string]interface{})["id"].(string)
	if j2 := h.poll(sid); j2["state"] != "pending" {
		return false
	} else if iv, _ := j2["interval"].(float64); iv < 6 {
		return false
	}
	// 行3: 200+denied → failed，message 区分于通用错误（杀"denied 不识别"变异体）
	if j := st(`{"status":"denied"}`); j["state"] != "failed" {
		return false
	} else if msg, _ := j["message"].(string); !strings.Contains(msg, "用户拒绝") {
		return false
	}
	// 行4: 200+expired_token → failed，message 带过期字样
	if j := st(`{"status":"expired_token"}`); j["state"] != "failed" {
		return false
	} else if msg, _ := j["message"].(string); !strings.Contains(msg, "过期") {
		return false
	}
	// 行5: 400+authorization_pending → 等
	if j := st(`400 {"error":"authorization_pending"}`); j["state"] != "pending" {
		return false
	}
	// 行6: 403+slow_down → 等 + interval+5
	h.setScript(`403 {"error":"slow_down"}`)
	j = h.begin()
	sid = j["session"].(map[string]interface{})["id"].(string)
	if j2 := h.poll(sid); j2["state"] != "pending" {
		return false
	} else if iv, _ := j2["interval"].(float64); iv < 6 {
		return false
	}
	// 行7: 200+access_token → completed（需先授权 add_source）
	_ = h.ps.SetPluginKernelPermission("channels", []string{"add_source", "status", "list_sources"}, false)
	h.setScript(`{"access_token":"MM-ACCESS-1","refresh_token":"MM-RF-1","nickname":"mm-user"}`)
	j = h.begin()
	sid = j["session"].(map[string]interface{})["id"].(string)
	if j2 := h.poll(sid); j2["state"] != "completed" || j2["account"] != "mm-user" {
		return false
	}
	// 行8: 其它 error → failed 带文本
	if j := st(`{"error":"server_error"}`); j["state"] != "failed" {
		return false
	}
	return ok(true)
}