package gateway

import (
	"context"
	"net/http"
	"strings"
	"testing"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/auth"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/agent"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/history"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/loop"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
)

// 本文件覆盖 design/22 §7-5 的端到端一半：切换过角色的
// 会话必须保留它曾有过的对话，且模型必须能分辨
// 哪些话语来自更早的角色。这里断言的链条是：
// chat_messages（每消息 persona_id）→ 编排器播种的回合上下文
// → loop 的说话者归属 → 适配器收到的 model.Request。

// requestTexts 按顺序返回 req 每条消息的文本。
func requestTexts(req model.Request) []string {
	out := make([]string, 0, len(req.Messages))
	for _, m := range req.Messages {
		out = append(out, messageTextOf(m))
	}
	return out
}

// messageTextOf 拼接 m 的文本部分。
func messageTextOf(m model.Message) string {
	var b strings.Builder
	for _, c := range m.Content {
		if c.Type == model.ContentTypeText {
			b.WriteString(c.Text)
		}
	}
	return b.String()
}

// TestChatTurnCarriesSpeakerAttributionFromTranscript 是从进程边界验收的
// design/22 §7-5：该会话已持有角色 X 说过的话，它现在
// 绑定到角色 Y，且又来了一个聊天回合。请求必须携带
// X 更早的话语且其说话者归属到 X（不是 Y），原样保留每个
// 已存消息体，并仍以 Y 自己的指令开头。
func TestChatTurnCarriesSpeakerAttributionFromTranscript(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	st := personaTestStore(t)
	reg := personaTestRegistry(t)
	sub, err := st.NewSubSessionFor(ctx, "owner", "yuki")
	if err != nil {
		t.Fatalf("NewSubSessionFor: %v", err)
	}
	// 该会话以 X 说话时的对话原貌，每消息
	// persona id 与编排器持久化的完全一致（design/22 §7-5）。
	for _, m := range []history.Message{
		{SessionID: sub, Role: history.RoleUser, Content: "你还记得吗", PersonaID: "xilian", CreatedAt: 1000},
		{SessionID: sub, Role: history.RoleAssistant, Content: "我记住了，你喜欢冰美式", PersonaID: "xilian", CreatedAt: 1001},
	} {
		if err := st.Append(ctx, m); err != nil {
			t.Fatalf("seed transcript: %v", err)
		}
	}

	ad := &personaAdapter{}
	xilian := gatewayAgentFor(t, "你是昔涟。", ad)
	yuki := gatewayAgentFor(t, "你是由纪。", ad)
	names := map[string]string{"xilian": "昔涟", "yuki": "由纪"}
	l := loop.New(loop.Options{
		Agent:       xilian,
		Agents:      map[string]*agent.Agent{"xilian": xilian, "yuki": yuki},
		PersonaID:   "xilian",
		PersonaName: func(id string) string { return names[id] },
	})
	_, ts, jwt := buildEnv(t, cfgDefault(), Deps{History: st, Personas: reg, Loop: l})
	tok := signAny(t, jwt, "acct", auth.RoleOwner)

	resp, body := doReq(t, http.MethodPost, ts.URL+"/api/v1/chat", map[string]any{"sessionId": sub, "text": "继续"}, tok)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("chat status = %d, want 200 (body=%s)", resp.StatusCode, body)
	}
	if len(ad.reqs) == 0 {
		t.Fatal("the model adapter saw no request")
	}
	req := ad.reqs[len(ad.reqs)-1]

	// 应答角色仍然占据提示词的开头。
	if got := firstSystemText(req); got != "你是由纪。" {
		t.Fatalf("first system = %q, want role Y's prompt", got)
	}

	// X 更早的话语原样抵达了模型（该回合没有
	// 在角色切换处失忆）。
	texts := requestTexts(req)
	xIdx := -1
	for i, txt := range texts {
		if txt == "我记住了，你喜欢冰美式" {
			xIdx = i
			break
		}
	}
	if xIdx < 0 {
		t.Fatalf("X's earlier utterance missing from the request: %q", texts)
	}
	if xIdx == 0 || req.Messages[xIdx].Role == model.RoleSystem {
		t.Fatalf("X's utterance must stay a plain assistant message, got %+v", req.Messages[xIdx])
	}
	if req.Messages[xIdx].SenderName != "xilian" {
		t.Fatalf("speaker label = %q, want xilian (the role that actually spoke it)", req.Messages[xIdx].SenderName)
	}

	// 说话者边界点明 X，并把那一段标记为不是 Y 自己的话。
	note := ""
	for _, m := range req.Messages {
		if m.Role == model.RoleSystem && strings.Contains(messageTextOf(m), "「昔涟」（xilian）") {
			note = messageTextOf(m)
			break
		}
	}
	if note == "" || !strings.Contains(note, "不是你说的") {
		t.Fatalf("no speaker boundary for X found: %q", texts)
	}

	// 没有任何已存消息体被改写，且新发送的用户文本不携带 system
	// 元数据（用户通道保持自由文本，design/11 §10）。
	for _, m := range req.Messages {
		if m.Role != model.RoleUser {
			continue
		}
		if txt := messageTextOf(m); txt != "继续" && txt != "你还记得吗" {
			t.Fatalf("user body = %q, want a stored/verbatim user text", txt)
		}
	}
	if xIdx+1 <= len(req.Messages) && strings.Contains(req.Messages[xIdx].Content[0].Text, "[") {
		t.Fatalf("attribution leaked into X's body: %q", req.Messages[xIdx].Content[0].Text)
	}
}