package loop

import (
	"context"
	"strings"
	"testing"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/capability/restrict"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/agent"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/memory"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
)

// This file locks the multi-character behavior of design/22 §4.2: prompt, memory
// scope, emotion persona and reasoning knobs must all be resolved from the SAME
// per-turn role, so a session can never answer with role Y's voice but role X's
// memory (design/22 §5 风险表 "提示词/情绪/记忆错配").

// personaAgent builds an agent whose instructions name the role, so a test can tell
// which pool entry the loop resolved from the leading system message.
func personaAgent(t *testing.T, instructions string, ad model.Adapter) *agent.Agent {
	t.Helper()
	ag, err := agent.New(instructions, nil, nil, agent.WithModel(ad, nil))
	if err != nil {
		t.Fatalf("agent.New(%q): %v", instructions, err)
	}
	return ag
}

// roleEnv is the environment a session resolver produces for personaID: full-access
// owner identity (the identity lane is unchanged) plus the explicitly bound role.
func roleEnv(personaID string) SessionEnv {
	return SessionEnv{ActorEnv: restrict.ActorOwner, MemWritable: true, PersonaID: personaID}
}

// runPersonaTurn drives one turn for sessionID under env and fails the test on error.
func runPersonaTurn(t *testing.T, l *Loop, env SessionEnv, sessionID, text string) *Result {
	t.Helper()
	res, err := l.Run(WithSessionEnv(context.Background(), env), sessionID, []model.Message{model.TextMessage(model.RoleUser, text)})
	if err != nil {
		t.Fatalf("Run(%s): %v", sessionID, err)
	}
	return res
}

// lastChatRequest returns the newest request the non-streaming path recorded.
func lastChatRequest(t *testing.T, ad *mockAdapter) model.Request {
	t.Helper()
	if len(ad.reqs) == 0 {
		t.Fatal("adapter recorded no request")
	}
	return ad.reqs[len(ad.reqs)-1]
}

// requestContains reports whether any message of req carries want.
func requestContains(req model.Request, want string) bool {
	for _, m := range req.Messages {
		if strings.Contains(messageText(m), want) {
			return true
		}
	}
	return false
}

// TestTurnResolvesSystemPromptFromSessionRole is design/22 acceptance 3: switching a
// session's role switches the identity the model is given. The first system message
// must be the bound role's prompt — that is the whole point of the per-role agent
// pool — while an unbound session and an unknown role both stay on the default role
// instead of failing the turn.
func TestTurnResolvesSystemPromptFromSessionRole(t *testing.T) {
	t.Parallel()
	ad := &mockAdapter{}
	x := personaAgent(t, "你是角色X。", ad)
	y := personaAgent(t, "你是角色Y。", ad)
	l := New(Options{
		Agent:     x,
		Agents:    map[string]*agent.Agent{"X": x, "Y": y},
		PersonaID: "X",
	})

	runPersonaTurn(t, l, roleEnv("Y"), "web:y1", "你好呀")
	req := lastChatRequest(t, ad)
	if got := messageText(req.Messages[0]); got != "你是角色Y。" {
		t.Fatalf("first system message = %q, want the bound role Y's prompt", got)
	}

	// A session with no explicit binding inherits the loop's configured default.
	runPersonaTurn(t, l, roleEnv(""), "web", "你好")
	if got := messageText(lastChatRequest(t, ad).Messages[0]); got != "你是角色X。" {
		t.Fatalf("unbound session prompt = %q, want the default role X's prompt", got)
	}

	// A binding to a role with no pooled agent (deleted/unknown persona) degrades to
	// the default agent rather than erroring.
	runPersonaTurn(t, l, roleEnv("nobody"), "web:z1", "你好")
	if got := messageText(lastChatRequest(t, ad).Messages[0]); got != "你是角色X。" {
		t.Fatalf("unknown role prompt = %q, want the default role X's prompt", got)
	}
}

// TestPersonaScopeMemoryIsolationAndExtraction is design/22 acceptance 2 and 5: the
// memory namespace follows the turn's role, so two sessions bound to different roles
// each recall only their own role's memories while two sessions of the SAME role see
// the same memories (口径 1: memory is persona-scoped, not session-scoped); and the
// extracted item is filed under the role that produced the turn — the regression
// guard for the removal of the extractor's construction-time persona.
func TestPersonaScopeMemoryIsolationAndExtraction(t *testing.T) {
	t.Parallel()
	store := newTestMemoryStore(t)
	ad := &mockAdapter{}
	x := personaAgent(t, "你是角色X。", ad)
	y := personaAgent(t, "你是角色Y。", ad)
	l := New(Options{
		Agent:     x,
		Agents:    map[string]*agent.Agent{"X": x, "Y": y},
		PersonaID: "X",
		Memory:    store,
		Retriever: memory.NewRetriever(store),
		// The extractor is built WITHOUT a persona, exactly as cmd/cyrene builds it:
		// the loop is responsible for stamping the turn's role onto each item.
		Extractor: memory.NewManualExtractor("", memoryOwnerRoleIDForTest),
	})

	runPersonaTurn(t, l, roleEnv("X"), "web:x1", "记住 我喜欢喝乌龙茶")
	runPersonaTurn(t, l, roleEnv("Y"), "web:y1", "记住 我讨厌香菜")

	// Acceptance 5: each extracted memory is filed under the role of its turn.
	byContent := map[string]string{}
	for _, it := range listMemories(t, store) {
		byContent[it.Content] = it.PersonaID
	}
	if got := byContent["我喜欢喝乌龙茶"]; got != "X" {
		t.Fatalf("memory extracted in an X turn is filed under %q, want X (items=%v)", got, byContent)
	}
	if got := byContent["我讨厌香菜"]; got != "Y" {
		t.Fatalf("memory extracted in a Y turn is filed under %q, want Y (items=%v)", got, byContent)
	}

	// Acceptance 2a: the X session recalls X's memory and never Y's.
	runPersonaTurn(t, l, roleEnv("X"), "web:x1", "乌龙茶怎么样")
	req := lastChatRequest(t, ad)
	if !requestContains(req, "我喜欢喝乌龙茶") {
		t.Fatalf("X's turn did not recall X's own memory: %+v", req.Messages)
	}
	if requestContains(req, "我讨厌香菜") {
		t.Fatalf("X's turn leaked Y's memory: %+v", req.Messages)
	}

	// Acceptance 2b: another session of the SAME role sees it too (memory is
	// persona-scoped, so a new session does not start from a blank memory).
	runPersonaTurn(t, l, roleEnv("X"), "web:x2", "乌龙茶怎么样")
	if !requestContains(lastChatRequest(t, ad), "我喜欢喝乌龙茶") {
		t.Fatalf("a second X session did not see X's memory: %+v", lastChatRequest(t, ad).Messages)
	}

	// Acceptance 2c: the Y session recalls only Y's memory.
	runPersonaTurn(t, l, roleEnv("Y"), "web:y1", "香菜怎么样")
	req = lastChatRequest(t, ad)
	if !requestContains(req, "我讨厌香菜") {
		t.Fatalf("Y's turn did not recall Y's own memory: %+v", req.Messages)
	}
	if requestContains(req, "我喜欢喝乌龙茶") {
		t.Fatalf("Y's turn leaked X's memory: %+v", req.Messages)
	}
}

// memoryOwnerRoleIDForTest mirrors the composition root's authoring role id, so the
// test builds the extractor the same way production does.
const memoryOwnerRoleIDForTest = "owner"

// listMemories returns every stored memory item.
func listMemories(t *testing.T, store *memory.Store) []memory.MemoryItem {
	t.Helper()
	items, err := store.List(context.Background())
	if err != nil {
		t.Fatalf("memory list: %v", err)
	}
	return items
}

// frameAdapter streams one thinking frame and one text frame, so a test can assert
// both the request the loop built (thinking knobs) and what it broadcast
// (showToUser gate) on the streaming path.
type frameAdapter struct {
	mockAdapter
}

func (f *frameAdapter) ChatStream(_ context.Context, req model.Request, on func(model.StreamEvent)) (model.Response, error) {
	f.streamReqs = append(f.streamReqs, req)
	if on != nil {
		on(model.StreamEvent{Kind: model.StreamKindThinkingDelta, Delta: "想一下"})
		on(model.StreamEvent{Kind: model.StreamKindTextDelta, Delta: "答案"})
	}
	return model.Response{Content: "答案"}, nil
}

// TestThinkingKnobsFollowTheTurnRole locks the second half of design/22 §4.2: the
// reasoning budget / effort / thinking-broadcast switch that batch A resolved once
// at wiring time must now follow the turn's role, so a session bound to role Y runs
// with Y's budget and Y's broadcast switch instead of the default role's. The
// configured options stay the fallback for an unknown role.
func TestThinkingKnobsFollowTheTurnRole(t *testing.T) {
	t.Parallel()
	ad := &frameAdapter{}
	x := personaAgent(t, "你是角色X。", ad)
	y := personaAgent(t, "你是角色Y。", ad)
	hide := false
	budgetX := &model.Thinking{BudgetTokens: 100}
	knobs := map[string]LoopKnobs{
		"X": {Thinking: budgetX, ReasoningEffort: "high"},
		"Y": {ThinkingShowToUser: &hide},
	}
	var events []model.StreamEvent
	l := New(Options{
		Agent:           x,
		Agents:          map[string]*agent.Agent{"X": x, "Y": y},
		PersonaID:       "X",
		Thinking:        budgetX,
		ReasoningEffort: "high",
		OnStream:        func(ev model.StreamEvent) { events = append(events, ev) },
		PersonaKnobs:    func(personaID string) (LoopKnobs, bool) { k, ok := knobs[personaID]; return k, ok },
	})

	// Role X: its budget reaches the request and its thinking frames are broadcast
	// (showToUser unset = the documented "broadcast as usual").
	runPersonaTurn(t, l, roleEnv("X"), "web:x1", "你好")
	req := ad.streamReqs[len(ad.streamReqs)-1]
	if req.Thinking == nil || req.Thinking.BudgetTokens != 100 {
		t.Fatalf("X's request thinking = %+v, want budget 100", req.Thinking)
	}
	if req.ReasoningEffort != "high" {
		t.Fatalf("X's reasoning effort = %q, want high", req.ReasoningEffort)
	}
	if !hasThinkingFrame(events) {
		t.Fatalf("X's thinking frames were withheld: %+v", events)
	}

	// Role Y: Y configures no budget and hides thinking frames, so Y's request must
	// carry NO thinking directive (the default role's budget must not leak in) and
	// only the text frame may reach the client.
	events = nil
	runPersonaTurn(t, l, roleEnv("Y"), "web:y1", "你好")
	req = ad.streamReqs[len(ad.streamReqs)-1]
	if req.Thinking != nil {
		t.Fatalf("Y's request thinking = %+v, want nil (Y configures none)", req.Thinking)
	}
	if req.ReasoningEffort != "" {
		t.Fatalf("Y's reasoning effort = %q, want empty", req.ReasoningEffort)
	}
	if hasThinkingFrame(events) {
		t.Fatalf("Y's thinking frames were broadcast despite showToUser=false: %+v", events)
	}
	if len(events) == 0 {
		t.Fatal("Y's text frames were suppressed too, want the answer to still stream")
	}

	// An unknown role keeps the loop's configured defaults instead of zeroing them.
	events = nil
	runPersonaTurn(t, l, roleEnv("nobody"), "web:z1", "你好")
	req = ad.streamReqs[len(ad.streamReqs)-1]
	if req.Thinking == nil || req.Thinking.BudgetTokens != 100 {
		t.Fatalf("unknown role thinking = %+v, want the configured default budget", req.Thinking)
	}
	if !hasThinkingFrame(events) {
		t.Fatalf("unknown role thinking frames were withheld: %+v", events)
	}
}

// hasThinkingFrame reports whether the broadcast set carried a reasoning frame.
func hasThinkingFrame(events []model.StreamEvent) bool {
	for _, ev := range events {
		if isThinkingKind(ev.Kind) {
			return true
		}
	}
	return false
}