package runtime

import (
	"context"
	"path/filepath"
	"strings"
	"testing"

	agentllm "agent-native/runtime/llm"
	agentsession "agent-native/runtime/session"
	"agent-system-backend/internal/ctxasm"
	core "agent-system-core"
)

func textPart(s string) core.Message {
	return core.Message{Role: core.RoleUser, Parts: []core.Part{{Type: core.PartText, Text: s}}}
}

// 指纹只随结构改写变化：正常追加不动，排除/变体切换必动。
func TestContextRevisionStableOnAppendAndChangesOnDivergence(t *testing.T) {
	base := []core.Message{
		{ID: "m1"}, {ID: "m2"},
	}
	r0 := contextRevision(base)
	if r0 != contextRevision(append(append([]core.Message{}, base...), core.Message{ID: "m3"})) {
		t.Fatal("append must not change revision")
	}
	excluded := append([]core.Message{}, base...)
	excluded[1].Excluded = true
	if contextRevision(excluded) == r0 {
		t.Fatal("exclude must change revision")
	}
	variant := append(append([]core.Message{}, base...), core.Message{ID: "m3", VariantGroup: "g1", VariantIndex: 1})
	if contextRevision(variant) == r0 {
		t.Fatal("variant selection must change revision")
	}
}

// 变体切换（重新生成）触发重播种：转录按当前消息库重建，旧候选不再进入上下文。
func TestTranscriptReseedsOnVariantSwitch(t *testing.T) {
	sandbox := t.TempDir()
	hist := []core.Message{
		{ID: "m1", Role: core.RoleUser, Parts: []core.Part{{Type: core.PartText, Text: "写纪要"}}},
		{ID: "m2", Role: core.RoleAssistant, VariantGroup: "g1", VariantIndex: 0, Parts: []core.Part{{Type: core.PartText, Text: "旧候选"}}},
	}
	var requests [][]agentllm.Message
	base := scriptStream(textTurns("新候选", "再来一版"), nil)
	r := &LLMRunner{Stream: func(ctx context.Context, model string, msgs []agentllm.Message, tools []agentllm.ToolDecl, opts agentllm.StreamOptions) <-chan agentllm.Event {
		requests = append(requests, append([]agentllm.Message{}, msgs...))
		return base(ctx, model, msgs, tools, opts)
	}}
	rc := &fakeRunCtx{ctx: context.Background(), sandbox: sandbox,
		prof: core.AgentProfile{Model: core.ModelRoute{Chat: "test-model"}}, history: hist}
	if err := r.Execute(rc); err != nil {
		t.Fatalf("first Execute: %v", err)
	}
	if !strings.Contains(joinReq(requests[0]), "旧候选") {
		t.Fatalf("seed run must include the then-current variant: %s", joinReq(requests[0]))
	}
	// 用户重新生成：新候选成为 g1 的选中变体（index 1），指纹变化 ⇒ 重播种。
	rc.history = append(append([]core.Message{}, hist...),
		core.Message{ID: "m3", Role: core.RoleUser, Parts: []core.Part{{Type: core.PartText, Text: "换一版"}}},
		core.Message{ID: "m4", Role: core.RoleAssistant, VariantGroup: "g1", VariantIndex: 1, Parts: []core.Part{{Type: core.PartText, Text: "新候选"}}},
	)
	if err := r.Execute(rc); err != nil {
		t.Fatalf("second Execute: %v", err)
	}
	sess, err := agentsession.Open(filepath.Join(sandbox, ".agentx", "transcript.jsonl"))
	if err != nil {
		t.Fatal(err)
	}
	loaded, err := sess.Load()
	if err != nil {
		t.Fatal(err)
	}
	joined := ""
	for _, m := range loaded {
		joined += m.Content + "\n"
	}
	if strings.Contains(joined, "旧候选") {
		t.Fatalf("reseed must drop the superseded variant: %s", joined)
	}
	if !strings.Contains(joined, "新候选") {
		t.Fatalf("reseed must keep the selected variant: %s", joined)
	}
}

// 非播种 run 的首个请求注入一次环境刷新与新命中模块；播种 run 不注入
// （系统段已含）。用 JSON 兼容方式探请求文本。
func joinReq(msgs []agentllm.Message) string {
	var b strings.Builder
	for _, m := range msgs {
		b.WriteString(m.Content)
		b.WriteString("\n")
	}
	return b.String()
}

func TestBuildCurrentUserCarriesAttachmentsAndKnowledge(t *testing.T) {
	doc := core.ParsedDocument{
		Meta:   core.DocMeta{Filename: "会议.docx"},
		Blocks: []core.DocBlock{{Type: core.BlockPara, Text: "结论先入库。"}},
	}
	kn := []core.RetrievalHit{{Doc: core.KnowledgeDoc{Title: "知识", Source: "upload", Chunk: "片段"}}}
	got := ctxasm.BuildCurrentUser(core.EffectiveSettings{}, core.Message{Parts: []core.Part{{Type: core.PartText, Text: "总结"}}}, []core.ParsedDocument{doc}, kn, &ctxasm.Report{})
	for _, want := range []string{"总结", "会议.docx", "结论先入库。", "[相关知识]", "片段"} {
		if !strings.Contains(got.Content, want) {
			t.Fatalf("current user missing %q: %s", want, got.Content)
		}
	}
}

var _ = agentllm.Message{}