package memory

import (
	"bytes"
	"context"
	"encoding/json"
	"log/slog"
	"strings"
	"testing"
	"time"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/db"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/memory/projectindex"
)

// newProjectStoreForTest 打开一个隔离的项目索引库并返回其 store。
func newProjectStoreForTest(t *testing.T) *projectindex.Store {
	t.Helper()
	ctx := context.Background()
	projDB, err := db.Open(ctx, ":memory:", testLogger())
	if err != nil {
		t.Fatalf("open project db: %v", err)
	}
	t.Cleanup(func() { _ = projDB.Close() })
	ps, err := projectindex.New(ctx, projDB, testLogger())
	if err != nil {
		t.Fatalf("projectindex.New: %v", err)
	}
	return ps
}

// projectForLogged 报告缓冲里是否存在一条 source=memory/retriever 且 msg 含 want
// 的 JSON 记录。用结构化字段断言，避免依赖文本格式。
func projectForLogged(t *testing.T, buf *bytes.Buffer, want string) bool {
	t.Helper()
	for _, line := range strings.Split(strings.TrimSpace(buf.String()), "\n") {
		if strings.TrimSpace(line) == "" {
			continue
		}
		rec := map[string]any{}
		if err := json.Unmarshal([]byte(line), &rec); err != nil {
			continue
		}
		if rec["source"] != "memory/retriever" {
			continue
		}
		if msg, _ := rec["msg"].(string); strings.Contains(msg, want) {
			return true
		}
	}
	return false
}

// TestRetriever_ProjectFor_LogsLookupFailure 钉住审计 2026-10-05 §7 的静默吞点：
// 项目链接加载失败（项目行不存在 / 存储故障）必须留下带来源的日志，绝不静默按
// 「无项目」返回。这里构造一条 ProjectID 悬空的项目作用域记忆，断言检索器记下一条
// source=memory/retriever 的记录，且命中仍照常返回（加载失败不影响检索）。
func TestRetriever_ProjectFor_LogsLookupFailure(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	ps := newProjectStoreForTest(t)

	ms := newTestStore(t)
	addItem(t, ms, MemoryItem{
		PersonaID: "persona.a", Content: "Alpha 项目事实",
		Scope: ScopeProject, ProjectID: "project.missing", Kind: KindWorldEvent,
	})

	buf := &bytes.Buffer{}
	log := slog.New(slog.NewJSONHandler(buf, &slog.HandlerOptions{Level: slog.LevelDebug}))
	r := NewRetriever(ms, WithProjectIndex(ps), WithRetrieverLogger(log))

	results, err := r.Retrieve(ctx, "persona.a", "Alpha", 10)
	if err != nil {
		t.Fatalf("Retrieve: %v", err)
	}
	if len(results) == 0 {
		t.Fatal("expected a result (a lookup failure must not drop the item)")
	}
	if results[0].Project != nil {
		t.Fatalf("Result.Project = %+v, want nil for a dangling project_id", results[0].Project)
	}
	if !projectForLogged(t, buf, "project link not found") {
		t.Fatalf("缺带来源（source=memory/retriever）的「项目链接加载失败」日志：%q", buf.String())
	}
}

// TestRetriever_ProjectWriteback_MaterializesIndexEntry 钉住审计 2026-10-05 §4 的
// 「project 域记忆 project_id 悬空 / project 表数据为零」：接入项目索引后，写入一条
// 带 ProjectID 的项目作用域记忆会确保项目索引条目存在，使 projectFor 能解析链接
// （模型因此够得着「项目索引 → 项目描述」层级），且只补不覆盖既有 title/desc。
func TestRetriever_ProjectWriteback_MaterializesIndexEntry(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	ps := newProjectStoreForTest(t)
	if err := ps.PutProject(ctx, projectindex.Project{ID: "project.beta", Title: "真实标题", Desc: "真实描述"}); err != nil {
		t.Fatalf("PutProject: %v", err)
	}

	ms := newTestStore(t)
	_ = NewRetriever(ms, WithProjectIndex(ps)) // 把项目索引接到写入路径

	addItem(t, ms, MemoryItem{
		PersonaID: "persona.a", Content: "Alpha 项目事实",
		Scope: ScopeProject, ProjectID: "project.alpha", Kind: KindWorldEvent,
	})
	addItem(t, ms, MemoryItem{
		PersonaID: "persona.a", Content: "Beta 项目事实",
		Scope: ScopeProject, ProjectID: "project.beta", Kind: KindWorldEvent,
	})

	p, err := ps.GetProject(ctx, "project.alpha")
	if err != nil {
		t.Fatalf("project index entry not materialized from memory write: %v", err)
	}
	if p.ID != "project.alpha" {
		t.Fatalf("materialized project id = %q, want project.alpha", p.ID)
	}
	// 只补不覆盖：既有项目的中文标题必须原样保留。
	kept, err := ps.GetProject(ctx, "project.beta")
	if err != nil {
		t.Fatalf("GetProject(beta): %v", err)
	}
	if kept.Title != "真实标题" || kept.Desc != "真实描述" {
		t.Fatalf("EnsureProject clobbered an existing entry: %+v", kept)
	}

	// 端到端：检索命中带出链接的项目。
	r := NewRetriever(ms, WithProjectIndex(ps))
	results, err := r.Retrieve(ctx, "persona.a", "Alpha", 10)
	if err != nil {
		t.Fatalf("Retrieve: %v", err)
	}
	if len(results) == 0 || results[0].Project == nil || results[0].Project.ID != "project.alpha" {
		t.Fatalf("Result.Project = %+v, want the materialized project.alpha", results[0].Project)
	}
}

// TestRetriever_Retrieve_MaterializesDecayWeight 钉住审计 2026-10-05 §7 / design/03
// §2 裁决 Q3：检索命中时把衰减值物化回写 decay_weight（实库曾 388/388 全 1.0）。
func TestRetriever_Retrieve_MaterializesDecayWeight(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	s := newTestStore(t)

	old := time.Now().UTC().Add(-60 * 24 * time.Hour)
	stored := addItem(t, s, MemoryItem{
		PersonaID: "persona.a", Content: "coffee preference", UpdatedAt: old,
		Scope: ScopePersona, Kind: KindRelationship,
	})

	r := NewRetriever(s)
	if _, err := r.Retrieve(ctx, "persona.a", "coffee", 10); err != nil {
		t.Fatalf("Retrieve: %v", err)
	}

	var dw float64
	var updated string
	if err := s.db.QueryRowContext(ctx,
		"SELECT decay_weight, updated_at FROM memory_items WHERE id = ?", stored.ID).Scan(&dw, &updated); err != nil {
		t.Fatalf("read decay_weight: %v", err)
	}
	if dw >= defaultDecayWeight {
		t.Fatalf("decay_weight = %v, want < %v（命中物化的衰减值）", dw, defaultDecayWeight)
	}
	// 命中即使用：updated_at 被推进到本轮，避免下次读把已物化的值再乘一遍。
	if updated == formatTime(old) {
		t.Fatalf("updated_at 未随命中推进：%q", updated)
	}
}

// TestRetriever_Retrieve_ReadOnlyContext_NoDecayWrite 钉住只读隔离（design/03 §5
// 「能查不能写」）：受限（群聊 / 陌生人）检索经 WithoutDecayWriteback 调用时，
// 记忆库零写入。
func TestRetriever_Retrieve_ReadOnlyContext_NoDecayWrite(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	s := newTestStore(t)

	old := time.Now().UTC().Add(-60 * 24 * time.Hour)
	stored := addItem(t, s, MemoryItem{
		PersonaID: "persona.a", Content: "coffee preference", UpdatedAt: old,
		Scope: ScopePersona, Kind: KindRelationship,
	})

	r := NewRetriever(s)
	if _, err := r.Retrieve(WithoutDecayWriteback(ctx), "persona.a", "coffee", 10); err != nil {
		t.Fatalf("Retrieve: %v", err)
	}

	var dw float64
	if err := s.db.QueryRowContext(ctx,
		"SELECT decay_weight FROM memory_items WHERE id = ?", stored.ID).Scan(&dw); err != nil {
		t.Fatalf("read decay_weight: %v", err)
	}
	if dw != defaultDecayWeight {
		t.Fatalf("只读检索写入了 decay_weight = %v, want 保持不变 %v", dw, defaultDecayWeight)
	}
}