package server

import (
	"net/http"
	"os"
	"path/filepath"
	"testing"
	"time"

	"git-ssh.u1680832.nyat.app/weichen/Agent-System-Backend.git/internal/bus"
	"git-ssh.u1680832.nyat.app/weichen/Agent-System-Backend.git/internal/cmdbus"
	"git-ssh.u1680832.nyat.app/weichen/Agent-System-Backend.git/internal/plugins"
	"git-ssh.u1680832.nyat.app/weichen/Agent-System-Backend.git/internal/profiles"
	"git-ssh.u1680832.nyat.app/weichen/Agent-System-Backend.git/internal/runmgr"
	"git-ssh.u1680832.nyat.app/weichen/Agent-System-Backend.git/internal/runtime"
	"git-ssh.u1680832.nyat.app/weichen/Agent-System-Backend.git/internal/settings"
	"git-ssh.u1680832.nyat.app/weichen/Agent-System-Backend.git/internal/store"
	"git-ssh.u1680832.nyat.app/weichen/Agent-System-Backend.git/internal/tools"
	core "git-ssh.u1680832.nyat.app/weichen/Agent-System-Core.git"
)

// ---- N3 WP3：rewind HTTP 层（happy + busy 409）----

// happy：经 API 回滚被追踪写入，restored/skipped 上抛，文件内容退回。
func TestRewindFilesHTTPHappy(t *testing.T) {
	dir := t.TempDir()
	st, err := store.OpenSQLite(filepath.Join(dir, "test.db"))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { st.Close() })
	_ = st.MergeSettingsScope(store.OwnerDefault, settings.ScopeUser, map[string]any{"runtime": map[string]any{"mock": true}})
	reg := tools.NewRegistry()
	reg.RegisterBuiltin()
	setSvc := settings.NewService(st)
	profSvc := profiles.New(st)
	profSvc.EnsureDefault()
	mgr := runmgr.New(st, bus.New(), reg, profSvc, setSvc, &runtime.MockRunner{}, &runtime.MockSubagent{}, &runtime.MockRunner{}, &runtime.MockSubagent{})
	ws := t.TempDir()
	mgr.SetWorkspaceRoot(ws)
	ph := plugins.New(st, reg, setSvc, filepath.Join(dir, "plugins"))
	srv := New(st, mgr, reg, profSvc, setSvc, ph)
	srv.Bus = cmdbus.New(st, nil, nil)
	h := srv.Handler()
	_, convID := setupConversation(t, h)
	runID := postMessage(t, h, convID, "写个文件")
	// 等 run 终态（mock run 是异步的；不回等会撞到会话占用 409）。
	deadline := time.Now().Add(2 * time.Second)
	for {
		run, err := st.GetRunByID(runID)
		if err == nil && (run.Status == core.RunCompleted || run.Status == core.RunFailed || run.Status == core.RunCancelled) {
			break
		}
		if time.Now().After(deadline) {
			t.Fatalf("run 未终态：%+v", run)
		}
		time.Sleep(10 * time.Millisecond)
	}

	// 找到用户消息（anchor）并造一条被追踪写入。
	var userMsgID string
	msgs, err := st.ListMessages(convID)
	if err != nil {
		t.Fatal(err)
	}
	for _, m := range msgs {
		if m.Role == core.RoleUser {
			userMsgID = m.ID
		}
	}
	if userMsgID == "" {
		t.Fatal("no user message")
	}
	sandbox := filepath.Join(ws, store.OwnerDefault, convID)
	if err := os.MkdirAll(sandbox, 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(sandbox, "tracked.txt"), []byte("写入后"), 0o644); err != nil {
		t.Fatal(err)
	}
	cpLog, err := mgr.OpenCheckpoints(store.OwnerDefault, convID)
	if err != nil {
		t.Fatal(err)
	}
	if err := cpLog.Record(userMsgID, sandbox, "tracked.txt", []byte("写入前"), true, []byte("写入后")); err != nil {
		t.Fatal(err)
	}

	// run 行已终态与释放会话占用之间有个 settle 窗口（CI 慢机上会撞 409）：
	// 有界重试直到放行。
	var code int
	var out map[string]any
	deadline2 := time.Now().Add(3 * time.Second)
	for {
		code, out = doJSON(t, h, "POST", "/api/conversations/"+convID+"/rewind", map[string]any{"messageId": userMsgID})
		if code != http.StatusConflict {
			break
		}
		if time.Now().After(deadline2) {
			break
		}
		time.Sleep(15 * time.Millisecond)
	}
	if code != http.StatusOK {
		t.Fatalf("rewind status %d: %v", code, out)
	}
	restored, _ := out["restored"].([]any)
	if len(restored) != 1 || restored[0] != "tracked.txt" {
		t.Fatalf("restored: %v", out)
	}
	body, err := os.ReadFile(filepath.Join(sandbox, "tracked.txt"))
	if err != nil || string(body) != "写入前" {
		t.Fatalf("文件未退回：%v %q", err, body)
	}
}

// busy：会话被占时回滚返回 409。
func TestRewindFilesHTTPBusy409(t *testing.T) {
	dir := t.TempDir()
	st, err := store.OpenSQLite(filepath.Join(dir, "test.db"))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { st.Close() })
	_ = st.MergeSettingsScope(store.OwnerDefault, settings.ScopeUser, map[string]any{"runtime": map[string]any{"mock": false}})
	reg := tools.NewRegistry()
	reg.RegisterBuiltin()
	setSvc := settings.NewService(st)
	profSvc := profiles.New(st)
	profSvc.EnsureDefault()
	release := make(chan struct{})
	blocking := blockingRunner{block: make(chan struct{}, 1), release: release}
	defer close(release)
	mgr := runmgr.New(st, bus.New(), reg, profSvc, setSvc, blocking, blocking, &runtime.MockRunner{}, &runtime.MockSubagent{})
	t.Cleanup(mgr.Shutdown)
	ph := plugins.New(st, reg, setSvc, filepath.Join(dir, "plugins"))
	srv := New(st, mgr, reg, profSvc, setSvc, ph)
	srv.Bus = cmdbus.New(st, nil, nil)
	h := srv.Handler()
	_, convID := setupConversation(t, h)
	postMessage(t, h, convID, "先占住")

	var userMsgID string
	msgs, _ := st.ListMessages(convID)
	for _, m := range msgs {
		if m.Role == core.RoleUser {
			userMsgID = m.ID
		}
	}
	code, _ := doJSON(t, h, "POST", "/api/conversations/"+convID+"/rewind", map[string]any{"messageId": userMsgID})
	if code != http.StatusConflict {
		t.Fatalf("busy rewind 应 409，得到 %d", code)
	}
}