package main

import (
	"encoding/json"
	"net"
	"os"
	"path/filepath"
	"testing"
	"time"
)

func TestRegistryUpdate(t *testing.T) {
	reg := NewRegistry()

	info := SessionInfo{
		PID:       1234,
		SessionID: "sess-1",
		Cwd:       "/home/user/project",
		State:     "Working",
	}

	reg.Update(info)

	list := reg.List()
	if len(list) != 1 {
		t.Fatalf("list len = %d, want 1", len(list))
	}
	if list[0].SessionID != "sess-1" {
		t.Errorf("session_id = %q, want %q", list[0].SessionID, "sess-1")
	}
}

func TestRegistryWaitingSince(t *testing.T) {
	reg := NewRegistry()

	// Session starts Working
	reg.Update(SessionInfo{
		PID:       1234,
		SessionID: "sess-1",
		State:     "Working",
	})

	list := reg.List()
	if list[0].WaitingSince != nil {
		t.Error("WaitingSince should be nil when Working")
	}

	// Session transitions to NeedsInput
	reg.Update(SessionInfo{
		PID:       1234,
		SessionID: "sess-1",
		State:     "Needs Input",
	})

	list = reg.List()
	if list[0].WaitingSince == nil {
		t.Fatal("WaitingSince should be set when NeedsInput")
	}

	waitStart := *list[0].WaitingSince

	// Session goes back to Working -> WaitingSince reset
	reg.Update(SessionInfo{
		PID:       1234,
		SessionID: "sess-1",
		State:     "Working",
	})

	list = reg.List()
	if list[0].WaitingSince != nil {
		t.Errorf("WaitingSince should be nil after returning to Working, got %v", list[0].WaitingSince)
	}

	_ = waitStart
}

func TestRegistryRemoveStale(t *testing.T) {
	reg := NewRegistry()

	reg.Update(SessionInfo{SessionID: "sess-1", State: "Working"})
	reg.Update(SessionInfo{SessionID: "sess-2", State: "Working"})

	// Only sess-1 is still active
	active := map[string]bool{"sess-1": true}
	reg.RemoveStale(active)

	list := reg.List()
	if len(list) != 1 {
		t.Fatalf("list len = %d, want 1", len(list))
	}
	if list[0].SessionID != "sess-1" {
		t.Errorf("session_id = %q, want %q", list[0].SessionID, "sess-1")
	}
}

func TestLabelStoreSetGet(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "labels.json")

	ls, err := NewLabelStore(path)
	if err != nil {
		t.Fatalf("new: %v", err)
	}

	if err := ls.Set("sess-1", "review MR"); err != nil {
		t.Fatalf("set: %v", err)
	}

	got := ls.Get("sess-1")
	if got != "review MR" {
		t.Errorf("get = %q, want %q", got, "review MR")
	}

	// Non-existent key returns empty
	if got := ls.Get("unknown"); got != "" {
		t.Errorf("get unknown = %q, want empty", got)
	}
}

func TestLabelStorePersistence(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "labels.json")

	ls, err := NewLabelStore(path)
	if err != nil {
		t.Fatalf("new: %v", err)
	}
	if err := ls.Set("sess-1", "review MR"); err != nil {
		t.Fatalf("set: %v", err)
	}

	// Create a new LabelStore from the same file
	ls2, err := NewLabelStore(path)
	if err != nil {
		t.Fatalf("new2: %v", err)
	}

	got := ls2.Get("sess-1")
	if got != "review MR" {
		t.Errorf("persisted get = %q, want %q", got, "review MR")
	}
}

func TestLabelStoreLoadMissing(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "nonexistent", "labels.json")

	ls, err := NewLabelStore(path)
	if err != nil {
		t.Fatalf("should not error on missing file: %v", err)
	}

	if got := ls.Get("anything"); got != "" {
		t.Errorf("get = %q, want empty", got)
	}
}

func TestRegistryUpdateTimestamp(t *testing.T) {
	reg := NewRegistry()

	before := time.Now()
	reg.Update(SessionInfo{
		SessionID: "sess-1",
		State:     "Needs Input",
	})
	after := time.Now()

	list := reg.List()
	if list[0].WaitingSince == nil {
		t.Fatal("WaitingSince should be set")
	}
	ws := *list[0].WaitingSince
	if ws.Before(before) || ws.After(after) {
		t.Errorf("WaitingSince %v not between %v and %v", ws, before, after)
	}
}

// sendRequest dials the daemon socket, sends a Request, and decodes the Response.
func sendRequest(t *testing.T, sockPath string, req Request) Response {
	t.Helper()
	conn, err := net.Dial("unix", sockPath)
	if err != nil {
		t.Fatalf("dial: %v", err)
	}
	defer conn.Close()

	if err := json.NewEncoder(conn).Encode(req); err != nil {
		t.Fatalf("encode: %v", err)
	}

	var resp Response
	if err := json.NewDecoder(conn).Decode(&resp); err != nil {
		t.Fatalf("decode: %v", err)
	}
	return resp
}

// newTestDaemon creates a daemon using temp dirs (no real /proc or claude dir).
func newTestDaemon(t *testing.T) *Daemon {
	t.Helper()
	dir := t.TempDir()
	sockPath := filepath.Join(dir, "vmux.sock")
	procDir := filepath.Join(dir, "proc")   // empty, no processes
	claudeDir := filepath.Join(dir, "claude")
	labelsPath := filepath.Join(dir, "labels.json")

	os.MkdirAll(procDir, 0o755)
	os.MkdirAll(claudeDir, 0o755)

	labels, err := NewLabelStore(labelsPath)
	if err != nil {
		t.Fatalf("labels: %v", err)
	}

	return NewDaemon(sockPath, procDir, claudeDir, labels)
}

func TestDaemonStartStop(t *testing.T) {
	d := newTestDaemon(t)

	if err := d.Start(); err != nil {
		t.Fatalf("start: %v", err)
	}

	// Send stop via socket
	resp := sendRequest(t, d.sockPath, Request{Action: "stop"})
	if !resp.OK {
		t.Errorf("stop resp.OK = false, error = %q", resp.Error)
	}

	// Daemon should stop within a short time
	done := make(chan struct{})
	go func() {
		d.Wait()
		close(done)
	}()

	select {
	case <-done:
		// ok
	case <-time.After(2 * time.Second):
		t.Fatal("daemon did not stop within 2s")
	}
}

func TestDaemonListOverSocket(t *testing.T) {
	d := newTestDaemon(t)

	if err := d.Start(); err != nil {
		t.Fatalf("start: %v", err)
	}
	defer d.Stop()

	// Populate registry after Start (initial scan clears unknown sessions)
	d.registry.Update(SessionInfo{
		PID:       42,
		SessionID: "test-sess",
		State:     "Working",
		Cwd:       "/tmp/test",
	})

	resp := sendRequest(t, d.sockPath, Request{Action: "list"})
	if !resp.OK {
		t.Fatalf("list resp.OK = false, error = %q", resp.Error)
	}
	if len(resp.Sessions) != 1 {
		t.Fatalf("sessions len = %d, want 1", len(resp.Sessions))
	}
	if resp.Sessions[0].SessionID != "test-sess" {
		t.Errorf("session_id = %q, want %q", resp.Sessions[0].SessionID, "test-sess")
	}
}

func TestDaemonLabelOverSocket(t *testing.T) {
	d := newTestDaemon(t)

	if err := d.Start(); err != nil {
		t.Fatalf("start: %v", err)
	}
	defer d.Stop()

	// Populate registry after Start (initial scan clears unknown sessions)
	d.registry.Update(SessionInfo{
		PID:       42,
		SessionID: "test-sess",
		State:     "Working",
		Cwd:       "/tmp/test",
	})

	// Set label
	args, _ := json.Marshal(LabelArgs{SessionID: "test-sess", Label: "review MR"})
	resp := sendRequest(t, d.sockPath, Request{Action: "label", Args: args})
	if !resp.OK {
		t.Fatalf("label resp.OK = false, error = %q", resp.Error)
	}

	// Verify label appears in list
	resp = sendRequest(t, d.sockPath, Request{Action: "list"})
	if !resp.OK {
		t.Fatalf("list resp.OK = false, error = %q", resp.Error)
	}
	if len(resp.Sessions) != 1 {
		t.Fatalf("sessions len = %d, want 1", len(resp.Sessions))
	}
	if resp.Sessions[0].Label != "review MR" {
		t.Errorf("label = %q, want %q", resp.Sessions[0].Label, "review MR")
	}
}

func TestDaemonUnknownAction(t *testing.T) {
	d := newTestDaemon(t)

	if err := d.Start(); err != nil {
		t.Fatalf("start: %v", err)
	}
	defer d.Stop()

	resp := sendRequest(t, d.sockPath, Request{Action: "bogus"})
	if resp.OK {
		t.Error("expected OK=false for unknown action")
	}
	if resp.Error == "" {
		t.Error("expected error message for unknown action")
	}
}