package weixin_ilink

import (
	"context"
	"errors"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/channel/adapter"
)

// These tests cover the explicit session-rejection state machine (session_state.go):
// iLink answering errcode=-14 must be visible as "re-scan required" instead of a
// silently mute adapter or a connect that reports success with a credential iLink
// already refused.

// rejectingServer answers every getupdates long poll with the rejected-session
// errcode, the way iLink refuses a session credential.
func rejectingServer(t *testing.T) *httptest.Server {
	t.Helper()
	return newJSONServer(t, nil, func(req recordedReq) handlerResult {
		if req.path != "/ilink/bot/getupdates" {
			return handlerResult{status: 404}
		}
		return handlerResult{body: jsonBody(map[string]any{"errcode": errcodeSessionRejected})}
	})
}

// rejectByPoll drives the adapter into the rejected state through the long poll:
// ReadMessages must return on errcode=-14 and the adapter must report the
// rescan-required state.
func rejectByPoll(t *testing.T, ad *Adapter) {
	t.Helper()
	done := make(chan struct{})
	go func() {
		defer close(done)
		ad.ReadMessages(context.Background(), func(adapter.UnifiedMessage) {})
	}()
	waitDone(t, done)
	if required, reason := ad.RescanRequired(); !required || reason == "" {
		t.Fatalf("RescanRequired() = (%v,%q), want (true, non-empty) after errcode=-14", required, reason)
	}
}

// newRejectedByPollAdapter builds a connected adapter and drives it into the
// rejected state via the poll path.
func newRejectedByPollAdapter(t *testing.T, srv *httptest.Server) *Adapter {
	t.Helper()
	ad := newConnectedAdapter(t, Config{BaseURL: srv.URL, PollInterval: time.Millisecond, BotToken: "tok-old"}, srv)
	rejectByPoll(t, ad)
	return ad
}

// assertRejectedSession asserts the observable contract of a session iLink rejected:
// not connected, rescan required with a reason, HealthCheck distinguishing the
// rejected state from not-connected, and Connect refusing with ErrSessionRejected
// instead of a fake OK.
func assertRejectedSession(t *testing.T, ad *Adapter) {
	t.Helper()
	if ad.IsConnected() {
		t.Fatal("IsConnected() = true while iLink rejects the session")
	}
	required, reason := ad.RescanRequired()
	if !required {
		t.Fatal("RescanRequired() = false, want true")
	}
	if reason == "" {
		t.Fatal("RescanRequired() reason is empty, want the re-scan prompt")
	}

	herr := ad.HealthCheck(context.Background())
	if !errors.Is(herr, ErrSessionRejected) {
		t.Fatalf("HealthCheck() = %v, want ErrSessionRejected", herr)
	}
	if errors.Is(herr, adapter.ErrNotConnected) {
		t.Fatal("HealthCheck() also matches ErrNotConnected, want the rejected state to be distinguishable")
	}

	cerr := ad.Connect(context.Background())
	if cerr == nil {
		t.Fatal("Connect() = nil on a rejected session, want ErrSessionRejected (no fake OK)")
	}
	if !errors.Is(cerr, ErrSessionRejected) {
		t.Fatalf("Connect() = %v, want ErrSessionRejected", cerr)
	}
	if errors.Is(cerr, ErrNeedsLogin) {
		t.Fatal("Connect() = ErrNeedsLogin, want ErrSessionRejected (a rejected session is not 'unconfigured')")
	}
	if ad.IsConnected() {
		t.Fatal("IsConnected() = true after a refused Connect on a rejected session")
	}
}

func TestSessionRejected_PollMarksRescanAndRefusesConnect(t *testing.T) {
	t.Parallel()
	srv := rejectingServer(t)
	ad := newRejectedByPollAdapter(t, srv)
	assertRejectedSession(t, ad)
}

func TestSessionRejected_SendMarksRescan(t *testing.T) {
	t.Parallel()
	srv := newJSONServer(t, nil, func(req recordedReq) handlerResult {
		if req.method == http.MethodPost && req.path == "/ilink/bot/sendmessage" {
			return handlerResult{body: jsonBody(map[string]any{"errcode": errcodeSessionRejected})}
		}
		return handlerResult{status: 404}
	})
	ad := newConnectedAdapter(t, Config{BaseURL: srv.URL, BotToken: "tok"}, srv)
	ad.recordInbound("tok-1", adapter.UnifiedMessage{SenderID: "u-1", Timestamp: ad.clock()})

	err := ad.SendMessage(context.Background(), adapter.UnifiedResponse{
		Messages: []adapter.UnifiedMessage{{SenderID: "u-1", Content: "hi"}},
	})
	if !errors.Is(err, ErrSessionRejected) {
		t.Fatalf("SendMessage() = %v, want ErrSessionRejected", err)
	}
	if ad.IsConnected() {
		t.Fatal("IsConnected() = true after a send saw errcode=-14")
	}
	// A later send reports the rejected session itself, not a bare "not connected".
	err = ad.SendMessage(context.Background(), adapter.UnifiedResponse{
		Messages: []adapter.UnifiedMessage{{SenderID: "u-1", Content: "again"}},
	})
	if !errors.Is(err, ErrSessionRejected) {
		t.Fatalf("second SendMessage() = %v, want ErrSessionRejected", err)
	}
	perr := ad.SendProactive(context.Background(), adapter.UnifiedMessage{SenderID: "u-1", Content: "push"})
	if !errors.Is(perr, ErrSessionRejected) {
		t.Fatalf("SendProactive() = %v, want ErrSessionRejected", perr)
	}
	assertRejectedSession(t, ad)
}

func TestSessionRejected_ClearedByScanLogin(t *testing.T) {
	t.Parallel()
	rec := &reqRecorder{}
	srv := newJSONServer(t, rec, func(req recordedReq) handlerResult {
		switch req.path {
		case "/ilink/bot/getupdates":
			return handlerResult{body: jsonBody(map[string]any{"errcode": errcodeSessionRejected})}
		case "/ilink/bot/get_bot_qrcode":
			return handlerResult{body: jsonBody(map[string]any{
				"qrcode": "qr-re", "qrcode_img_content": "https://img/qr",
			})}
		case "/ilink/bot/get_qrcode_status":
			return handlerResult{body: jsonBody(map[string]any{
				"status": "confirmed", "bot_token": "tok-new",
				"ilink_bot_id": "bot-new", "ilink_user_id": "o-1",
			})}
		}
		return handlerResult{status: 404}
	})
	ad := newRejectedByPollAdapter(t, srv)
	assertRejectedSession(t, ad)

	// A rejected token must not short-circuit the scan flow: it is not a usable
	// bind, and ErrAlreadyLoggedIn would leave the owner no way back.
	qr, err := ad.StartLogin(context.Background())
	if err != nil {
		t.Fatalf("StartLogin() on a rejected session = %v, want a fresh QR", err)
	}
	if qr.Qrcode != "qr-re" {
		t.Fatalf("StartLogin() qrcode = %q, want qr-re", qr.Qrcode)
	}

	// The confirmed scan delivers a new token: the rejected state must clear.
	waitFor(t, func() bool { ok, _ := ad.RescanRequired(); return !ok })
	if err := ad.Connect(context.Background()); err != nil {
		t.Fatalf("Connect() after re-scan = %v, want nil", err)
	}
	if !ad.IsConnected() {
		t.Fatal("IsConnected() = false after a confirmed re-scan")
	}
	if err := ad.HealthCheck(context.Background()); err != nil {
		t.Fatalf("HealthCheck() after re-scan = %v, want nil", err)
	}
	if got := ad.Config()["bot_token"]; got != "tok-new" {
		t.Fatalf("bot_token = %v, want tok-new", got)
	}
	if status, _ := ad.LoginStatus(context.Background()); status != LoginStatusConfirmed {
		t.Fatalf("LoginStatus() = %q, want confirmed after a successful re-scan", status)
	}

	// The re-scan asked for a real rebind: the rejected token is not advertised as a
	// local token (that is what invites binded_redirect with no new credentials).
	reqs := rec.find(func(q recordedReq) bool { return q.path == "/ilink/bot/get_bot_qrcode" })
	if len(reqs) != 1 {
		t.Fatalf("get_bot_qrcode requests = %d, want 1", len(reqs))
	}
	if ltl := reqs[0].bodyJSON()["local_token_list"]; ltl == nil {
		t.Fatalf("get_bot_qrcode body has no local_token_list: %s", reqs[0].body)
	} else if list, ok := ltl.([]any); !ok || len(list) != 0 {
		t.Fatalf("get_bot_qrcode local_token_list = %v, want an empty array", ltl)
	}
}

func TestSessionRejected_ClearedByNewToken(t *testing.T) {
	t.Parallel()
	srv := rejectingServer(t)
	ad := newRejectedByPollAdapter(t, srv)

	// The rejected token is still configured: the session stays rejected.
	if err := ad.Connect(context.Background()); !errors.Is(err, ErrSessionRejected) {
		t.Fatalf("Connect() = %v, want ErrSessionRejected while the rejected token is unchanged", err)
	}
	if err := ad.HealthCheck(context.Background()); !errors.Is(err, ErrSessionRejected) {
		t.Fatalf("HealthCheck() = %v, want ErrSessionRejected while the rejected token is unchanged", err)
	}

	setBotToken(ad, "tok-fresh")
	if required, _ := ad.RescanRequired(); required {
		t.Fatal("RescanRequired() = true after a new token was configured")
	}
	if err := ad.Connect(context.Background()); err != nil {
		t.Fatalf("Connect() with a fresh token = %v, want nil", err)
	}
	if !ad.IsConnected() {
		t.Fatal("IsConnected() = false after Connect with a fresh token")
	}
	if err := ad.HealthCheck(context.Background()); err != nil {
		t.Fatalf("HealthCheck() with a fresh token = %v, want nil", err)
	}
}

func TestSessionRejected_LoginStatusReportsRescanAndAllowsRescan(t *testing.T) {
	t.Parallel()
	srv := newJSONServer(t, nil, func(req recordedReq) handlerResult {
		switch req.path {
		case "/ilink/bot/getupdates":
			return handlerResult{body: jsonBody(map[string]any{"errcode": errcodeSessionRejected})}
		case "/ilink/bot/get_bot_qrcode":
			return handlerResult{body: jsonBody(map[string]any{
				"qrcode": "qr-2", "qrcode_img_content": "https://img/qr2",
			})}
		}
		return handlerResult{body: jsonBody(map[string]any{"status": "wait"})}
	})
	ad := newConnectedAdapter(t, Config{
		BaseURL: srv.URL, PollInterval: time.Millisecond,
		LoginInterval: time.Millisecond, LoginTimeout: 30 * time.Millisecond,
		BotToken: "tok-old",
	}, srv)
	rejectByPoll(t, ad)

	// A rejected credential must not read as "confirmed": the panel would re-persist
	// it and call the bind a success.
	status, detail := ad.LoginStatus(context.Background())
	if status != LoginStatusFailed {
		t.Fatalf("LoginStatus() = %q, want failed while iLink rejects the stored token", status)
	}
	if detail == "" {
		t.Fatal("LoginStatus() detail is empty, want the re-scan reason")
	}

	// The panel's 扫码登录 must still mint a QR (ErrAlreadyLoggedIn would block the
	// only recovery path).
	qr, err := ad.StartLogin(context.Background())
	if err != nil {
		t.Fatalf("StartLogin() = %v, want a fresh QR", err)
	}
	if qr.Qrcode != "qr-2" {
		t.Fatalf("StartLogin() qrcode = %q, want qr-2", qr.Qrcode)
	}
	// While the re-scan is in progress its own state is reported, not the rejected one.
	if status, _ := ad.LoginStatus(context.Background()); status != LoginStatusWaiting {
		t.Fatalf("LoginStatus() during the re-scan = %q, want waiting", status)
	}
}

// setBotToken swaps the configured bot token, standing in for a panel save +
// hot reload (which rebuilds the adapter) or any other in-place config refresh;
// the adapter has no public setter because production always constructs a fresh
// instance from the new config.
func setBotToken(ad *Adapter, token string) {
	ad.mu.Lock()
	ad.cfg.BotToken = token
	ad.mu.Unlock()
}