package weixin_ilink

import (
	"bytes"
	"context"
	"io"
	"net/http"
	"sync"
	"testing"
	"time"
)

// scriptedTransport answers the weixin_ilink endpoints without network I/O. It
// records the host each get_qrcode_status poll hits so tests can assert the IDC
// redirect routing, and returns get_bot_qrcode with a fixed QR plus get_qrcode_status
// bodies from statusFn (n is the 1-based poll count).
type scriptedTransport struct {
	qr          []byte
	statusFn    func(n int) []byte
	mu          sync.Mutex
	statusHosts []string
}

func (t *scriptedTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	var body []byte
	switch req.URL.Path {
	case "/ilink/bot/get_bot_qrcode":
		body = t.qr
	case "/ilink/bot/get_qrcode_status":
		t.mu.Lock()
		n := len(t.statusHosts) + 1
		t.statusHosts = append(t.statusHosts, req.URL.Host)
		t.mu.Unlock()
		body = t.statusFn(n)
	default:
		return &http.Response{
			StatusCode: http.StatusNotFound,
			Body:       io.NopCloser(bytes.NewReader(nil)),
			Header:     http.Header{},
			Request:    req,
		}, nil
	}
	return &http.Response{
		StatusCode: http.StatusOK,
		Body:       io.NopCloser(bytes.NewReader(body)),
		Header:     http.Header{"Content-Type": []string{"application/json"}},
		Request:    req,
	}, nil
}

func (t *scriptedTransport) hosts() []string {
	t.mu.Lock()
	defer t.mu.Unlock()
	return append([]string(nil), t.statusHosts...)
}

// newScriptedAdapter builds an Adapter wired to a scripted transport (no real
// network), with a base URL that does not resolve — the transport intercepts it.
func newScriptedAdapter(cfg Config, tr http.RoundTripper) (*Adapter, error) {
	return New(cfg, &http.Client{Transport: tr}, nil)
}

const scriptedQR = `{"qrcode":"qr-r","qrcode_img_content":"https://img/r"}`
const scriptedBaseURL = "https://ilinkai.weixin.qq.com"

// TestStartLogin_ScanButRedirectRoutesPoll verifies that a scaned_but_redirect
// response with a redirect_host switches subsequent get_qrcode_status polls to
// the https://<redirect_host> IDC host.
func TestStartLogin_ScanButRedirectRoutesPoll(t *testing.T) {
	t.Parallel()
	tr := &scriptedTransport{
		qr: []byte(scriptedQR),
		statusFn: func(n int) []byte {
			if n == 1 {
				return []byte(`{"status":"scaned_but_redirect","redirect_host":"idc.weixin.qq.com"}`)
			}
			return []byte(`{"status":"confirmed","bot_token":"tok-x","ilink_bot_id":"bot-x","ilink_user_id":"o-1","baseurl":"https://ilinkai.weixin.qq.com"}`)
		},
	}
	ad, err := newScriptedAdapter(Config{
		BaseURL: scriptedBaseURL, LoginInterval: time.Millisecond, LoginTimeout: 5 * time.Second,
	}, tr)
	if err != nil {
		t.Fatalf("New: %v", err)
	}

	if _, err := ad.StartLogin(context.Background()); err != nil {
		t.Fatalf("StartLogin: %v", err)
	}
	waitFor(t, func() bool {
		s, _ := ad.LoginStatus(context.Background())
		return s == LoginStatusConfirmed
	})
	if got := ad.Config()["bot_token"]; got != "tok-x" {
		t.Fatalf("bot_token = %v, want tok-x", got)
	}
	hosts := tr.hosts()
	if len(hosts) < 2 {
		t.Fatalf("status polls = %d, want >= 2 (first on base, second on redirect host)", len(hosts))
	}
	if hosts[0] != "ilinkai.weixin.qq.com" {
		t.Fatalf("first status poll host = %q, want ilinkai.weixin.qq.com", hosts[0])
	}
	if hosts[1] != "idc.weixin.qq.com" {
		t.Fatalf("second status poll host = %q, want idc.weixin.qq.com (IDC redirect)", hosts[1])
	}
}

// TestStartLogin_VerifyCodeBlocked verifies verify_code_blocked transitions the
// login to failed.
func TestStartLogin_VerifyCodeBlocked(t *testing.T) {
	t.Parallel()
	tr := &scriptedTransport{
		qr:       []byte(scriptedQR),
		statusFn: func(int) []byte { return []byte(`{"status":"verify_code_blocked"}`) },
	}
	ad, err := newScriptedAdapter(Config{
		BaseURL: scriptedBaseURL, LoginInterval: time.Millisecond, LoginTimeout: 2 * time.Second,
	}, tr)
	if err != nil {
		t.Fatalf("New: %v", err)
	}
	if _, err := ad.StartLogin(context.Background()); err != nil {
		t.Fatalf("StartLogin: %v", err)
	}
	waitFor(t, func() bool {
		s, _ := ad.LoginStatus(context.Background())
		return s == LoginStatusFailed
	})
	if ad.IsConnected() {
		t.Fatal("IsConnected() = true after verify_code_blocked")
	}
}

// TestStartLogin_BindedRedirect verifies binded_redirect is treated as already
// bound (LoginStatus confirmed) rather than a failure.
func TestStartLogin_BindedRedirect(t *testing.T) {
	t.Parallel()
	tr := &scriptedTransport{
		qr:       []byte(scriptedQR),
		statusFn: func(int) []byte { return []byte(`{"status":"binded_redirect"}`) },
	}
	ad, err := newScriptedAdapter(Config{
		BaseURL: scriptedBaseURL, LoginInterval: time.Millisecond, LoginTimeout: 2 * time.Second,
	}, tr)
	if err != nil {
		t.Fatalf("New: %v", err)
	}
	if _, err := ad.StartLogin(context.Background()); err != nil {
		t.Fatalf("StartLogin: %v", err)
	}
	waitFor(t, func() bool {
		s, _ := ad.LoginStatus(context.Background())
		return s == LoginStatusConfirmed
	})
	if _, detail := ad.LoginStatus(context.Background()); detail != loginBindedRedirectDetail {
		t.Fatalf("binded_redirect detail = %q, want %q", detail, loginBindedRedirectDetail)
	}
}

// TestStartLogin_NeedVerifyCode verifies need_verifycode surfaces a dedicated
// LoginStatus sub-state with a hint detail, then times out to failed.
func TestStartLogin_NeedVerifyCode(t *testing.T) {
	t.Parallel()
	tr := &scriptedTransport{
		qr:       []byte(scriptedQR),
		statusFn: func(int) []byte { return []byte(`{"status":"need_verifycode"}`) },
	}
	ad, err := newScriptedAdapter(Config{
		BaseURL: scriptedBaseURL, LoginInterval: time.Millisecond, LoginTimeout: 40 * time.Millisecond,
	}, tr)
	if err != nil {
		t.Fatalf("New: %v", err)
	}
	if _, err := ad.StartLogin(context.Background()); err != nil {
		t.Fatalf("StartLogin: %v", err)
	}
	waitFor(t, func() bool {
		s, _ := ad.LoginStatus(context.Background())
		return s == LoginStatusNeedVerifyCode
	})
	if _, detail := ad.LoginStatus(context.Background()); detail != loginNeedVerifyCodeHint {
		t.Fatalf("need_verifycode detail = %q, want %q", detail, loginNeedVerifyCodeHint)
	}
	// Without a verify-code回传 path the flow eventually times out to failed.
	waitFor(t, func() bool {
		s, _ := ad.LoginStatus(context.Background())
		return s == LoginStatusFailed
	})
}