package session

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// TestHTTPProxyClient_GetSession_OK 驗證能正確解析 remote-proxy 的
// /internal/session/:token 回應 → Summary。
func TestHTTPProxyClient_GetSession_OK(t *testing.T) {
	now := time.Now().UTC().Truncate(time.Second)
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, "/internal/session/vAc_abc", r.URL.Path)
		w.Header().Set("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(map[string]any{
			"token":          "vAc_abc",
			"connected":      true,
			"connected_at":   now,
			"last_heartbeat": now,
			"remote_addr":    "1.2.3.4:5678",
			"user_id":        "demo-user",
			"device_id":      "dev-1",
		})
	}))
	defer ts.Close()

	c := NewHTTPProxyClient(ts.URL, nil)
	sum, err := c.GetSession(context.Background(), "vAc_abc")
	require.NoError(t, err)
	require.NotNil(t, sum)
	assert.Equal(t, "vAc_abc", sum.Token)
	assert.Equal(t, "demo-user", sum.UserID)
	assert.Equal(t, "dev-1", sum.DeviceID)
	assert.Equal(t, "1.2.3.4:5678", sum.RemoteAddr)
	assert.True(t, sum.LastHeartbeat.Equal(now))
}

// TestHTTPProxyClient_GetSession_NotFound 驗證 404 → ErrSessionNotFound。
func TestHTTPProxyClient_GetSession_NotFound(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, `{"error":"NOT_FOUND"}`, http.StatusNotFound)
	}))
	defer ts.Close()

	c := NewHTTPProxyClient(ts.URL, nil)
	_, err := c.GetSession(context.Background(), "vAc_xxx")
	assert.ErrorIs(t, err, ErrSessionNotFound)
}

// TestHTTPProxyClient_GetSession_ConnectedFalse_TreatedAsNotFound
// 驗證 remote-proxy 回 connected=false（session 已被排隊清除）→ NotFound。
func TestHTTPProxyClient_GetSession_ConnectedFalse_TreatedAsNotFound(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_ = json.NewEncoder(w).Encode(map[string]any{
			"token":     "vAc_dead",
			"connected": false,
		})
	}))
	defer ts.Close()

	c := NewHTTPProxyClient(ts.URL, nil)
	_, err := c.GetSession(context.Background(), "vAc_dead")
	assert.ErrorIs(t, err, ErrSessionNotFound)
}

// TestHTTPProxyClient_GetSession_EmptyToken 驗證空 token 直接被本地拒絕。
func TestHTTPProxyClient_GetSession_EmptyToken(t *testing.T) {
	c := NewHTTPProxyClient("http://localhost:9999", nil)
	_, err := c.GetSession(context.Background(), "")
	assert.Error(t, err)
}

// TestHTTPProxyClient_ListSessions_OK 驗證能正確 parse sessions array。
func TestHTTPProxyClient_ListSessions_OK(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, "/internal/sessions", r.URL.Path)
		_ = json.NewEncoder(w).Encode(map[string]any{
			"sessions": []map[string]any{
				{"token": "vAc_a", "userId": "u1"},
				{"token": "vAc_b", "userId": "u2"},
			},
			"total": 2,
		})
	}))
	defer ts.Close()

	c := NewHTTPProxyClient(ts.URL, nil)
	sums, err := c.ListSessions(context.Background())
	require.NoError(t, err)
	require.Len(t, sums, 2)
	assert.Equal(t, "vAc_a", sums[0].Token)
}

// TestHTTPProxyClient_ListSessions_Empty 驗證空 sessions 回 non-nil empty slice。
func TestHTTPProxyClient_ListSessions_Empty(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_ = json.NewEncoder(w).Encode(map[string]any{"sessions": nil, "total": 0})
	}))
	defer ts.Close()

	c := NewHTTPProxyClient(ts.URL, nil)
	sums, err := c.ListSessions(context.Background())
	require.NoError(t, err)
	assert.NotNil(t, sums)
	assert.Empty(t, sums)
}

// TestHTTPProxyClient_CloseSession_OK 驗證 200 → nil error。
func TestHTTPProxyClient_CloseSession_OK(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, http.MethodPost, r.Method)
		assert.Equal(t, "/internal/session/vAc_x/close", r.URL.Path)
		_, _ = w.Write([]byte(`{"closed":true}`))
	}))
	defer ts.Close()

	c := NewHTTPProxyClient(ts.URL, nil)
	err := c.CloseSession(context.Background(), "vAc_x")
	assert.NoError(t, err)
}

// TestHTTPProxyClient_CloseSession_NotFound 驗證 404 → ErrSessionNotFound。
func TestHTTPProxyClient_CloseSession_NotFound(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusNotFound)
	}))
	defer ts.Close()

	c := NewHTTPProxyClient(ts.URL, nil)
	err := c.CloseSession(context.Background(), "vAc_x")
	assert.ErrorIs(t, err, ErrSessionNotFound)
}

// TestHTTPProxyClient_BaseURL_TrimsTrailingSlash 驗證 baseURL 結尾的 / 會被移除。
func TestHTTPProxyClient_BaseURL_TrimsTrailingSlash(t *testing.T) {
	c := NewHTTPProxyClient("http://localhost:3801/", nil)
	assert.Equal(t, "http://localhost:3801", c.BaseURL())
}