package httpapi

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

	"mfd-monitor-agent/internal/status"
)

const testToken = "test-token"

// withToken 为请求 URL 附加鉴权查询参数。
func withToken(path string) string {
	return path + "?token=" + testToken
}

// TestStatusReturnsCachedSnapshot 验证 /status 读取提供者缓存。
func TestStatusReturnsCachedSnapshot(t *testing.T) {
	provider := StaticProvider{Snapshot: status.HostStatus{
		Agent: status.AgentInfo{Version: "test", SnapshotAt: time.Now(), SnapshotStatus: "ok"},
		Host:  status.HostInfo{Hostname: "host-a"},
	}, OK: true}
	server := New(provider, testToken)

	req := httptest.NewRequest(http.MethodGet, withToken("/status"), nil)
	rec := httptest.NewRecorder()
	server.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("status code = %d", rec.Code)
	}
	var got status.HostStatus
	if err := json.NewDecoder(rec.Body).Decode(&got); err != nil {
		t.Fatal(err)
	}
	if got.Host.Hostname != "host-a" {
		t.Fatalf("hostname = %q", got.Host.Hostname)
	}
}

// TestHealthReportsSnapshotMetadata 验证 /health 返回快照元数据。
func TestHealthReportsSnapshotMetadata(t *testing.T) {
	provider := StaticProvider{Snapshot: status.HostStatus{
		Agent: status.AgentInfo{Version: "test", SnapshotAt: time.Unix(10, 0), SnapshotStatus: "partial"},
	}, OK: true}
	server := New(provider, testToken)

	req := httptest.NewRequest(http.MethodGet, withToken("/health"), nil)
	rec := httptest.NewRecorder()
	server.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("status code = %d", rec.Code)
	}
	var got map[string]any
	if err := json.NewDecoder(rec.Body).Decode(&got); err != nil {
		t.Fatal(err)
	}
	if got["snapshot_status"] != "partial" {
		t.Fatalf("health = %+v", got)
	}
}

// TestStatusReturnsServiceUnavailableBeforeSnapshot 验证 /status 不会在请求时实时采集。
func TestStatusReturnsServiceUnavailableBeforeSnapshot(t *testing.T) {
	server := New(StaticProvider{OK: false}, testToken)

	req := httptest.NewRequest(http.MethodGet, withToken("/status"), nil)
	rec := httptest.NewRecorder()
	server.ServeHTTP(rec, req)

	if rec.Code != http.StatusServiceUnavailable {
		t.Fatalf("status code = %d", rec.Code)
	}
}

// TestHealthReturnsStartingBeforeSnapshot 验证 /health 在启动阶段暴露 starting 状态。
func TestHealthReturnsStartingBeforeSnapshot(t *testing.T) {
	server := New(StaticProvider{OK: false}, testToken)

	req := httptest.NewRequest(http.MethodGet, withToken("/health"), nil)
	rec := httptest.NewRecorder()
	server.ServeHTTP(rec, req)

	if rec.Code != http.StatusServiceUnavailable {
		t.Fatalf("status code = %d", rec.Code)
	}
	var got map[string]string
	if err := json.NewDecoder(rec.Body).Decode(&got); err != nil {
		t.Fatal(err)
	}
	if got["status"] != "starting" {
		t.Fatalf("status = %q", got["status"])
	}
}

// TestStatusRejectsNonGET 验证 /status 仅接受 GET 请求。
func TestStatusRejectsNonGET(t *testing.T) {
	server := New(StaticProvider{OK: true}, testToken)

	req := httptest.NewRequest(http.MethodPost, withToken("/status"), nil)
	rec := httptest.NewRecorder()
	server.ServeHTTP(rec, req)

	if rec.Code != http.StatusMethodNotAllowed {
		t.Fatalf("status code = %d", rec.Code)
	}
}

// TestHealthRejectsNonGET 验证 /health 仅接受 GET 请求。
func TestHealthRejectsNonGET(t *testing.T) {
	server := New(StaticProvider{OK: true}, testToken)

	req := httptest.NewRequest(http.MethodPost, withToken("/health"), nil)
	rec := httptest.NewRecorder()
	server.ServeHTTP(rec, req)

	if rec.Code != http.StatusMethodNotAllowed {
		t.Fatalf("status code = %d", rec.Code)
	}
}

// TestMissingTokenReturnsUnauthorized 验证缺少 token 时返回 401。
func TestMissingTokenReturnsUnauthorized(t *testing.T) {
	server := New(StaticProvider{OK: true}, testToken)

	req := httptest.NewRequest(http.MethodGet, "/status", nil)
	rec := httptest.NewRecorder()
	server.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Fatalf("status code = %d", rec.Code)
	}
}

// TestWrongTokenReturnsUnauthorized 验证错误 token 时返回 401。
func TestWrongTokenReturnsUnauthorized(t *testing.T) {
	server := New(StaticProvider{OK: true}, testToken)

	req := httptest.NewRequest(http.MethodGet, "/status?token=wrong", nil)
	rec := httptest.NewRecorder()
	server.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Fatalf("status code = %d", rec.Code)
	}
}