package configread

import (
	"context"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
)

func TestReadAllCurrentTasksContinuesAfterShortPageUntilEmptyPage(t *testing.T) {
	id := "c046b893-8628-4589-ae50-619d049248a6"
	queries := []string{}
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/internal/v1/dispatcher/tasks" {
			t.Errorf("path=%s", r.URL.Path)
		}
		queries = append(queries, r.URL.RawQuery)
		w.Header().Set("Content-Type", "application/json")
		switch r.URL.Query().Get("after") {
		case "":
			_, _ = w.Write([]byte(`{"dispatcher_id":"` + id + `","cursor":"p-1","tasks":[{"task_id":"task-asr","tenant_id":1001,"status":"running","task_revision":1}]}`))
		case "p-1":
			_, _ = w.Write([]byte(`{"dispatcher_id":"` + id + `","cursor":"p-2","tasks":[{"task_id":"task-full","tenant_id":1001,"status":"paused","task_revision":2}]}`))
		case "p-2":
			_, _ = w.Write([]byte(`{"dispatcher_id":"` + id + `","cursor":"p-end","tasks":[]}`))
		default:
			t.Errorf("unexpected cursor %q", r.URL.RawQuery)
		}
	}))
	defer server.Close()
	client, err := NewClient(server.URL, id, "test-secret", server.Client())
	if err != nil {
		t.Fatal(err)
	}
	list, cursor, err := client.ReadAllCurrentTasks(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	if cursor != "p-end" || len(list) != 2 || list[0].TenantID != 1001 || list[1].TaskID != "task-full" || strings.Join(queries, ",") != ",after=p-1,after=p-2" {
		t.Fatalf("short page ended discovery early: cursor=%q tasks=%+v queries=%v", cursor, list, queries)
	}
}

func TestReadCurrentTasksFailClosed(t *testing.T) {
	id := "c046b893-8628-4589-ae50-619d049248a6"
	for _, tc := range []struct {
		name   string
		body   string
		status int
		after  string
	}{
		{"string tenant", `{"dispatcher_id":"` + id + `","cursor":"next","tasks":[{"task_id":"task-a","tenant_id":"1001","status":"running","task_revision":1}]}`, 200, ""},
		{"missing cursor", `{"dispatcher_id":"` + id + `","tasks":[]}`, 200, ""},
		{"old snapshot", `{"dispatcher_id":"` + id + `","cursor":"next","snapshot_id":"old","tasks":[]}`, 200, ""},
		{"wrong owner", `{"dispatcher_id":"c046b893-8628-4589-ae50-619d049248a7","cursor":"next","tasks":[]}`, 200, ""},
		{"same cursor with tasks", `{"dispatcher_id":"` + id + `","cursor":"p-1","tasks":[{"task_id":"task-a","tenant_id":1001,"status":"running","task_revision":1}]}`, 200, "p-1"},
		{"duplicate in page", `{"dispatcher_id":"` + id + `","cursor":"next","tasks":[{"task_id":"task-a","tenant_id":1001,"status":"running","task_revision":1},{"task_id":"task-a","tenant_id":1001,"status":"paused","task_revision":2}]}`, 200, ""},
		{"service unavailable", `{"resource":"error","error":{"code":"unavailable","message":"try later"}}`, 503, ""},
	} {
		t.Run(tc.name, func(t *testing.T) {
			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				w.Header().Set("Content-Type", "application/json")
				w.WriteHeader(tc.status)
				_, _ = w.Write([]byte(tc.body))
			}))
			defer server.Close()
			client, err := NewClient(server.URL, id, "test-secret", server.Client())
			if err != nil {
				t.Fatal(err)
			}
			if _, err := client.ReadCurrentTasks(context.Background(), tc.after); err == nil {
				t.Fatal("unexpectedly accepted invalid discovery page")
			}
		})
	}
}