package dispatcher

import (
	"context"
	"fmt"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"sync/atomic"
	"testing"
	"time"

	"git.ipao.vip/rogee/go-sip/internal/configread"
	"git.ipao.vip/rogee/go-sip/internal/store"
)

func TestLocalV01RuntimeDiscoveryFailureClosesAdmissionAndStopsTaskConsumers(t *testing.T) {
	var phase atomic.Int32
	var requested []string
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		requested = append(requested, r.URL.RawQuery)
		if r.URL.Path != "/internal/v1/dispatcher/tasks" {
			t.Errorf("unexpected path: %s", r.URL.Path)
			w.WriteHeader(http.StatusNotFound)
			return
		}
		if phase.Load() == 1 {
			w.WriteHeader(http.StatusServiceUnavailable)
			_, _ = w.Write([]byte(`{"schema_version":"task-discovery.v0.4-proposal","resource":"error","error":{"code":"service_unavailable","message":"mock outage"}}`))
			return
		}
		switch r.URL.RawQuery {
		case "mode=snapshot":
			fmt.Fprintf(w, `{"schema_version":"task-discovery.v0.4-proposal","mode":"snapshot","dispatcher_id":%q,"snapshot_id":"22222222-2222-4222-8222-222222222222","watermark":"42","tasks":[{"task_id":%q,"tenant_id":%q,"tenant_key":%q,"status":"running","task_revision":2}],"next_page_token":"page-2"}`, localTestDispatcherID, localTestTaskID, localTestTenantID, localTestTenantKey)
		case "page_token=page-2&snapshot_id=22222222-2222-4222-8222-222222222222":
			fmt.Fprintf(w, `{"schema_version":"task-discovery.v0.4-proposal","mode":"snapshot","dispatcher_id":%q,"snapshot_id":"22222222-2222-4222-8222-222222222222","watermark":"42","tasks":[],"next_page_token":null}`, localTestDispatcherID)
		case "after=42":
			fmt.Fprintf(w, `{"schema_version":"task-discovery.v0.4-proposal","mode":"changes","dispatcher_id":%q,"tasks":[],"next_cursor":"42"}`, localTestDispatcherID)
		default:
			t.Errorf("unexpected discovery query: %q", r.URL.RawQuery)
			w.WriteHeader(http.StatusBadRequest)
		}
	}))
	defer server.Close()
	st, err := store.Open(filepath.Join(t.TempDir(), "dispatcher.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()
	d, err := NewV3(localTestDispatcherID, st, nil, time.Now)
	if err != nil {
		t.Fatal(err)
	}
	client, err := configread.NewClient(server.URL, localTestDispatcherID, "test-secret", server.Client())
	if err != nil {
		t.Fatal(err)
	}
	broker := &fakeQueueBroker{}
	queues := newTaskQueueController(d, broker, nil)
	runtime := &LocalV01Runtime{dispatcher: d, client: client, queues: queues, controls: &localTaskControlProcessor{}}
	if err := runtime.refreshDiscoveryState(context.Background()); err != nil {
		t.Fatal(err)
	}
	if len(requested) != 2 || requested[0] != "mode=snapshot" || requested[1] != "page_token=page-2&snapshot_id=22222222-2222-4222-8222-222222222222" {
		t.Fatalf("snapshot was not fully paginated before admission: %v", requested)
	}
	if err := runtime.catchUpControlBeforeTasks(context.Background()); err != nil {
		t.Fatal(err)
	}
	assignment, err := st.LocalTaskAssignment(localTestDispatcherID, localTestTaskID)
	if err != nil {
		t.Fatal(err)
	}
	if err := queues.StartTask(context.Background(), assignment); err != nil {
		t.Fatal(err)
	}
	phase.Store(1)
	if err := runtime.refreshDiscoveryState(context.Background()); err == nil {
		t.Fatal("outage accepted as fresh discovery")
	}
	var ready int
	if err := st.DB().QueryRow(`SELECT ready FROM local_v04_task_discovery_state WHERE dispatcher_id=?`, localTestDispatcherID).Scan(&ready); err != nil || ready != 0 {
		t.Fatalf("discovery gate after outage=%d err=%v", ready, err)
	}
	select {
	case <-broker.consumers[0].done:
	default:
		t.Fatal("stale task consumer remained active after discovery outage")
	}
	phase.Store(2)
	if err := runtime.refreshDiscoveryState(context.Background()); err != nil {
		t.Fatal(err)
	}
	if len(requested) < 5 || requested[2] != "after=42" || requested[3] != "mode=snapshot" {
		t.Fatalf("outage did not restart a full snapshot: %v", requested)
	}
	if err := runtime.catchUpControlBeforeTasks(context.Background()); err != nil {
		t.Fatal(err)
	}
	if err := st.DB().QueryRow(`SELECT ready FROM local_v04_task_discovery_state WHERE dispatcher_id=?`, localTestDispatcherID).Scan(&ready); err != nil || ready != 1 {
		t.Fatalf("discovery gate after new snapshot=%d err=%v", ready, err)
	}
}

func TestLocalV01RuntimeReconcilesOnlyEligibleAssignments(t *testing.T) {
	now := time.Date(2026, 9, 22, 10, 0, 0, 0, time.UTC)
	d, st, server := newLocalV01TestDispatcher(t, now)
	defer server.Close()
	defer st.Close()
	broker := &fakeQueueBroker{}
	queues := newTaskQueueController(d, broker, nil)
	runtime := &LocalV01Runtime{dispatcher: d, queues: queues}
	if err := runtime.reconcileTaskQueues(context.Background()); err != nil {
		t.Fatal(err)
	}
	if len(broker.started) != 1 || broker.started[0] == "" {
		t.Fatalf("eligible task queue subscriptions=%v", broker.started)
	}
	if err := queues.StopAll(context.Background()); err != nil {
		t.Fatal(err)
	}
}

func TestLocalV01RuntimeReconcileDoesNotConsumePausedAssignment(t *testing.T) {
	now := time.Date(2026, 9, 22, 10, 0, 0, 0, time.UTC)
	d, st, server := newLocalV01TestDispatcher(t, now)
	defer server.Close()
	defer st.Close()
	assignment, err := st.LocalTaskAssignment(localTestDispatcherID, localTestTaskID)
	if err != nil {
		t.Fatal(err)
	}
	assignment, err = st.SetLocalTaskAdmissionBarrier(assignment.DispatcherID, assignment.TaskID, assignment.TenantID, assignment.TenantKey, "paused")
	if err != nil {
		t.Fatal(err)
	}
	broker := &fakeQueueBroker{}
	queues := newTaskQueueController(d, broker, nil)
	runtime := &LocalV01Runtime{dispatcher: d, queues: queues}
	if err := runtime.reconcileTaskQueues(context.Background()); err != nil {
		t.Fatal(err)
	}
	if len(broker.started) != 0 || len(broker.drained) != 0 {
		t.Fatalf("paused task consumed or drained its backlog: started=%v drained=%v", broker.started, broker.drained)
	}
}

func TestTaskAssignmentCanConsumeRequiresRunningAssignedQueue(t *testing.T) {
	base := store.LocalTaskAssignment{
		Status: "running", AdmissionState: "running",
		Queue: store.LocalTaskQueue{QueueName: "saas-owned-queue"},
	}
	cases := []struct {
		name       string
		assignment store.LocalTaskAssignment
		want       bool
	}{
		{name: "eligible", assignment: base, want: true},
		{name: "paused status", assignment: withTaskStatus(base, "paused"), want: false},
		{name: "closed admission", assignment: withAdmissionState(base, "paused"), want: false},
		{name: "removed", assignment: withRemoved(base), want: false},
		{name: "queue missing", assignment: withQueueName(base, ""), want: false},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := taskAssignmentCanConsume(tc.assignment); got != tc.want {
				t.Fatalf("taskAssignmentCanConsume()=%v, want %v", got, tc.want)
			}
		})
	}
}

func TestNewLocalV01RuntimeRequiresDependencies(t *testing.T) {
	if _, err := NewLocalV01Runtime(nil, nil, nil, nil, nil); err == nil {
		t.Fatal("runtime accepted missing dependencies")
	}
}

func TestLocalV01RuntimeRunFailsClosedWhenUnconfigured(t *testing.T) {
	var runtime LocalV01Runtime
	if err := runtime.Run(context.Background()); err == nil {
		t.Fatal("unconfigured runtime started")
	}
}

func withTaskStatus(assignment store.LocalTaskAssignment, status string) store.LocalTaskAssignment {
	assignment.Status = status
	return assignment
}

func withAdmissionState(assignment store.LocalTaskAssignment, state string) store.LocalTaskAssignment {
	assignment.AdmissionState = state
	return assignment
}

func withRemoved(assignment store.LocalTaskAssignment) store.LocalTaskAssignment {
	assignment.Removed = true
	return assignment
}

func withQueueName(assignment store.LocalTaskAssignment, name string) store.LocalTaskAssignment {
	assignment.Queue.QueueName = name
	return assignment
}