// maintenance_dispatch_test.go — exercises Server.DispatchMaintenance
// directly (one Decision at a time). Reuses the same fake-agent
// harness as p2r01_ws_test / repo_ops_test: a real Server with a
// real Hub, plus a websocket connected as the host. We then push
// Decisions through DispatchMaintenance and assert the envelopes
// the agent receives + the job rows that land.
package http

import (
	"context"
	"encoding/json"
	"testing"
	"time"

	"github.com/coder/websocket"
	"github.com/oklog/ulid/v2"

	"gitea.dcglab.co.uk/steve/restic-manager/internal/api"
	"gitea.dcglab.co.uk/steve/restic-manager/internal/server/maintenance"
	"gitea.dcglab.co.uk/steve/restic-manager/internal/store"
)

// readNextCommandRun pulls envelopes until a command.run lands or the
// deadline passes. Returns nil if the deadline is hit.
func readNextCommandRun(t *testing.T, c *websocket.Conn, deadline time.Time) *api.CommandRunPayload {
	t.Helper()
	for time.Now().Before(deadline) {
		ctx, cancel := context.WithTimeout(context.Background(), 600*time.Millisecond)
		mt, raw, err := c.Read(ctx)
		cancel()
		if err != nil {
			return nil
		}
		if mt != websocket.MessageText {
			continue
		}
		var env api.Envelope
		if err := json.Unmarshal(raw, &env); err != nil {
			continue
		}
		if env.Type != api.MsgCommandRun {
			continue
		}
		var p api.CommandRunPayload
		if err := env.UnmarshalPayload(&p); err != nil {
			continue
		}
		return &p
	}
	return nil
}

// TestDispatchMaintenanceSkipsOfflineHosts: host not connected → no
// envelope, no job row.
func TestDispatchMaintenanceSkipsOfflineHosts(t *testing.T) {
	t.Parallel()
	srv, _, st := rawTestServer(t)
	hostID, _ := enrolHostForWS(t, srv, st, "offline-host")

	srv.DispatchMaintenance(context.Background(), []maintenance.Decision{
		{HostID: hostID, Kind: "check", SubsetPct: 10},
	})

	var n int
	if err := st.DB().QueryRow(
		`SELECT COUNT(*) FROM jobs WHERE host_id = ?`, hostID).Scan(&n); err != nil {
		t.Fatalf("count: %v", err)
	}
	if n != 0 {
		t.Errorf("offline host produced %d job rows; want 0", n)
	}
}

// TestDispatchMaintenanceForgetShipsForgetGroups: connected host with
// two source groups (one with retention, one without). Decision of
// kind=forget → command.run with ForgetGroups containing only the
// group that had retention.
func TestDispatchMaintenanceForgetShipsForgetGroups(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServer(t)
	hostID, token := enrolHostForWS(t, srv, st, "forget-host")
	seedInitJob(t, st, hostID)

	keep := 7
	if err := st.CreateSourceGroup(context.Background(), &store.SourceGroup{
		ID: ulid.Make().String(), HostID: hostID, Name: "documents",
		Includes:        []string{"/home/documents"},
		RetentionPolicy: store.RetentionPolicy{KeepLast: &keep},
	}); err != nil {
		t.Fatalf("group docs: %v", err)
	}
	if err := st.CreateSourceGroup(context.Background(), &store.SourceGroup{
		ID: ulid.Make().String(), HostID: hostID, Name: "ephemeral",
		Includes: []string{"/tmp"},
	}); err != nil {
		t.Fatalf("group eph: %v", err)
	}

	c := agentDial(t, srv, ts, hostID, token)
	sendHello(t, c, "forget-host")
	_ = drainUntil(t, c, api.MsgScheduleSet)

	srv.DispatchMaintenance(context.Background(), []maintenance.Decision{
		{HostID: hostID, Kind: "forget"},
	})

	got := readNextCommandRun(t, c, time.Now().Add(2*time.Second))
	if got == nil {
		t.Fatal("no command.run received")
	}
	if got.Kind != api.JobForget {
		t.Errorf("kind: got %q, want %q", got.Kind, api.JobForget)
	}
	if len(got.ForgetGroups) != 1 {
		t.Fatalf("ForgetGroups: got %d entries (%+v), want 1", len(got.ForgetGroups), got.ForgetGroups)
	}
	if got.ForgetGroups[0].Tag != "documents" {
		t.Errorf("forget group tag: got %q, want %q", got.ForgetGroups[0].Tag, "documents")
	}
	if got.ForgetGroups[0].Policy.KeepLast == nil || *got.ForgetGroups[0].Policy.KeepLast != 7 {
		t.Errorf("forget group policy: got %+v", got.ForgetGroups[0].Policy)
	}

	// Job row must be persisted with actor_kind=system.
	var actor string
	if err := st.DB().QueryRow(
		`SELECT actor_kind FROM jobs WHERE host_id = ? AND kind = 'forget'`, hostID).Scan(&actor); err != nil {
		t.Fatalf("query actor_kind: %v", err)
	}
	if actor != "system" {
		t.Errorf("actor_kind: got %q, want system", actor)
	}
}

// TestDispatchMaintenanceForgetSkipsHostWithNoRetention: connected
// host, but every source group has empty retention → no envelope.
func TestDispatchMaintenanceForgetSkipsHostWithNoRetention(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServer(t)
	hostID, token := enrolHostForWS(t, srv, st, "no-ret-host")
	seedInitJob(t, st, hostID)
	if err := st.CreateSourceGroup(context.Background(), &store.SourceGroup{
		ID: ulid.Make().String(), HostID: hostID, Name: "ephemeral",
		Includes: []string{"/tmp"},
	}); err != nil {
		t.Fatalf("group: %v", err)
	}

	c := agentDial(t, srv, ts, hostID, token)
	sendHello(t, c, "no-ret-host")
	_ = drainUntil(t, c, api.MsgScheduleSet)

	srv.DispatchMaintenance(context.Background(), []maintenance.Decision{
		{HostID: hostID, Kind: "forget"},
	})

	if got := readNextCommandRun(t, c, time.Now().Add(800*time.Millisecond)); got != nil {
		t.Errorf("unexpected command.run: %+v", got)
	}
	var n int
	_ = st.DB().QueryRow(`SELECT COUNT(*) FROM jobs WHERE host_id = ? AND kind = 'forget'`, hostID).Scan(&n)
	if n != 0 {
		t.Errorf("forget job rows: got %d, want 0", n)
	}
}

// TestDispatchMaintenancePruneSkipsWithoutAdminCreds: no admin creds
// row → no envelope, no job row, silent skip.
func TestDispatchMaintenancePruneSkipsWithoutAdminCreds(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServer(t)
	hostID, token := enrolHostForWS(t, srv, st, "no-admin-host")
	seedInitJob(t, st, hostID)

	c := agentDial(t, srv, ts, hostID, token)
	sendHello(t, c, "no-admin-host")
	_ = drainUntil(t, c, api.MsgScheduleSet)

	srv.DispatchMaintenance(context.Background(), []maintenance.Decision{
		{HostID: hostID, Kind: "prune"},
	})

	if got := readNextCommandRun(t, c, time.Now().Add(800*time.Millisecond)); got != nil {
		t.Errorf("unexpected command.run: %+v", got)
	}
	var n int
	_ = st.DB().QueryRow(`SELECT COUNT(*) FROM jobs WHERE host_id = ? AND kind = 'prune'`, hostID).Scan(&n)
	if n != 0 {
		t.Errorf("prune job rows: got %d, want 0", n)
	}
}

// TestDispatchMaintenancePruneShipsConfigUpdateThenCommandRun: with
// admin creds set, prune dispatch must push admin config.update first
// then command.run(prune, RequiresAdminCreds=true).
func TestDispatchMaintenancePruneShipsConfigUpdateThenCommandRun(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServer(t)
	hostID, token := enrolHostForWS(t, srv, st, "prune-mt-host")
	setAdminCreds(t, srv, st, hostID)
	seedInitJob(t, st, hostID)

	c := agentDial(t, srv, ts, hostID, token)
	sendHello(t, c, "prune-mt-host")
	_ = drainUntil(t, c, api.MsgScheduleSet)

	srv.DispatchMaintenance(context.Background(), []maintenance.Decision{
		{HostID: hostID, Kind: "prune"},
	})

	// Read until we've seen both config.update(slot=admin) and the
	// prune command.run.
	deadline := time.Now().Add(3 * time.Second)
	var sawAdminPush bool
	var prunePayload *api.CommandRunPayload
	for prunePayload == nil && time.Now().Before(deadline) {
		ctx, cancel := context.WithTimeout(context.Background(), 600*time.Millisecond)
		mt, raw, err := c.Read(ctx)
		cancel()
		if err != nil {
			break
		}
		if mt != websocket.MessageText {
			continue
		}
		var env api.Envelope
		if err := json.Unmarshal(raw, &env); err != nil {
			continue
		}
		switch env.Type {
		case api.MsgConfigUpdate:
			var p api.ConfigUpdatePayload
			if err := env.UnmarshalPayload(&p); err == nil && p.Slot == "admin" {
				sawAdminPush = true
			}
		case api.MsgCommandRun:
			var p api.CommandRunPayload
			if err := env.UnmarshalPayload(&p); err == nil && p.Kind == api.JobPrune {
				cp := p
				prunePayload = &cp
			}
		}
	}
	if !sawAdminPush {
		t.Error("expected config.update(slot=admin) before prune dispatch")
	}
	if prunePayload == nil {
		t.Fatal("timed out waiting for command.run(prune)")
	}
	if !prunePayload.RequiresAdminCreds {
		t.Error("prune command.run must have RequiresAdminCreds=true")
	}

	// Persisted job must be system actor.
	var actor string
	if err := st.DB().QueryRow(
		`SELECT actor_kind FROM jobs WHERE host_id = ? AND kind = 'prune'`, hostID).Scan(&actor); err != nil {
		t.Fatalf("query actor_kind: %v", err)
	}
	if actor != "system" {
		t.Errorf("actor_kind: got %q, want system", actor)
	}
}

// TestDispatchMaintenanceCheckCarriesSubset: Decision SubsetPct=15 →
// command.run.Args == ["15"]. Job row actor_kind=system.
func TestDispatchMaintenanceCheckCarriesSubset(t *testing.T) {
	t.Parallel()
	srv, ts, st := rawTestServer(t)
	hostID, token := enrolHostForWS(t, srv, st, "check-mt-host")
	seedInitJob(t, st, hostID)

	c := agentDial(t, srv, ts, hostID, token)
	sendHello(t, c, "check-mt-host")
	_ = drainUntil(t, c, api.MsgScheduleSet)

	srv.DispatchMaintenance(context.Background(), []maintenance.Decision{
		{HostID: hostID, Kind: "check", SubsetPct: 15},
	})

	got := readNextCommandRun(t, c, time.Now().Add(2*time.Second))
	if got == nil {
		t.Fatal("no command.run received")
	}
	if got.Kind != api.JobCheck {
		t.Errorf("kind: got %q, want %q", got.Kind, api.JobCheck)
	}
	if len(got.Args) != 1 || got.Args[0] != "15" {
		t.Errorf("Args: got %+v, want [15]", got.Args)
	}

	var actor string
	if err := st.DB().QueryRow(
		`SELECT actor_kind FROM jobs WHERE host_id = ? AND kind = 'check'`, hostID).Scan(&actor); err != nil {
		t.Fatalf("query actor_kind: %v", err)
	}
	if actor != "system" {
		t.Errorf("actor_kind: got %q, want system", actor)
	}
}