package dr

import (
	"context"
	"testing"

	"gitea.dooplex.hu/admin/felhom-agent/internal/hub"
)

func sampleRecipe() *hub.DRRecipeHostHalf {
	return &hub.DRRecipeHostHalf{
		RecipeVersion: 1,
		Guests:        []hub.DRGuest{{VMID: 9201, Cores: 2, MemoryBytes: 12 << 30, DiskBytes: 32 << 30}},
		PBS:           &hub.DRPBSCoord{RepoID: "felhom-offsite", Namespace: "demo-felhom-01", LatestSnapshotID: "9201"},
		Drives:        []hub.DRDrive{{DurableID: "uuid:abc", MountPath: "/mnt/felhom-drives/photos", Intent: "enrolled", TotalBytes: 500 << 30}},
	}
}

// TestBuildRestorePlan_HostLoss: a host_loss directive + recipe yields per-guest {vmid, archive,
// target, sizing} + per-drive {durable_id → mount} + the offsite PBS coord.
func TestBuildRestorePlan_HostLoss(t *testing.T) {
	dir := &hub.WireRestoreDirective{Mode: "host_loss", VMID: 9201, Archive: "felhom-offsite:backup/ct/9201/2026-07-04T14:55:44Z"}
	plan, ok := BuildRestorePlan(dir, sampleRecipe(), "local-lvm")
	if !ok || plan == nil {
		t.Fatal("host_loss must yield a plan")
	}
	if plan.Mode != "host_loss" || len(plan.Guests) != 1 || len(plan.Drives) != 1 {
		t.Fatalf("plan shape = %+v", plan)
	}
	g := plan.Guests[0]
	if g.VMID != 9201 || g.TargetStorage != "local-lvm" || g.Cores != 2 || g.DiskBytes != 32<<30 {
		t.Errorf("planned guest = %+v", g)
	}
	if g.Archive != dir.Archive {
		t.Errorf("planned guest archive = %q, want the directive's %q", g.Archive, dir.Archive)
	}
	d := plan.Drives[0]
	if d.DurableID != "uuid:abc" || d.ExpectedMount != "/mnt/felhom-drives/photos" {
		t.Errorf("planned drive (durable_id→mount) = %+v", d)
	}
	if plan.PBS == nil || plan.PBS.RepoID != "felhom-offsite" {
		t.Errorf("plan must carry the offsite PBS coord, got %+v", plan.PBS)
	}
}

// TestBuildRestorePlan_NoPlanCases is the red-proof anchor: guest_loss / absent / nil-recipe yield
// NO plan (execute-nothing on the wrong mode). Relaxing the mode gate → the guest_loss case fails.
func TestBuildRestorePlan_NoPlanCases(t *testing.T) {
	if _, ok := BuildRestorePlan(&hub.WireRestoreDirective{Mode: "guest_loss", VMID: 9201}, sampleRecipe(), "local-lvm"); ok {
		t.Error("guest_loss must NOT yield a host-loss plan")
	}
	if _, ok := BuildRestorePlan(nil, sampleRecipe(), "local-lvm"); ok {
		t.Error("absent directive must NOT yield a plan")
	}
	if _, ok := BuildRestorePlan(&hub.WireRestoreDirective{Mode: "host_loss"}, nil, "local-lvm"); ok {
		t.Error("nil recipe must NOT yield a plan")
	}
}

// TestConsumer_SurfacesPlanNeverExecutes: the consumer surfaces the plan on host_loss, consults the
// recipe only then, and clears it otherwise. It has NO restore/destroy dependency (execute-nothing
// is structural — the type literally cannot call a restore).
func TestConsumer_SurfacesPlanNeverExecutes(t *testing.T) {
	recipeCalls := 0
	c := NewConsumer(func(context.Context) *hub.DRRecipeHostHalf { recipeCalls++; return sampleRecipe() }, "local-lvm", nil)
	ds := func(d *hub.WireRestoreDirective) *hub.DesiredStateResponse {
		return &hub.DesiredStateResponse{DesiredState: hub.WireDesiredState{RestoreDirective: d}}
	}

	// non-host_loss → no plan, recipe NOT consulted.
	c.OnDesiredState(context.Background(), ds(&hub.WireRestoreDirective{Mode: "guest_loss"}))
	if c.LastPlan() != nil {
		t.Error("guest_loss set a plan")
	}
	if recipeCalls != 0 {
		t.Errorf("recipe consulted on a non-host_loss directive (%d calls)", recipeCalls)
	}
	// host_loss → plan surfaced, recipe consulted once.
	c.OnDesiredState(context.Background(), ds(&hub.WireRestoreDirective{Mode: "host_loss", VMID: 9201}))
	p := c.LastPlan()
	if p == nil || len(p.Guests) != 1 || p.Guests[0].VMID != 9201 {
		t.Fatalf("host_loss plan = %+v", p)
	}
	if recipeCalls != 1 {
		t.Errorf("recipe calls = %d, want 1", recipeCalls)
	}
	// absent directive clears the plan.
	c.OnDesiredState(context.Background(), ds(nil))
	if c.LastPlan() != nil {
		t.Error("absent directive did not clear the plan")
	}
}