package web

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

	"gitea.dooplex.hu/admin/felhom-controller/internal/agentapi"
	"gitea.dooplex.hu/admin/felhom-controller/internal/settings"
)

// Partitions as places (felhom.eu architecture/16 §6, v0.318.0): the free part of a disk whose other part is a
// registered drive stays on offer; the whole disk never does — in the list AND on the server.

const partMounts = `/dev/mapper/pve-root /mnt/felhom-drives ext4 rw,relatime 0 0
/dev/sdb1 /mnt/felhom-drives/hdd_1 ext4 rw,relatime 0 0
/dev/mapper/pve-vm--9201--disk--1 /mnt/sys_drive ext4 rw,relatime 0 0
`

func diskWithParts() agentapi.DiskCandidate {
	return agentapi.DiskCandidate{Device: "/dev/sdb", MountSource: "/dev/sdb1", FSType: "ext4", DataBearing: true,
		Partitions: []agentapi.CandidatePartition{
			{Device: "/dev/sdb1", Number: 1, FSType: "ext4", State: agentapi.PartInUse, MountedAt: "/mnt/felhom-drives/hdd_1"},
			{Device: "/dev/sdb2", Number: 2, State: agentapi.PartEmpty},
			{Device: "/dev/sdb3", Number: 3, FSType: "ext4", State: agentapi.PartFilesystem, Mountable: true, DurableID: "uuid:3333"},
		}}
}

func TestPartitions_FreePartsOfAnInUseDiskStayOffered(t *testing.T) {
	reg := map[string]bool{"/mnt/felhom-drives/hdd_1": true}
	got := dropRegisteredDrives(agentapi.CandidatesResult{Initialize: []agentapi.DiskCandidate{diskWithParts()}}, partMounts, reg)
	if len(got.Initialize) != 1 {
		t.Fatalf("the disk must stay listed for its free parts, got %+v", got.Initialize)
	}
	c := got.Initialize[0]
	if !c.WholeDiskInUse {
		t.Fatalf("the whole disk must be marked in use (no whole-disk action): %+v", c)
	}
	if len(c.Partitions) != 2 || c.Partitions[0].Device != "/dev/sdb2" || c.Partitions[1].Device != "/dev/sdb3" {
		t.Fatalf("only the free parts may be offered, got %+v", c.Partitions)
	}
}

// R-542 unchanged: a disk with nothing free is still dropped.
func TestPartitions_InUseDiskWithNoFreePartIsDropped(t *testing.T) {
	d := diskWithParts()
	d.Partitions = d.Partitions[:1]
	got := dropRegisteredDrives(agentapi.CandidatesResult{Initialize: []agentapi.DiskCandidate{d}}, partMounts, map[string]bool{"/mnt/felhom-drives/hdd_1": true})
	if len(got.Initialize) != 0 {
		t.Fatalf("a disk with no free part must not be offered, got %+v", got.Initialize)
	}
}

func TestPartitions_ServerRefusesTheWholeDiskButNotTheFreePart(t *testing.T) {
	reg := map[string]bool{"/mnt/felhom-drives/hdd_1": true}
	for dev, want := range map[string]bool{"/dev/sdb": true, "/dev/sdb1": true, "/dev/sdb2": false, "/dev/sdc": false} {
		if got := deviceBacksRegistered(dev, partMounts, reg); got != want {
			t.Errorf("%s: backs a registered drive = %v, want %v", dev, got, want)
		}
	}
	if !deviceBacksRegistered("/dev/sdc", "", reg) {
		t.Errorf("an unreadable mount table must refuse (fail-safe)")
	}
}

func TestPartitions_AFormattedPartsUUIDIsFound(t *testing.T) {
	ag := &mockAgent{candidates: agentapi.CandidatesResult{Initialize: []agentapi.DiskCandidate{diskWithParts()}}}
	if got := resolveEnrollUUID(context.Background(), ag, "/dev/sdb3"); got != "3333" {
		t.Fatalf("the part's new filesystem must be found for the mount, got %q", got)
	}
}

// The handler asks before it starts anything: the whole disk under a registered part → 409, never a format job.
// Positive control: the free part passes the guard and reaches the agent step (503 here: no agent configured).
func TestPartitions_InitHandlerRefusesTheWholeDisk(t *testing.T) {
	s := testServer(t)
	s.mountsFn = func() string { return partMounts }
	if err := s.settings.AddStoragePath(settingsPath("/mnt/felhom-drives/hdd_1")); err != nil {
		t.Fatal(err)
	}
	post := func(dev string) int {
		w := httptest.NewRecorder()
		r := httptest.NewRequest("POST", "/api/storage/init", strings.NewReader(`{"device":"`+dev+`","fstype":"ext4","mount_name":"films"}`))
		s.handleStorageInit(w, r)
		return w.Code
	}
	if c := post("/dev/sdb"); c != http.StatusConflict {
		t.Fatalf("the whole disk under a registered part: want 409, got %d", c)
	}
	if c := post("/dev/sdb2"); c == http.StatusConflict {
		t.Fatalf("positive control: the free part must pass the guard, got %d", c)
	}
}

func settingsPath(p string) settings.StoragePath {
	return settings.StoragePath{Path: p, Schedulable: true}
}