package kvm2

import (
	"encoding/xml"
	"errors"
	"strings"
	"testing"
	"time"

	"gitea.home.hrajfrisbee.cz/kacerr/egress-proxies-operator/internal/provider"
)

// checkedDomain is an independent view of the marshalled XML, so the tests
// assert on what libvirt would see rather than on the builder's own structs.
type checkedDomain struct {
	Type   string `xml:"type,attr"`
	Name   string `xml:"name"`
	Memory struct {
		Unit  string `xml:"unit,attr"`
		Value int64  `xml:",chardata"`
	} `xml:"memory"`
	VCPU     int32 `xml:"vcpu"`
	Metadata struct {
		Inner string `xml:",innerxml"`
	} `xml:"metadata"`
	OS struct {
		Firmware string `xml:"firmware,attr"`
		Type     struct {
			Arch    string `xml:"arch,attr"`
			Machine string `xml:"machine,attr"`
			Value   string `xml:",chardata"`
		} `xml:"type"`
		FirmwareElems []struct {
			Features []struct {
				Enabled string `xml:"enabled,attr"`
				Name    string `xml:"name,attr"`
			} `xml:"feature"`
		} `xml:"firmware"`
	} `xml:"os"`
	Features struct {
		ACPI []struct{} `xml:"acpi"`
		APIC []struct{} `xml:"apic"`
	} `xml:"features"`
	CPU struct {
		Mode string `xml:"mode,attr"`
	} `xml:"cpu"`
	OnPoweroff string `xml:"on_poweroff"`
	OnReboot   string `xml:"on_reboot"`
	OnCrash    string `xml:"on_crash"`
	Devices    struct {
		Disks []struct {
			Type   string `xml:"type,attr"`
			Device string `xml:"device,attr"`
			Driver struct {
				Name string `xml:"name,attr"`
				Type string `xml:"type,attr"`
			} `xml:"driver"`
			Source struct {
				File string `xml:"file,attr"`
				Pool string `xml:"pool,attr"`
				Vol  string `xml:"volume,attr"`
			} `xml:"source"`
			Target struct {
				Dev string `xml:"dev,attr"`
				Bus string `xml:"bus,attr"`
			} `xml:"target"`
			ReadOnly []struct{} `xml:"readonly"`
		} `xml:"disk"`
		Interfaces []struct {
			Type   string `xml:"type,attr"`
			Source struct {
				Bridge string `xml:"bridge,attr"`
			} `xml:"source"`
			Model struct {
				Type string `xml:"type,attr"`
			} `xml:"model"`
		} `xml:"interface"`
		Serials []struct {
			Type string `xml:"type,attr"`
		} `xml:"serial"`
		Consoles []struct {
			Type   string `xml:"type,attr"`
			Target struct {
				Type string `xml:"type,attr"`
			} `xml:"target"`
		} `xml:"console"`
		Channels []struct {
			Type   string `xml:"type,attr"`
			Target struct {
				Type string `xml:"type,attr"`
				Name string `xml:"name,attr"`
			} `xml:"target"`
		} `xml:"channel"`
		RNGs []struct {
			Model   string `xml:"model,attr"`
			Backend struct {
				Model string `xml:"model,attr"`
				Value string `xml:",chardata"`
			} `xml:"backend"`
		} `xml:"rng"`
		Graphics []struct{} `xml:"graphics"`
	} `xml:"devices"`
}

var testCreatedAt = time.Date(2026, 9, 16, 12, 0, 0, 0, time.UTC)

func testDomainParams() domainParams {
	return domainParams{
		Name:       "proxy-abc",
		UID:        "0b1f9a2e-uid",
		CreatedAt:  testCreatedAt,
		VCPUs:      2,
		MemoryMiB:  2048,
		Firmware:   provider.KVMFirmwareUEFI,
		Bridge:     "br0",
		DiskPath:   "/var/lib/libvirt/images/proxy-abc.qcow2",
		SeedPath:   "/var/lib/libvirt/images/proxy-abc-seed.iso",
		DiskFormat: provider.KVMFormatQcow2,
	}
}

func mustBuildDomain(t *testing.T, p domainParams) (string, checkedDomain) {
	t.Helper()
	out, err := buildDomainXML(p)
	if err != nil {
		t.Fatalf("buildDomainXML: %v", err)
	}
	var d checkedDomain
	if err := xml.Unmarshal([]byte(out), &d); err != nil {
		t.Fatalf("unmarshalling produced XML: %v\n%s", err, out)
	}
	return out, d
}

func TestDomainXML_fileDisksWithResolvedPaths(t *testing.T) {
	t.Parallel()
	p := testDomainParams()
	_, d := mustBuildDomain(t, p)
	if d.Type != "kvm" || d.Name != p.Name {
		t.Errorf("domain type=%q name=%q, want kvm/%s", d.Type, d.Name, p.Name)
	}
	if d.Memory.Unit != "MiB" || d.Memory.Value != p.MemoryMiB || d.VCPU != p.VCPUs {
		t.Errorf("memory=%d %s vcpu=%d, want %d MiB / %d", d.Memory.Value, d.Memory.Unit, d.VCPU, p.MemoryMiB, p.VCPUs)
	}
	if len(d.Devices.Disks) != 2 {
		t.Fatalf("got %d disks, want 2", len(d.Devices.Disks))
	}
	overlay, seed := d.Devices.Disks[0], d.Devices.Disks[1]
	if overlay.Type != "file" || overlay.Device != "disk" {
		t.Errorf("overlay type=%q device=%q, want file/disk", overlay.Type, overlay.Device)
	}
	if overlay.Source.File != p.DiskPath || overlay.Source.Pool != "" || overlay.Source.Vol != "" {
		t.Errorf("overlay source = %+v, want file=%q only", overlay.Source, p.DiskPath)
	}
	if overlay.Driver.Name != "qemu" || overlay.Driver.Type != "qcow2" {
		t.Errorf("overlay driver = %+v, want qemu/qcow2", overlay.Driver)
	}
	if overlay.Target.Dev != "vda" || overlay.Target.Bus != "virtio" {
		t.Errorf("overlay target = %+v, want vda/virtio", overlay.Target)
	}
	if len(overlay.ReadOnly) != 0 {
		t.Error("overlay is readonly")
	}
	if seed.Type != "file" || seed.Device != "cdrom" {
		t.Errorf("seed type=%q device=%q, want file/cdrom", seed.Type, seed.Device)
	}
	if seed.Source.File != p.SeedPath || seed.Source.Pool != "" || seed.Source.Vol != "" {
		t.Errorf("seed source = %+v, want file=%q only", seed.Source, p.SeedPath)
	}
	if seed.Driver.Name != "qemu" || seed.Driver.Type != "raw" {
		t.Errorf("seed driver = %+v, want qemu/raw", seed.Driver)
	}
	if seed.Target.Dev != "sda" || seed.Target.Bus != "sata" {
		t.Errorf("seed target = %+v, want sda/sata", seed.Target)
	}
	if len(seed.ReadOnly) != 1 {
		t.Error("seed is not readonly")
	}
	if d.OnPoweroff != "destroy" || d.OnReboot != "restart" || d.OnCrash != "destroy" {
		t.Errorf("lifecycle actions = %q/%q/%q, want destroy/restart/destroy", d.OnPoweroff, d.OnReboot, d.OnCrash)
	}
}

func TestDomainXML_uefiDefaultSecureBootOff(t *testing.T) {
	t.Parallel()
	_, d := mustBuildDomain(t, testDomainParams())
	if d.OS.Firmware != "efi" {
		t.Errorf(`<os firmware> = %q, want "efi"`, d.OS.Firmware)
	}
	if len(d.OS.FirmwareElems) != 1 {
		t.Fatalf("got %d <firmware> elements, want 1", len(d.OS.FirmwareElems))
	}
	feats := d.OS.FirmwareElems[0].Features
	if len(feats) != 1 || feats[0].Name != "secure-boot" || feats[0].Enabled != "no" {
		t.Errorf("firmware features = %+v, want one secure-boot enabled=no", feats)
	}
	if d.OS.Type.Value != "hvm" {
		t.Errorf("os type = %q, want hvm", d.OS.Type.Value)
	}
}

func TestDomainXML_biosEscape(t *testing.T) {
	t.Parallel()
	p := testDomainParams()
	p.Firmware = provider.KVMFirmwareBIOS
	out, d := mustBuildDomain(t, p)
	if d.OS.Firmware != "" {
		t.Errorf(`<os firmware> = %q, want absent`, d.OS.Firmware)
	}
	if len(d.OS.FirmwareElems) != 0 {
		t.Errorf("got %d <firmware> elements, want none", len(d.OS.FirmwareElems))
	}
	if strings.Contains(out, "firmware") {
		t.Errorf("BIOS domain XML still mentions firmware:\n%s", out)
	}
	if d.OS.Type.Value != "hvm" || d.OS.Type.Machine != "q35" {
		t.Errorf("os type = %+v, want hvm on q35", d.OS.Type)
	}
}

func TestDomainXML_metadataElement(t *testing.T) {
	t.Parallel()
	p := testDomainParams()
	out, d := mustBuildDomain(t, p)
	if !strings.Contains(out, `<instance xmlns="`+metadataURI+`">`) {
		t.Errorf("domain XML lacks the namespaced instance element:\n%s", out)
	}
	m, err := parseInstanceMetadata(d.Metadata.Inner)
	if err != nil {
		t.Fatalf("parseInstanceMetadata(%q): %v", d.Metadata.Inner, err)
	}
	if !m.managed() {
		t.Error("managed() = false, want true")
	}
	if m.UID != p.UID {
		t.Errorf("UID = %q, want %q", m.UID, p.UID)
	}
	if m.CreatedAt != "2026-09-16T12:00:00Z" {
		t.Errorf("CreatedAt = %q, want RFC3339 UTC", m.CreatedAt)
	}
	if !m.createdAt().Equal(p.CreatedAt) {
		t.Errorf("createdAt() = %v, want %v", m.createdAt(), p.CreatedAt)
	}
}

func TestDomainXML_guestAgentChannel(t *testing.T) {
	t.Parallel()
	p := testDomainParams()
	_, d := mustBuildDomain(t, p)
	if len(d.Devices.Channels) != 1 || d.Devices.Channels[0].Type != "unix" ||
		d.Devices.Channels[0].Target.Type != "virtio" || d.Devices.Channels[0].Target.Name != "org.qemu.guest_agent.0" {
		t.Errorf("channels = %+v, want one unix/virtio org.qemu.guest_agent.0", d.Devices.Channels)
	}
	if len(d.Devices.Interfaces) != 1 || d.Devices.Interfaces[0].Type != "bridge" ||
		d.Devices.Interfaces[0].Source.Bridge != p.Bridge || d.Devices.Interfaces[0].Model.Type != "virtio" {
		t.Errorf("interfaces = %+v, want one bridge %s with virtio model", d.Devices.Interfaces, p.Bridge)
	}
	if len(d.Devices.Serials) != 1 || d.Devices.Serials[0].Type != "pty" {
		t.Errorf("serials = %+v, want one pty", d.Devices.Serials)
	}
	if len(d.Devices.Consoles) != 1 || d.Devices.Consoles[0].Type != "pty" || d.Devices.Consoles[0].Target.Type != "serial" {
		t.Errorf("consoles = %+v, want one pty/serial", d.Devices.Consoles)
	}
	if len(d.Devices.RNGs) != 1 || d.Devices.RNGs[0].Model != "virtio" ||
		d.Devices.RNGs[0].Backend.Model != "random" || d.Devices.RNGs[0].Backend.Value != "/dev/urandom" {
		t.Errorf("rngs = %+v, want one virtio random /dev/urandom", d.Devices.RNGs)
	}
	if len(d.Devices.Graphics) != 0 {
		t.Error("domain has <graphics>, want none")
	}
	if d.OS.Type.Arch != "x86_64" || d.OS.Type.Machine != "q35" {
		t.Errorf("os type = %+v, want x86_64/q35", d.OS.Type)
	}
	if d.CPU.Mode != "host-passthrough" {
		t.Errorf("cpu mode = %q, want host-passthrough", d.CPU.Mode)
	}
	if len(d.Features.ACPI) != 1 || len(d.Features.APIC) != 1 {
		t.Errorf("features acpi=%d apic=%d, want one each", len(d.Features.ACPI), len(d.Features.APIC))
	}
}

func TestDomainXML_rejectsBadInput(t *testing.T) {
	t.Parallel()
	tests := []struct {
		name   string
		mutate func(*domainParams)
	}{
		{name: "unknown firmware", mutate: func(p *domainParams) { p.Firmware = "coreboot" }},
		{name: "empty firmware", mutate: func(p *domainParams) { p.Firmware = "" }},
		{name: "empty name", mutate: func(p *domainParams) { p.Name = "" }},
		{name: "empty disk path", mutate: func(p *domainParams) { p.DiskPath = "" }},
		{name: "empty seed path", mutate: func(p *domainParams) { p.SeedPath = "" }},
		{name: "unknown disk format", mutate: func(p *domainParams) { p.DiskFormat = "vmdk" }},
	}
	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			p := testDomainParams()
			tc.mutate(&p)
			out, err := buildDomainXML(p)
			if !errors.Is(err, provider.ErrPermanent) {
				t.Errorf("err = %v, want ErrPermanent", err)
			}
			if out != "" {
				t.Errorf("got XML %q alongside the error", out)
			}
		})
	}
}