package accountant

import (
	"encoding/json"
	"io"
	"log/slog"
	"net/http"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"testing"
	"time"

	"sultan/pkg/ledger"
)

var cmkNow = time.Date(2026, 10, 18, 12, 0, 0, 0, time.UTC)

func cmkReport(routes ...ReportRoute) Report {
	return Report{
		GeneratedAt: cmkNow,
		Nodes: []ReportNode{
			{ID: "webdocker11", Tenant: "kunde", Connected: true},
			{ID: "alt", Tenant: "kunde", Connected: false},
			{ID: "wartung", Tenant: "kunde", Connected: false, Maintenance: true},
		},
		Routes: routes,
	}
}

func okRoute(host string) ReportRoute {
	return ReportRoute{Tenant: "kunde", Node: "webdocker11", Workload: "wp", Router: "wp", Protocol: "http",
		Hosts: []string{host}, Backend: "http://10.0.0.11:8081", BackendFQDN: "webdocker11.lan:8081",
		Active: true, ComposeDir: "/srv/kunde-a", Health: "healthy", State: "running"}
}

func findURL(t *testing.T, d CheckmkData, service string) CheckmkURL {
	t.Helper()
	for _, u := range d.URLs {
		if u.Service == service {
			return u
		}
	}
	t.Fatalf("Service %q fehlt in %+v", service, d.URLs)
	return CheckmkURL{}
}

// Zustände: OK, WARN bei Problemen der Route, CRIT bei veraltetem Bericht;
// Wartung dämpft auf OK.
func TestBuildCheckmk_States(t *testing.T) {
	inactive := okRoute("fremd.de")
	inactive.Active = false
	down := okRoute("olat.kunde.de")
	down.Down = true
	sick := okRoute("krank.kunde.de")
	sick.Health = "unhealthy"
	gone := okRoute("weg.kunde.de")
	gone.Node = "alt"
	maint := okRoute("pause.kunde.de")
	maint.Node, maint.Down = "wartung", true
	multi := okRoute("kunde.de")
	multi.Hosts = []string{"kunde.de", "www.kunde.de"}

	payees := []ledger.Payee{
		{ID: "frisch", Hostname: "webproxy11", LastReport: cmkNow.Add(-time.Minute)},
		{ID: "lahm", Hostname: "webproxy12", LastReport: cmkNow.Add(-3 * time.Hour)},
		{ID: "tot", Hostname: "webproxy13", LastReport: cmkNow.Add(-7 * time.Hour)},
		{ID: "neu", Hostname: "webproxy14"},
	}
	reports := map[string]Report{
		"frisch": cmkReport(okRoute("ok.kunde.de"), inactive, down, sick, gone, maint, multi),
		"lahm":   cmkReport(okRoute("lahm.kunde.de")),
		"tot":    cmkReport(okRoute("tot.kunde.de")),
	}
	d := buildCheckmk(payees, reports, cmkNow, 2*time.Hour, 6*time.Hour)

	wantPayees := map[string]int{"frisch": 0, "lahm": 1, "tot": 2, "neu": 1}
	for _, p := range d.Payees {
		if p.State != wantPayees[p.ID] {
			t.Errorf("Payee %s: Status %d, erwartet %d (%+v)", p.ID, p.State, wantPayees[p.ID], p)
		}
	}
	if len(d.Payees) != 4 {
		t.Errorf("Payees: %+v", d.Payees)
	}

	tests := []struct {
		service, problem string
		state            int
	}{
		{"Sultan URL ok.kunde.de", "", 0},
		{"Sultan URL fremd.de", "von Policy verworfen", 1},
		{"Sultan URL olat.kunde.de", "gestoppt", 1},
		{"Sultan URL krank.kunde.de", "unhealthy", 1},
		{"Sultan URL weg.kunde.de", "Knoten getrennt", 1},
		{"Sultan URL pause.kunde.de", "Wartung", 0},
		{"Sultan URL kunde.de", "", 0},
		{"Sultan URL www.kunde.de", "", 0},
		{"Sultan URL lahm.kunde.de", "Bericht", 1},
		{"Sultan URL tot.kunde.de", "Bericht", 2},
	}
	for _, tt := range tests {
		u := findURL(t, d, tt.service)
		if u.State != tt.state || (tt.problem == "") != (u.Problem == "") || !strings.Contains(u.Problem, tt.problem) {
			t.Errorf("%s: Status %d Problem %q, erwartet %d %q", tt.service, u.State, u.Problem, tt.state, tt.problem)
		}
	}
	u := findURL(t, d, "Sultan URL ok.kunde.de")
	if u.URL != "https://ok.kunde.de" || u.BackendURL != "http://webdocker11.lan:8081" || u.Payee != "frisch" ||
		u.Tenant != "kunde" || u.ComposeDir != "/srv/kunde-a" {
		t.Errorf("Felder: %+v", u)
	}
	for i := 1; i < len(d.URLs); i++ {
		if d.URLs[i-1].Service > d.URLs[i].Service {
			t.Errorf("nicht sortiert: %s vor %s", d.URLs[i-1].Service, d.URLs[i].Service)
		}
	}
}

// Derselbe Host zweimal (z. B. zwei Payees): eindeutige Servicenamen.
func TestBuildCheckmk_DuplicateHosts(t *testing.T) {
	payees := []ledger.Payee{{ID: "a", LastReport: cmkNow}, {ID: "b", LastReport: cmkNow}}
	reports := map[string]Report{"a": cmkReport(okRoute("kunde.de")), "b": cmkReport(okRoute("kunde.de"))}
	d := buildCheckmk(payees, reports, cmkNow, 2*time.Hour, 6*time.Hour)
	if len(d.URLs) != 2 || d.URLs[0].Service == d.URLs[1].Service {
		t.Errorf("Servicenamen nicht eindeutig: %+v", d.URLs)
	}
}

// Werte vom Kunden-Host sind Fremdeingaben: einzeilig, ASCII, ohne | und ",
// HTML-escaped; Unescaped nur bereinigt.
func TestBuildCheckmk_Sanitizes(t *testing.T) {
	evil := okRoute("kunde.de")
	evil.ComposeDir = "/srv/<script>alert(1)</script>\n2 \"Fake\" - OK |x"
	evil.Tenant = "küche"
	d := buildCheckmk([]ledger.Payee{{ID: "a", Hostname: "<b>h</b>", LastReport: cmkNow}},
		map[string]Report{"a": cmkReport(evil)}, cmkNow, 2*time.Hour, 6*time.Hour)
	u := d.URLs[0]
	for _, s := range []string{u.ComposeDir, u.Unescaped.ComposeDir, d.Payees[0].Hostname} {
		if strings.ContainsAny(s, "\n\r|\"") {
			t.Errorf("nicht bereinigt: %q", s)
		}
	}
	if strings.Contains(u.ComposeDir, "<script>") || !strings.Contains(u.ComposeDir, "&lt;script&gt;") {
		t.Errorf("nicht escaped: %q", u.ComposeDir)
	}
	if !strings.Contains(u.Unescaped.ComposeDir, "<script>") {
		t.Errorf("Unescaped verändert: %q", u.Unescaped.ComposeDir)
	}
	if u.Tenant != "kueche" {
		t.Errorf("Umlaut: %q", u.Tenant)
	}
}

var cmkLine = regexp.MustCompile(`^[0-2] "[^"|]+" - (OK|WARN|CRIT) - [ -~]*$`)

// Die eingebaute Vorlage liefert gültige Local-Check-Zeilen mit Links.
func TestRenderCheckmk_Default(t *testing.T) {
	down := okRoute("olat.kunde.de")
	down.Down = true
	d := buildCheckmk([]ledger.Payee{{ID: "webproxy11", Hostname: "webproxy11.lan", LastReport: cmkNow.Add(-5 * time.Minute)}},
		map[string]Report{"webproxy11": cmkReport(okRoute("kunde.de"), down)}, cmkNow, 2*time.Hour, 6*time.Hour)
	out := renderCheckmk(t.TempDir(), d)
	lines := strings.Split(strings.TrimSuffix(out, "\n"), "\n")
	if len(lines) != 3 {
		t.Fatalf("%d Zeilen:\n%s", len(lines), out)
	}
	for _, l := range lines {
		if !cmkLine.MatchString(l) {
			t.Errorf("ungültige Zeile: %q", l)
		}
	}
	for _, want := range []string{
		`0 "Sultan Payee webproxy11" - OK - `,
		`0 "Sultan URL kunde.de" - OK - `,
		"https://kunde.de", "http://webdocker11.lan:8081", "/srv/kunde-a", "kunde", "webdocker11",
		`1 "Sultan URL olat.kunde.de" - WARN - gestoppt`,
	} {
		if !strings.Contains(out, want) {
			t.Errorf("fehlt %q in:\n%s", want, out)
		}
	}
}

// Eigene Vorlage in <data-dir>/checkmk hat Vorrang und wirkt sofort; eine
// defekte fällt auf die eingebaute zurück und meldet sich als CRIT.
func TestRenderCheckmk_CustomTemplate(t *testing.T) {
	dir := t.TempDir()
	d := buildCheckmk([]ledger.Payee{{ID: "p", LastReport: cmkNow}}, map[string]Report{"p": cmkReport(okRoute("kunde.de"))},
		cmkNow, 2*time.Hour, 6*time.Hour)
	os.MkdirAll(filepath.Join(dir, "checkmk"), 0o755)
	tmpl := filepath.Join(dir, "checkmk", CheckmkTemplateName)

	os.WriteFile(tmpl, []byte(`{{range .URLs}}{{.State}} "{{.Service}}" - {{status .State}} - eigen {{.Unescaped.Host}}{{"\n"}}{{end}}`), 0o644)
	if out := renderCheckmk(dir, d); out != "0 \"Sultan URL kunde.de\" - OK - eigen kunde.de\n" {
		t.Errorf("eigene Vorlage: %q", out)
	}

	os.WriteFile(tmpl, []byte(`{{range .URLs}`), 0o644)
	out := renderCheckmk(dir, d)
	if !strings.Contains(out, `2 "Sultan Accountant Vorlage" - CRIT - `) || !strings.Contains(out, `"Sultan URL kunde.de"`) {
		t.Errorf("defekte Vorlage: %q", out)
	}
	os.WriteFile(tmpl, []byte(`{{.GibtsNicht}}`), 0o644)
	if out := renderCheckmk(dir, d); !strings.Contains(out, `2 "Sultan Accountant Vorlage"`) {
		t.Errorf("Ausführungsfehler: %q", out)
	}
}

func TestDumpCheckmk(t *testing.T) {
	dir := t.TempDir()
	path, err := DumpCheckmk(dir, false)
	if err != nil || path != filepath.Join(dir, "checkmk", CheckmkTemplateName) {
		t.Fatalf("DumpCheckmk = %q, %v", path, err)
	}
	data, _ := os.ReadFile(path)
	if string(data) != defaultCheckmkTemplate {
		t.Error("Inhalt weicht von der eingebauten Vorlage ab")
	}
	if _, err := DumpCheckmk(dir, false); err == nil {
		t.Error("vorhandene Datei überschrieben")
	}
	if _, err := DumpCheckmk(dir, true); err != nil {
		t.Errorf("--force: %v", err)
	}
}

// Ende zu Ende: Bericht eines Payees erscheint auf dem Loopback-Port.
func TestCheckmkEndpoint(t *testing.T) {
	a, err := New(ctx, Config{DataDir: filepath.Join(t.TempDir(), "accdata"), Addr: "127.0.0.1:0", MetricsAddr: "127.0.0.1:0",
		Logger: slog.New(slog.DiscardHandler)})
	if err != nil {
		t.Fatal(err)
	}
	if err := a.Start(); err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { a.Shutdown(ctx) })
	key := enrolledPayee(t, a, "webproxy11")
	rep := cmkReport(okRoute("kunde.de"))
	rep.GeneratedAt = time.Now()
	body, _ := json.Marshal(rep)
	postReport(t, a, key, body)

	resp, err := http.Get("http://" + a.MetricsAddr() + "/metrics/checkmk")
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	out, _ := io.ReadAll(resp.Body)
	if resp.StatusCode != http.StatusOK || !strings.HasPrefix(resp.Header.Get("Content-Type"), "text/plain") ||
		!strings.Contains(string(out), `0 "Sultan URL kunde.de"`) || !strings.Contains(string(out), `0 "Sultan Payee webproxy11"`) {
		t.Errorf("Status %d, %q:\n%s", resp.StatusCode, resp.Header.Get("Content-Type"), out)
	}
}

func TestCheckmkEndpoint_Disabled(t *testing.T) {
	a, err := New(ctx, Config{DataDir: filepath.Join(t.TempDir(), "accdata"), Addr: "127.0.0.1:0", MetricsAddr: "none",
		Logger: slog.New(slog.DiscardHandler)})
	if err != nil {
		t.Fatal(err)
	}
	if err := a.Start(); err != nil {
		t.Fatal(err)
	}
	defer a.Shutdown(ctx)
	if a.MetricsAddr() != "" {
		t.Errorf("MetricsAddr = %q, erwartet leer", a.MetricsAddr())
	}
}