package handlers

import (
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"testing"

	"github.com/mixeme/selfpost/internal/store"
	"github.com/mixeme/selfpost/internal/web/auth"
)

// After log rotation renames mail.log away, Postfix takes about a second to
// recreate it on reload (spec B.2); a missing file in that window is a normal,
// transient gap, not an operator-facing failure.
func TestReadLogTailMissingFileIsNotAnError(t *testing.T) {
	h := &Handlers{cfg: Config{MailLogPath: filepath.Join(t.TempDir(), "mail.log")}}

	lines, errText := h.readLogTail()
	if lines != nil {
		t.Errorf("lines = %v, want nil", lines)
	}
	if errText != "" {
		t.Errorf("errText = %q, want empty (missing file is not an error)", errText)
	}
}

// The delivery log is a list of messages, not a dump of the journal: it shows
// when, from, to, subject and status, and links each row to the page carrying
// the rest. A column added back here is one the table has no width for.
func TestDeliveryLogShowsOnlyTheIdentifyingColumns(t *testing.T) {
	h, row := serverWithDelivery(t)

	out := getBody(t, h.HandleDeliveries, "/deliveries")
	for _, want := range []string{
		row.CreatedAt.Format("2006-01-02 15:04:05"),
		"noreply@bs.example.ru", "public@example.ru",
		"Проверка", ">sent<", `href="/deliveries/` + itoa(row.ID),
	} {
		if !strings.Contains(out, want) {
			t.Errorf("delivery log is missing %q:\n%s", want, out)
		}
	}
	// Domain and application stay available as filters; what the table must not
	// carry is a column of them per row.
	for _, unwanted := range []string{"<th>Domain</th>", "<th>App</th>", "Queuer3C"} {
		if strings.Contains(out, unwanted) {
			t.Errorf("delivery log still shows %q; that detail belongs on the delivery page", unwanted)
		}
	}
}

// Subjects reached the journal as RFC 2047 encoded-words before the milter
// decoded them, and those rows are still in the send log. Decoding on the way
// out is what keeps them readable, so the encoding must not survive to the page.
func TestDeliveryLogDecodesStoredEncodedSubjects(t *testing.T) {
	h, _ := serverWithDelivery(t)

	for name, out := range map[string]string{
		"log":  getBody(t, h.HandleDeliveries, "/deliveries"),
		"rows": getBody(t, h.HandleDeliveriesRows, "/deliveries/rows"),
	} {
		if strings.Contains(out, "=?utf-8?Q?") {
			t.Errorf("%s shows the subject's MIME encoding instead of its text:\n%s", name, out)
		}
		if !strings.Contains(out, "Проверка") {
			t.Errorf("%s does not show the decoded subject:\n%s", name, out)
		}
	}
}

// Everything the log dropped has to be somewhere, and that somewhere is the
// per-row page — including for a row still holding an encoded subject.
func TestDeliveryPageShowsWhatTheLogOmits(t *testing.T) {
	h, row := serverWithDelivery(t)

	out := getBody(t, h.HandleDelivery, "/deliveries/"+itoa(row.ID)+"?domain=bs.example.ru&p=2")
	for _, want := range []string{
		"bs.example.ru", "Queuer3C", "4A1B2C3D", "Проверка",
		"noreply@bs.example.ru", "public@example.ru", "sent",
		`href="/deliveries?domain=bs.example.ru&amp;p=2"`,
	} {
		if !strings.Contains(out, want) {
			t.Errorf("delivery page is missing %q:\n%s", want, out)
		}
	}
	if strings.Contains(out, "=?utf-8?Q?") {
		t.Errorf("delivery page shows the subject's MIME encoding instead of its text:\n%s", out)
	}
}

// The page's second column is the message's history: the two timestamps the
// journal holds, stated as the steps they stand for, so a row is readable as
// what happened to the message rather than as a list of fields.
func TestDeliveryPageTellsTheMessagesHistory(t *testing.T) {
	h, row := serverWithDelivery(t)

	out := getBody(t, h.HandleDelivery, "/deliveries/"+itoa(row.ID))
	for _, want := range []string{
		"Accepted and queued", "Delivered",
		row.CreatedAt.Format("2006-01-02 15:04:05"),
		row.UpdatedAt.Format("2006-01-02 15:04:05"),
		// A delivered message is "ok" in the panel's own badge vocabulary, the
		// same one the status page and the DNS checks use.
		`class="st st-ok"`,
	} {
		if !strings.Contains(out, want) {
			t.Errorf("delivery page is missing %q:\n%s", want, out)
		}
	}
	// Accepted comes before delivered: a history read in the wrong order is
	// worse than none.
	if strings.Index(out, "Accepted and queued") > strings.Index(out, "Delivered") {
		t.Errorf("the history is not in the order it happened:\n%s", out)
	}
}

// A queued message has no second timestamp to state, so the step it is waiting
// for is drawn as one that has not happened rather than dated with the moment
// the row was written.
func TestDeliveryPageMarksAQueuedMessageAsStillWaiting(t *testing.T) {
	h, _ := serverWithDelivery(t)
	if err := h.store.InsertQueued(store.SendLogEntry{
		QueueID: "7F7F7F7F", Domain: "bs.example.ru", AppLogin: "Queuer3C",
		From: "noreply@bs.example.ru", To: "waiting@example.ru", Subject: "Still going",
	}); err != nil {
		t.Fatalf("insert: %v", err)
	}
	rows, err := h.store.QuerySendLog(store.SendLogFilter{}, 1, 0)
	if err != nil || len(rows) != 1 {
		t.Fatalf("query: %v (%d rows)", err, len(rows))
	}

	out := getBody(t, h.HandleDelivery, "/deliveries/"+itoa(rows[0].ID))
	for _, want := range []string{"Waiting for a delivery report", "pending", "not yet"} {
		if !strings.Contains(out, want) {
			t.Errorf("delivery page does not mark the message as still waiting (%q):\n%s", want, out)
		}
	}
}

// The queue id used to be printed as something to go and search the system log
// for by hand; the page does that search now, and shows only this message's
// lines — as a table of when and what, so the seconds between the connection
// and the reply line up down one edge.
func TestDeliveryPageShowsThisMessagesLogLines(t *testing.T) {
	h, row := serverWithDelivery(t)
	h.cfg.MailLogPath = writeMailLog(t,
		"2026-08-03T05:15:52.219218+00:00 host postfix/smtpd[20]: 4A1B2C3D: client=mail.example.com[203.0.113.4]",
		"2026-08-03T05:15:52.300000+00:00 host postfix/qmgr[10]: 99999999: from=<other@example.ru>, size=500, nrcpt=1 (queue active)",
		"2026-08-03T05:16:03.884210+00:00 host postfix/smtp[26]: 4A1B2C3D: to=<public@example.ru>, dsn=2.0.0, status=sent (250 OK)",
	)

	out := getBody(t, h.HandleDelivery, "/deliveries/"+itoa(row.ID))
	for _, want := range []string{
		"<th>Time</th>", "<th>Message</th>",
		// The stamp is split off into its own cell, without the microseconds
		// and the offset that make it the widest thing on the line.
		`<td class="time muted">2026-08-03 05:15:52</td>`,
		`<td class="time muted">2026-08-03 05:16:03</td>`,
		"client=mail.example.com", "status=sent (250 OK)",
	} {
		if !strings.Contains(out, want) {
			t.Errorf("delivery log table is missing %q:\n%s", want, out)
		}
	}
	if strings.Contains(out, "99999999") {
		t.Errorf("delivery page shows another message's log line:\n%s", out)
	}
}

// A line whose head is not a timestamp still has to show in full; the format is
// the log's, not ours, and a line we cannot split is a line we must not drop.
func TestDeliveryPageKeepsAnUnstampedLogLineWhole(t *testing.T) {
	h, row := serverWithDelivery(t)
	h.cfg.MailLogPath = writeMailLog(t, "host postfix/smtp[26]: 4A1B2C3D: to=<public@example.ru>, status=sent (250 OK)")

	out := getBody(t, h.HandleDelivery, "/deliveries/"+itoa(row.ID))
	if !strings.Contains(out, "host postfix/smtp[26]: 4A1B2C3D: to=&lt;public@example.ru&gt;, status=sent (250 OK)") {
		t.Errorf("an unstamped log line did not survive the split into columns:\n%s", out)
	}
}

// Rows outlive mail.log, and a message the milter refused never reached the
// queue at all. Neither is a fault, so neither may render as an error.
func TestDeliveryPageExplainsAnEmptyDeliveryLog(t *testing.T) {
	h, row := serverWithDelivery(t)
	h.cfg.MailLogPath = filepath.Join(t.TempDir(), "mail.log") // never created

	out := getBody(t, h.HandleDelivery, "/deliveries/"+itoa(row.ID))
	if !strings.Contains(out, "rotated away") {
		t.Errorf("delivery page does not explain the empty delivery log:\n%s", out)
	}
	if strings.Contains(out, `class="error"`) || strings.Contains(out, "Could not read the mail log") {
		t.Errorf("an aged-out delivery log is reported as a failure:\n%s", out)
	}
}

// Send-log rows are pruned on the retention window, so a bookmarked delivery
// that no longer exists is a 404, not a 500.
func TestDeliveryPageNotFound(t *testing.T) {
	h, _ := serverWithDelivery(t)

	for _, path := range []string{"/deliveries/999999", "/deliveries/abc", "/deliveries/0"} {
		rec := httptest.NewRecorder()
		req := httptest.NewRequest(http.MethodGet, path, nil)
		req.SetPathValue("id", strings.TrimPrefix(path, "/deliveries/"))
		h.HandleDelivery(rec, req)
		if rec.Code != http.StatusNotFound {
			t.Errorf("GET %s = %d, want 404", path, rec.Code)
		}
	}
}

// serverWithDelivery builds a panel over a store holding one delivery, written
// the way the journal-milter wrote them before it decoded subjects itself.
func serverWithDelivery(t *testing.T) (*Handlers, store.SendLogRow) {
	t.Helper()
	st, err := store.Open(filepath.Join(t.TempDir(), "test.db"))
	if err != nil {
		t.Fatalf("open store: %v", err)
	}
	t.Cleanup(func() { _ = st.Close() })

	if err := st.InsertQueued(store.SendLogEntry{
		QueueID:  "4A1B2C3D",
		Domain:   "bs.example.ru",
		AppLogin: "Queuer3C",
		From:     "noreply@bs.example.ru",
		To:       "public@example.ru",
		Subject:  "=?utf-8?Q?=D0=9F=D1=80=D0=BE=D0=B2=D0=B5=D1=80=D0=BA=D0=B0?=",
	}); err != nil {
		t.Fatalf("insert: %v", err)
	}
	if _, err := st.UpdateStatus("4A1B2C3D", "public@example.ru", store.StatusSent); err != nil {
		t.Fatalf("update status: %v", err)
	}
	rows, err := st.QuerySendLog(store.SendLogFilter{}, 1, 0)
	if err != nil || len(rows) != 1 {
		t.Fatalf("query: %v (%d rows)", err, len(rows))
	}

	return &Handlers{store: st, view: mustView(t), cfg: Config{Version: "test"}}, rows[0]
}

// getBody runs one handler over a GET and returns the page it wrote, failing
// the test on any non-200. The path's {id} is bound by hand because these calls
// bypass the router that would otherwise fill it in.
func getBody(t *testing.T, h http.HandlerFunc, target string) string {
	t.Helper()
	rec := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, target, nil)
	req = auth.RequestWithPrincipal(req, auth.Principal{
		ID:       1,
		Username: "admin",
		Role:     auth.RoleGlobal,
	})
	if rest, ok := strings.CutPrefix(req.URL.Path, "/deliveries/"); ok && rest != "rows" {
		req.SetPathValue("id", rest)
	}
	h(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("GET %s = %d, want 200:\n%s", target, rec.Code, rec.Body.String())
	}
	return rec.Body.String()
}

func itoa(n int64) string { return strconv.FormatInt(n, 10) }

// writeMailLog creates a mail.log holding the given lines and returns its path,
// for the pages that read the log rather than the journal.
func writeMailLog(t *testing.T, lines ...string) string {
	t.Helper()
	path := filepath.Join(t.TempDir(), "mail.log")
	if err := os.WriteFile(path, []byte(strings.Join(lines, "\n")+"\n"), 0o644); err != nil {
		t.Fatalf("write mail.log: %v", err)
	}
	return path
}