package cli

import (
	"path/filepath"
	"testing"
	"time"

	"git.dcglab.co.uk/steve/emcli/internal/mail"
	"git.dcglab.co.uk/steve/emcli/internal/store"
)

// sendDeps builds Deps wired to a recording fake sender and an optional fake
// mailer (for reply-to). The named account is created per the supplied template.
func sendDeps(t *testing.T, acc store.Account, fm *fakeMailer) (Deps, *[]mail.OutgoingMessage, *[]byte) {
	t.Helper()
	st, err := store.Open(filepath.Join(t.TempDir(), "e.db"))
	if err != nil {
		t.Fatalf("store: %v", err)
	}
	if err := st.InitKeys(testKey(), testKey()); err != nil {
		t.Fatalf("InitKeys: %v", err)
	}
	t.Cleanup(func() { st.Close() })
	if _, err := st.AddAccount(acc); err != nil {
		t.Fatalf("AddAccount: %v", err)
	}
	var sent []mail.OutgoingMessage
	buf := &[]byte{}
	d := Deps{
		Store: st,
		Dial:  func(store.Account) (Mailer, error) { return fm, nil },
		Now:   func() time.Time { return time.Date(2026, 6, 22, 0, 0, 0, 0, time.UTC) },
		Out:   bufWriter{buf},
		Send: func(_ store.Account, m mail.OutgoingMessage) error {
			sent = append(sent, m)
			return nil
		},
	}
	return d, &sent, buf
}

type bufWriter struct{ b *[]byte }

func (w bufWriter) Write(p []byte) (int, error) { *w.b = append(*w.b, p...); return len(p), nil }

func rwAccount() store.Account {
	return store.Account{
		Name: "send", Mode: "RW", IMAPHost: "h", IMAPPort: 993, IMAPSecurity: "tls",
		SMTPHost: "h", SMTPPort: 465, SMTPSecurity: "tls",
		AuthType: "password", Username: "emcli@stevecliff.com", Password: "pw",
	}
}

func TestSendHappyPath(t *testing.T) {
	d, sent, buf := sendDeps(t, rwAccount(), nil)
	err := SendCmd(d, "send", []string{"me@stevecliff.com"}, nil, nil, "hi", "body", nil, 0, "INBOX")
	if err != nil {
		t.Fatalf("SendCmd: %v", err)
	}
	res := decode(t, *buf)
	if res["error"] != false {
		t.Fatalf("unexpected error: %v", res)
	}
	if len(*sent) != 1 {
		t.Fatalf("want 1 send, got %d", len(*sent))
	}
	m := (*sent)[0]
	if len(m.To) != 1 || m.To[0] != "me@stevecliff.com" || m.Subject != "hi" {
		t.Fatalf("wrong outgoing message: %+v", m)
	}
}

func TestSendROBlocked(t *testing.T) {
	acc := rwAccount()
	acc.Mode = "RO"
	d, sent, buf := sendDeps(t, acc, nil)
	_ = SendCmd(d, "send", []string{"me@stevecliff.com"}, nil, nil, "hi", "body", nil, 0, "INBOX")
	res := decode(t, *buf)
	if res["error"] != true {
		t.Fatal("RO send must be blocked")
	}
	if len(*sent) != 0 {
		t.Fatal("sender must not be called when blocked")
	}
}

func TestSendWhitelistOutBlocked(t *testing.T) {
	acc := rwAccount()
	acc.WhitelistOutEnabled = true
	d, sent, buf := sendDeps(t, acc, nil)
	_ = d.Store.AddWhitelist("send", store.DirOut, "@stevecliff.com")
	// recipient not on the whitelist -> blocked
	_ = SendCmd(d, "send", []string{"stranger@elsewhere.com"}, nil, nil, "hi", "body", nil, 0, "INBOX")
	res := decode(t, *buf)
	if res["error"] != true {
		t.Fatal("non-whitelisted recipient must be blocked")
	}
	if len(*sent) != 0 {
		t.Fatal("sender must not be called when blocked")
	}
}

func TestSendWhitelistOutAllowed(t *testing.T) {
	acc := rwAccount()
	acc.WhitelistOutEnabled = true
	d, sent, _ := sendDeps(t, acc, nil)
	_ = d.Store.AddWhitelist("send", store.DirOut, "@stevecliff.com")
	if err := SendCmd(d, "send", []string{"me@stevecliff.com"}, nil, nil, "hi", "body", nil, 0, "INBOX"); err != nil {
		t.Fatalf("SendCmd: %v", err)
	}
	if len(*sent) != 1 {
		t.Fatalf("whitelisted recipient should be sent, got %d", len(*sent))
	}
}

func TestSendReplyToThreadsHeaders(t *testing.T) {
	acc := rwAccount()
	fm := &fakeMailer{
		uidValidity: 1, maxUID: 100,
		headers: []mail.Header{
			{UID: 42, From: "me@stevecliff.com", Subject: "orig",
				MessageID: "orig@stevecliff.com", References: []string{"root@stevecliff.com"}},
		},
	}
	d, sent, _ := sendDeps(t, acc, fm)
	if err := SendCmd(d, "send", []string{"me@stevecliff.com"}, nil, nil, "re: orig", "body", nil, 42, "INBOX"); err != nil {
		t.Fatalf("SendCmd: %v", err)
	}
	if len(*sent) != 1 {
		t.Fatalf("want 1 send, got %d", len(*sent))
	}
	m := (*sent)[0]
	if m.InReplyTo != "orig@stevecliff.com" {
		t.Fatalf("InReplyTo=%q", m.InReplyTo)
	}
	// References should chain the source's references then the source itself.
	if len(m.References) != 2 || m.References[0] != "root@stevecliff.com" || m.References[1] != "orig@stevecliff.com" {
		t.Fatalf("References=%v", m.References)
	}
}

func TestSendUsesConfiguredFromAddress(t *testing.T) {
	acc := rwAccount()
	acc.FromAddress = "Steve Cliff <me@stevecliff.com>"
	d, sent, _ := sendDeps(t, acc, nil)
	if err := SendCmd(d, "send", []string{"me@stevecliff.com"}, nil, nil, "hi", "body", nil, 0, "INBOX"); err != nil {
		t.Fatalf("SendCmd: %v", err)
	}
	if len(*sent) != 1 {
		t.Fatalf("want 1 send, got %d", len(*sent))
	}
	if got := (*sent)[0].From; got != "Steve Cliff <me@stevecliff.com>" {
		t.Fatalf("From = %q, want configured from-address", got)
	}
}

func TestSendFallsBackToUsernameAsFrom(t *testing.T) {
	// rwAccount has no FromAddress, so From must be the login username.
	d, sent, _ := sendDeps(t, rwAccount(), nil)
	if err := SendCmd(d, "send", []string{"me@stevecliff.com"}, nil, nil, "hi", "body", nil, 0, "INBOX"); err != nil {
		t.Fatalf("SendCmd: %v", err)
	}
	if got := (*sent)[0].From; got != "emcli@stevecliff.com" {
		t.Fatalf("From = %q, want username fallback", got)
	}
}

func TestSendReplyToFilteredSourceNotFound(t *testing.T) {
	acc := rwAccount()
	acc.WhitelistInEnabled = true // inbound filter active
	fm := &fakeMailer{
		uidValidity: 1, maxUID: 100,
		headers: []mail.Header{
			{UID: 42, From: "eve@evil.com", Subject: "spam", MessageID: "spam@evil.com"},
		},
	}
	d, sent, buf := sendDeps(t, acc, fm)
	_ = d.Store.AddWhitelist("send", store.DirIn, "@stevecliff.com") // 42 is from evil.com => filtered
	_ = SendCmd(d, "send", []string{"me@stevecliff.com"}, nil, nil, "re", "body", nil, 42, "INBOX")
	res := decode(t, *buf)
	if res["error"] != true {
		t.Fatal("reply to a filtered source must fail")
	}
	ed := res["error_detail"].(map[string]any)
	if ed["code"] != "not_found" {
		t.Fatalf("want not_found, got %v", ed["code"])
	}
	if len(*sent) != 0 {
		t.Fatal("must not send when reply source is filtered")
	}
}