package mailx_test

import (
	"fmt"
	"strings"
	"testing"

	mailx "code.yun.ink/pkg/mailx"
)

// manyValidAddresses 生成 n 个合法地址
func manyValidAddresses(n int) []string {
	out := make([]string, n)
	for i := range out {
		out[i] = fmt.Sprintf("user%d@example.com", i)
	}
	return out
}

// manyHeaders 生成 n 个自定义头
func manyHeaders(n int) map[string]string {
	out := make(map[string]string, n)
	for i := 0; i < n; i++ {
		out[fmt.Sprintf("X-Test-%d", i)] = "v"
	}
	return out
}

func TestMessageBuilder(t *testing.T) {
	msg := mailx.NewMessage().
		From("sender@example.com").
		To("a@example.com", "b@example.com").
		Cc("cc@example.com").
		Bcc("bcc@example.com").
		Subject("subject").
		Body("body").
		ReplyTo("reply@example.com").
		Attach("dir/file.txt").
		AttachBytes("data.txt", []byte("hello")).
		Build()

	if msg.From != "sender@example.com" {
		t.Errorf("From = %q", msg.From)
	}
	if len(msg.To) != 2 || msg.To[0] != "a@example.com" || msg.To[1] != "b@example.com" {
		t.Errorf("To = %v", msg.To)
	}
	if len(msg.Cc) != 1 || msg.Cc[0] != "cc@example.com" {
		t.Errorf("Cc = %v", msg.Cc)
	}
	if len(msg.Bcc) != 1 || msg.Bcc[0] != "bcc@example.com" {
		t.Errorf("Bcc = %v", msg.Bcc)
	}
	if msg.Subject != "subject" || msg.Body != "body" || msg.ReplyTo != "reply@example.com" {
		t.Errorf("fields mismatch: %+v", msg)
	}
	if len(msg.Attachments) != 2 {
		t.Fatalf("Attachments len = %d, want 2", len(msg.Attachments))
	}
	if msg.Attachments[0].Name != "file.txt" || msg.Attachments[0].Path != "dir/file.txt" {
		t.Errorf("attachment[0] = %+v", msg.Attachments[0])
	}
	if msg.Attachments[1].Name != "data.txt" || string(msg.Attachments[1].Data) != "hello" {
		t.Errorf("attachment[1] = %+v", msg.Attachments[1])
	}
}

func TestMessageBuilderHTML(t *testing.T) {
	msg := mailx.NewMessage().HTML("<h1>hi</h1>").Build()
	if msg.Body != "<h1>hi</h1>" {
		t.Errorf("HTML() did not set Body, got %q", msg.Body)
	}
}

func TestMessageBuilderAppendTo(t *testing.T) {
	b := mailx.NewMessage().To("a@example.com")
	b.To("b@example.com") // 追加而非覆盖
	msg := b.Build()
	if len(msg.To) != 2 {
		t.Fatalf("To = %v, want 2 recipients", msg.To)
	}
}

func TestMessageValidate(t *testing.T) {
	cases := []struct {
		name    string
		msg     *mailx.Message
		wantErr string
	}{
		{"valid", &mailx.Message{To: []string{"a@b.com"}, Subject: "s"}, ""},
		{"no recipients", &mailx.Message{Subject: "s"}, "recipient"},
		{"no subject", &mailx.Message{To: []string{"a@b.com"}}, "subject"},
		{"empty", &mailx.Message{}, "recipient"},
		{"too many recipients", &mailx.Message{To: manyValidAddresses(mailx.MaxRecipients + 1), Subject: "s"}, "too many recipients"},
		{"invalid recipient", &mailx.Message{To: []string{"not-an-email"}, Subject: "s"}, "invalid recipient"},
		{"too many attachments", &mailx.Message{To: []string{"a@b.com"}, Subject: "s", Attachments: make([]mailx.Attachment, mailx.MaxAttachments+1)}, "too many attachments"},
		{"too many headers", &mailx.Message{To: []string{"a@b.com"}, Subject: "s", Headers: manyHeaders(mailx.MaxHeaderCount + 1)}, "too many custom headers"},
		{"message too large", &mailx.Message{To: []string{"a@b.com"}, Subject: "s", Body: strings.Repeat("x", mailx.MaxMessageSize+1)}, "message too large"},
		{"inline without cid", &mailx.Message{To: []string{"a@b.com"}, Subject: "s", Inline: []mailx.InlineImage{{Data: []byte{1}}}}, "requires a CID"},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			err := tc.msg.Validate()
			if tc.wantErr == "" {
				if err != nil {
					t.Fatalf("Validate() = %v, want nil", err)
				}
				return
			}
			if err == nil || !strings.Contains(err.Error(), tc.wantErr) {
				t.Fatalf("Validate() = %v, want containing %q", err, tc.wantErr)
			}
		})
	}
}