package infra

import (
	"testing"
)

func TestEmailBuildHTML(t *testing.T) {
	t.Run("construye mensaje html con campos basicos", func(t *testing.T) {
		msg := EmailBuildHTML("alice@example.com", []string{"bob@example.com"}, "Hola", "<b>Hola</b>")
		if msg.From != "alice@example.com" {
			t.Errorf("From: got %q, want %q", msg.From, "alice@example.com")
		}
		if len(msg.To) != 1 || msg.To[0] != "bob@example.com" {
			t.Errorf("To: got %v, want [bob@example.com]", msg.To)
		}
		if msg.Subject != "Hola" {
			t.Errorf("Subject: got %q, want %q", msg.Subject, "Hola")
		}
		if msg.BodyHTML != "<b>Hola</b>" {
			t.Errorf("BodyHTML: got %q, want %q", msg.BodyHTML, "<b>Hola</b>")
		}
	})

	t.Run("copia el slice to para evitar aliasing", func(t *testing.T) {
		to := []string{"a@example.com", "b@example.com"}
		msg := EmailBuildHTML("x@x.com", to, "s", "h")
		to[0] = "mutated@example.com"
		if msg.To[0] == "mutated@example.com" {
			t.Error("To slice was aliased — mutation affected the message")
		}
	})

	t.Run("campos no usados quedan vacios", func(t *testing.T) {
		msg := EmailBuildHTML("f@example.com", []string{"t@example.com"}, "s", "h")
		if msg.BodyText != "" {
			t.Errorf("BodyText should be empty, got %q", msg.BodyText)
		}
		if len(msg.CC) != 0 {
			t.Errorf("CC should be empty, got %v", msg.CC)
		}
		if len(msg.BCC) != 0 {
			t.Errorf("BCC should be empty, got %v", msg.BCC)
		}
		if len(msg.Attachments) != 0 {
			t.Errorf("Attachments should be empty, got %v", msg.Attachments)
		}
	})
}

func TestEmailBuildText(t *testing.T) {
	t.Run("construye mensaje text con campos basicos", func(t *testing.T) {
		msg := EmailBuildText("alice@example.com", []string{"bob@example.com"}, "Alerta", "Servidor caido")
		if msg.BodyText != "Servidor caido" {
			t.Errorf("BodyText: got %q, want %q", msg.BodyText, "Servidor caido")
		}
		if msg.From != "alice@example.com" {
			t.Errorf("From: got %q, want %q", msg.From, "alice@example.com")
		}
		if msg.Subject != "Alerta" {
			t.Errorf("Subject: got %q, want %q", msg.Subject, "Alerta")
		}
	})

	t.Run("body html queda vacio", func(t *testing.T) {
		msg := EmailBuildText("f@x.com", []string{"t@x.com"}, "s", "body")
		if msg.BodyHTML != "" {
			t.Errorf("BodyHTML should be empty, got %q", msg.BodyHTML)
		}
	})
}

func TestEmailWithAttachment(t *testing.T) {
	t.Run("agrega adjunto sin mutar el original", func(t *testing.T) {
		orig := EmailBuildHTML("a@example.com", []string{"b@example.com"}, "s", "h")
		att := EmailAttachment{Filename: "f.pdf", ContentType: "application/pdf", Data: []byte("data")}
		msg2 := EmailWithAttachment(orig, att)

		if len(orig.Attachments) != 0 {
			t.Errorf("original was mutated: got %d attachments, want 0", len(orig.Attachments))
		}
		if len(msg2.Attachments) != 1 {
			t.Errorf("got %d attachments, want 1", len(msg2.Attachments))
		}
		if msg2.Attachments[0].Filename != "f.pdf" {
			t.Errorf("Filename: got %q, want %q", msg2.Attachments[0].Filename, "f.pdf")
		}
	})

	t.Run("multiples adjuntos se acumulan", func(t *testing.T) {
		msg := EmailBuildHTML("a@x.com", []string{"b@x.com"}, "s", "h")
		msg = EmailWithAttachment(msg, EmailAttachment{Filename: "a1.txt", ContentType: "text/plain", Data: []byte("1")})
		msg = EmailWithAttachment(msg, EmailAttachment{Filename: "a2.txt", ContentType: "text/plain", Data: []byte("2")})
		if len(msg.Attachments) != 2 {
			t.Errorf("got %d attachments, want 2", len(msg.Attachments))
		}
	})

	t.Run("copia todos los campos del mensaje", func(t *testing.T) {
		orig := EmailMessage{
			From:     "a@x.com",
			To:       []string{"b@x.com"},
			CC:       []string{"c@x.com"},
			BCC:      []string{"d@x.com"},
			Subject:  "Test",
			BodyHTML: "<p>Hi</p>",
			BodyText: "Hi",
			Headers:  map[string]string{"X-Test": "value"},
		}
		att := EmailAttachment{Filename: "f.png", ContentType: "image/png", Data: []byte("img")}
		msg2 := EmailWithAttachment(orig, att)

		if msg2.From != orig.From {
			t.Errorf("From mismatch: %q vs %q", msg2.From, orig.From)
		}
		if msg2.Subject != orig.Subject {
			t.Errorf("Subject mismatch: %q vs %q", msg2.Subject, orig.Subject)
		}
		if len(msg2.CC) != 1 || msg2.CC[0] != "c@x.com" {
			t.Errorf("CC not copied: %v", msg2.CC)
		}
		if msg2.Headers["X-Test"] != "value" {
			t.Errorf("Headers not copied: %v", msg2.Headers)
		}
	})
}
