package email

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	channelpkg "github.com/gochat/gochat/internal/channel"
	"github.com/gochat/gochat/internal/model"
)

func TestNewWebhookHandler_Cov4(t *testing.T) {
	h := NewWebhookHandler()
	assert.NotNil(t, h)
}

func TestWebhookHandler_HandleWebhookRequest_EmptyBody_Cov4(t *testing.T) {
	h := NewWebhookHandler()
	w := httptest.NewRecorder()
	r := httptest.NewRequest("POST", "/webhook", nil)
	h.HandleWebhookRequest(w, r)
	assert.Equal(t, http.StatusBadRequest, w.Code)
}

func TestWebhookHandler_HandleWebhookRequest_ReadError_Cov4(t *testing.T) {
	h := NewWebhookHandler()
	w := httptest.NewRecorder()
	r := httptest.NewRequest("POST", "/webhook", &errReaderCov4{})
	h.HandleWebhookRequest(w, r)
	assert.Equal(t, http.StatusInternalServerError, w.Code)
}

func TestWebhookHandler_HandleWebhookRequest_ValidMailgun_Cov4(t *testing.T) {
	h := NewWebhookHandler()
	w := httptest.NewRecorder()
	body := `{"from":"sender@example.com","subject":"Test","body-plain":"Hello","to":"recipient@example.com","Message-Id":"msg-1"}`
	r := httptest.NewRequest("POST", "/webhook", strings.NewReader(body))
	r.Header.Set("X-Mailgun-Sid", "12345")
	r.Header.Set("Content-Type", "application/json")
	h.HandleWebhookRequest(w, r)
	assert.Equal(t, http.StatusOK, w.Code)
	assert.Contains(t, w.Body.String(), "accepted")
}

func TestWebhookHandler_HandleWebhookRequest_ValidSendGrid_Cov4(t *testing.T) {
	h := NewWebhookHandler()
	w := httptest.NewRecorder()
	body := `{"envelope":{"from":"sender@example.com","to":["recipient@example.com"]},"subject":"Test","text":"Hello","html":"<p>Hello</p>","messageId":"msg-2"}`
	r := httptest.NewRequest("POST", "/webhook", strings.NewReader(body))
	r.Header.Set("X-Sg-Envelope-Id", "env-123")
	r.Header.Set("Content-Type", "application/json")
	h.HandleWebhookRequest(w, r)
	assert.Equal(t, http.StatusOK, w.Code)
}

func TestWebhookHandler_HandleWebhookRequest_GenericJSON_Cov4(t *testing.T) {
	h := NewWebhookHandler()
	w := httptest.NewRecorder()
	body := `{"from":"sender@example.com","subject":"Test","text":"Hello","to":"recipient@example.com","message_id":"msg-3"}`
	r := httptest.NewRequest("POST", "/webhook", strings.NewReader(body))
	r.Header.Set("Content-Type", "application/json")
	h.HandleWebhookRequest(w, r)
	assert.Equal(t, http.StatusOK, w.Code)
}

func TestWebhookHandler_HandleWebhookRequest_RawEmail_Cov4(t *testing.T) {
	h := NewWebhookHandler()
	w := httptest.NewRecorder()
	body := "From: sender@example.com\r\nSubject: Test\r\n\r\nHello world"
	r := httptest.NewRequest("POST", "/webhook", strings.NewReader(body))
	h.HandleWebhookRequest(w, r)
	assert.Equal(t, http.StatusOK, w.Code)
}

func TestWebhookHandler_HandleWebhookRequest_InvalidMailgun_Cov4(t *testing.T) {
	h := NewWebhookHandler()
	w := httptest.NewRecorder()
	body := "invalid json"
	r := httptest.NewRequest("POST", "/webhook", strings.NewReader(body))
	r.Header.Set("X-Mailgun-Sid", "12345")
	h.HandleWebhookRequest(w, r)
	// Should still return 200 to prevent retries
	assert.Equal(t, http.StatusOK, w.Code)
}

func TestWebhookHandler_ParseWebhookBody_Cov4(t *testing.T) {
	h := NewWebhookHandler()

	t.Run("mailgun", func(t *testing.T) {
		body := `{"from":"sender@example.com","subject":"Test","body-plain":"Hello","to":"recipient@example.com","Message-Id":"msg-1"}`
		headers := http.Header{}
		headers.Set("X-Mailgun-Sid", "12345")
		msg, err := h.ParseWebhookBody([]byte(body), headers)
		require.NoError(t, err)
		assert.Equal(t, "sender@example.com", msg.FromAddress)
		assert.Equal(t, "Test", msg.Subject)
	})

	t.Run("sendgrid", func(t *testing.T) {
		body := `{"envelope":{"from":"sender@example.com","to":["recipient@example.com"]},"subject":"Test","text":"Hello"}`
		headers := http.Header{}
		headers.Set("X-Sg-Envelope-Id", "env-123")
		msg, err := h.ParseWebhookBody([]byte(body), headers)
		require.NoError(t, err)
		assert.Equal(t, "sender@example.com", msg.FromAddress)
		assert.Equal(t, "Test", msg.Subject)
	})

	t.Run("generic json", func(t *testing.T) {
		body := `{"from":"sender@example.com","subject":"Test","text":"Hello","to":"recipient@example.com"}`
		headers := http.Header{}
		headers.Set("Content-Type", "application/json")
		msg, err := h.ParseWebhookBody([]byte(body), headers)
		require.NoError(t, err)
		assert.Equal(t, "sender@example.com", msg.FromAddress)
	})

	t.Run("raw email", func(t *testing.T) {
		body := "From: sender@example.com\r\nSubject: Test\r\n\r\nHello"
		msg, err := h.ParseWebhookBody([]byte(body), http.Header{})
		require.NoError(t, err)
		assert.NotEmpty(t, msg.TextContent)
	})
}

func TestIsMailgunPayload_Cov4(t *testing.T) {
	headers := http.Header{}
	assert.False(t, isMailgunPayload(headers))
	headers.Set("X-Mailgun-Sid", "12345")
	assert.True(t, isMailgunPayload(headers))
}

func TestIsSendGridPayload_Cov4(t *testing.T) {
	headers := http.Header{}
	assert.False(t, isSendGridPayload(headers))
	headers.Set("X-Sg-Envelope-Id", "env-123")
	assert.True(t, isSendGridPayload(headers))
}

func TestParseMailgunPayload_Cov4(t *testing.T) {
	t.Run("valid", func(t *testing.T) {
		body := `{"from":"sender@example.com","subject":"Test","body-plain":"Hello","to":"recipient@example.com","Message-Id":"msg-1","In-Reply-To":"parent","References":"<parent>","Date":"2024-01-01","body-html":"<p>Hello</p>"}`
		msg, err := parseMailgunPayload([]byte(body))
		require.NoError(t, err)
		assert.Equal(t, "sender@example.com", msg.FromAddress)
		assert.Equal(t, "Test", msg.Subject)
		assert.Equal(t, "Hello", msg.TextContent)
		assert.Equal(t, "<p>Hello</p>", msg.HTMLContent)
		assert.Equal(t, "msg-1", msg.MessageID)
	})

	t.Run("invalid json", func(t *testing.T) {
		_, err := parseMailgunPayload([]byte("invalid"))
		assert.Error(t, err)
	})
}

func TestParseSendGridPayload_Cov4(t *testing.T) {
	t.Run("valid", func(t *testing.T) {
		body := `{"envelope":{"from":"sender@example.com","to":["recipient@example.com"]},"subject":"Test","text":"Hello","html":"<p>Hello</p>","messageId":"msg-2","in_reply_to":"parent","date":"2024-01-01"}`
		msg, err := parseSendGridPayload([]byte(body))
		require.NoError(t, err)
		assert.Equal(t, "sender@example.com", msg.FromAddress)
		assert.Equal(t, "Test", msg.Subject)
		assert.Equal(t, "Hello", msg.TextContent)
		assert.Equal(t, "<p>Hello</p>", msg.HTMLContent)
		assert.Equal(t, "msg-2", msg.MessageID)
		assert.Equal(t, "parent", msg.InReplyTo)
	})

	t.Run("invalid json", func(t *testing.T) {
		_, err := parseSendGridPayload([]byte("invalid"))
		assert.Error(t, err)
	})
}

func TestParseGenericJSONPayload_Cov4(t *testing.T) {
	t.Run("valid", func(t *testing.T) {
		data := map[string]interface{}{
			"from":        "sender@example.com",
			"subject":     "Test",
			"text":        "Hello",
			"html":        "<p>Hello</p>",
			"message_id":  "msg-3",
			"in_reply_to": "parent",
			"date":        "2024-01-01",
			"to":          "recipient@example.com",
		}
		msg, err := parseGenericJSONPayload(data)
		require.NoError(t, err)
		assert.Equal(t, "sender@example.com", msg.FromAddress)
		assert.Equal(t, "Test", msg.Subject)
		assert.Equal(t, "Hello", msg.TextContent)
		assert.Equal(t, "<p>Hello</p>", msg.HTMLContent)
		assert.Equal(t, "msg-3", msg.MessageID)
		assert.Equal(t, "parent", msg.InReplyTo)
		assert.Equal(t, []string{"recipient@example.com"}, msg.ToAddresses)
	})
}

func TestParseRawEmail_Cov4(t *testing.T) {
	body := "From: sender@example.com\r\nSubject: Test\r\n\r\nHello world"
	msg, err := parseRawEmail([]byte(body))
	require.NoError(t, err)
	assert.NotEmpty(t, msg.TextContent)
	assert.Contains(t, msg.TextContent, "Hello world")
}

func TestEmailProvider_SendMessage_WithSMTPConfig_Cov4(t *testing.T) {
	provider := NewEmailProvider(NewService(), &Repository{}, NewIncomingProcessor(nil))
	ctx := context.Background()
	inbox := &model.Inbox{
		Base:          model.Base{ID: 1},
		AccountID:     1,
		ChannelConfig: `{"smtp_email":"support@example.com","smtp_address":"smtp.example.com","smtp_port":587,"smtp_password":"pass","imap_address":"imap.example.com","imap_port":993,"imap_email":"support@example.com","imap_password":"pass"}`,
	}
	contact := &model.Contact{SourceID: "recipient@example.com"}
	msg := &model.Message{Content: "test"}

	// This will try to connect to smtp.example.com — should fail with network error
	_, err := provider.SendMessage(ctx, inbox, msg, contact)
	assert.Error(t, err)
}

func TestEmailProvider_PollInterval_Cov4(t *testing.T) {
	provider := NewEmailProvider(NewService(), &Repository{}, NewIncomingProcessor(nil))
	interval := provider.PollInterval()
	assert.NotZero(t, interval)
}

func TestEmailProvider_PollMessages_Cov4(t *testing.T) {
	provider := NewEmailProvider(NewService(), &Repository{}, NewIncomingProcessor(nil))
	inbox := &model.Inbox{Base: model.Base{ID: 1}, AccountID: 1}
	// With empty config, should fail
	_, err := provider.PollMessages(context.Background(), inbox)
	assert.Error(t, err)
}

func TestEmailMessage_JSON_Cov4(t *testing.T) {
	msg := EmailMessage{
		MessageID:   "msg-1",
		FromAddress: "sender@example.com",
		Subject:     "Test",
		TextContent: "Hello",
	}
	data, err := json.Marshal(msg)
	require.NoError(t, err)
	assert.Contains(t, string(data), "msg-1")

	var decoded EmailMessage
	err = json.Unmarshal(data, &decoded)
	require.NoError(t, err)
	assert.Equal(t, msg.MessageID, decoded.MessageID)
}

func TestEmailAttachment_JSON_Cov4(t *testing.T) {
	att := EmailAttachment{
		Filename:    "doc.pdf",
		ContentType: "application/pdf",
		FileSize:    1024,
	}
	data, err := json.Marshal(att)
	require.NoError(t, err)
	assert.Contains(t, string(data), "doc.pdf")

	var decoded EmailAttachment
	err = json.Unmarshal(data, &decoded)
	require.NoError(t, err)
	assert.Equal(t, att.Filename, decoded.Filename)
}

// errReaderCov4 is a reader that always returns an error
type errReaderCov4 struct{}

func (e *errReaderCov4) Read(p []byte) (n int, err error) {
	return 0, assertErrorCov4("read error")
}

type errStringCov4 string

func (e errStringCov4) Error() string { return string(e) }

func assertErrorCov4(msg string) error {
	return errStringCov4(msg)
}

func jsonMarshal(v interface{}) ([]byte, error) {
	return json.Marshal(v)
}

func TestChannelpkgConstant_Cov4(t *testing.T) {
	// Ensure channelpkg import is used
	assert.Equal(t, "email", string(channelpkg.ChannelEmail))
}