package dispatch

import (
	"testing"

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

func TestValidateFromAddr(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name               string
		input              string
		expectedEnvelope   string
		expectedHeader     string
		expectedErrContain string
	}{
		{
			name:             "bare email address",
			input:            "system@coder.com",
			expectedEnvelope: "system@coder.com",
			expectedHeader:   "system@coder.com",
		},
		{
			name:             "email with display name",
			input:            "Coder System <system@coder.com>",
			expectedEnvelope: "system@coder.com",
			expectedHeader:   "Coder System <system@coder.com>",
		},
		{
			name:             "email with quoted display name",
			input:            `"Coder Notifications" <notifications@coder.com>`,
			expectedEnvelope: "notifications@coder.com",
			expectedHeader:   `"Coder Notifications" <notifications@coder.com>`,
		},
		{
			name:             "email with special characters in display name",
			input:            `"O'Brien, John" <john@example.com>`,
			expectedEnvelope: "john@example.com",
			expectedHeader:   `"O'Brien, John" <john@example.com>`,
		},
		{
			name:               "invalid email address",
			input:              "not-an-email",
			expectedErrContain: "parse 'from' address",
		},
		{
			name:               "empty string",
			input:              "",
			expectedErrContain: "parse 'from' address",
		},
		{
			name:               "multiple addresses",
			input:              "a@example.com, b@example.com",
			expectedErrContain: "'from' address not defined",
		},
	}

	handler := &SMTPHandler{}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()

			envelope, header, err := handler.validateFromAddr(tc.input)

			if tc.expectedErrContain != "" {
				require.Error(t, err)
				require.ErrorContains(t, err, tc.expectedErrContain)
				return
			}

			require.NoError(t, err)
			require.Equal(t, tc.expectedEnvelope, envelope,
				"envelope address should be the bare email")
			require.Equal(t, tc.expectedHeader, header,
				"header address should preserve the original input")
		})
	}
}