#include "vdm/net/content_disposition.hpp"

#include <string>
#include <string_view>

#include "vtest.hpp"

using vdm::net::ContentDisposition;
using vdm::net::parse_content_disposition;
using Type = vdm::net::ContentDisposition::Type;

namespace {
// "€" is U+20AC -> UTF-8 E2 82 AC. "£" is U+00A3 -> UTF-8 C2 A3.
const std::string kEuro = "\xE2\x82\xAC";
const std::string kPound = "\xC2\xA3";
const std::string kEAcute = "\xC3\xA9";  // é U+00E9
}  // namespace

VT_TEST(cd_plain_quoted) {
    auto cd = parse_content_disposition(R"(attachment; filename="report.pdf")");
    VT_CHECK(cd.type == Type::attachment);
    VT_CHECK_EQ(cd.filename, std::string("report.pdf"));
    VT_CHECK(!cd.filename_from_ext);
}

VT_TEST(cd_plain_token_unquoted) {
    auto cd = parse_content_disposition("attachment; filename=report.pdf");
    VT_CHECK_EQ(cd.filename, std::string("report.pdf"));
}

VT_TEST(cd_inline_no_filename) {
    auto cd = parse_content_disposition("inline");
    VT_CHECK(cd.type == Type::inline_);
    VT_CHECK(!cd.has_filename());
}

VT_TEST(cd_rfc5987_utf8_ext_value) {
    auto cd = parse_content_disposition("attachment; filename*=UTF-8''%e2%82%ac%20rates.pdf");
    VT_CHECK_EQ(cd.filename, kEuro + " rates.pdf");
    VT_CHECK(cd.filename_from_ext);
}

VT_TEST(cd_prefers_ext_over_plain) {
    auto cd = parse_content_disposition(
        R"(attachment; filename="EURO rates.pdf"; filename*=UTF-8''%e2%82%ac%20rates.pdf)");
    VT_CHECK_EQ(cd.filename, kEuro + " rates.pdf");
    VT_CHECK(cd.filename_from_ext);
}

VT_TEST(cd_rfc5987_latin1_ext_value) {
    // %A3 = £ in ISO-8859-1
    auto cd = parse_content_disposition("attachment; filename*=ISO-8859-1''%A3rates.pdf");
    VT_CHECK_EQ(cd.filename, kPound + "rates.pdf");
}

VT_TEST(cd_legacy_rfc2047_base64) {
    // base64("<euro> rates.pdf") with euro as UTF-8
    // "€ rates.pdf" -> bytes E2 82 AC 20 72 61 74 65 73 2E 70 64 66 -> base64:
    auto cd =
        parse_content_disposition(R"(attachment; filename="=?UTF-8?B?4oKsIHJhdGVzLnBkZg==?=")");
    VT_CHECK_EQ(cd.filename, kEuro + " rates.pdf");
}

VT_TEST(cd_legacy_rfc2047_qencoded_latin1) {
    // =?ISO-8859-1?Q?=A3rates.pdf?=  -> £rates.pdf
    auto cd = parse_content_disposition(R"(attachment; filename="=?ISO-8859-1?Q?=A3rates.pdf?=")");
    VT_CHECK_EQ(cd.filename, kPound + "rates.pdf");
}

VT_TEST(cd_raw_utf8_bytes_in_quotes) {
    std::string h = "attachment; filename=\"caf" + kEAcute + ".txt\"";
    auto cd = parse_content_disposition(h);
    VT_CHECK_EQ(cd.filename, "caf" + kEAcute + ".txt");
}

VT_TEST(cd_raw_latin1_byte_in_quotes) {
    // 0xE9 is 'é' in Latin-1; not valid UTF-8 alone -> transcoded
    std::string h = "attachment; filename=\"caf\xE9.txt\"";
    auto cd = parse_content_disposition(h);
    VT_CHECK_EQ(cd.filename, "caf" + kEAcute + ".txt");
}

VT_TEST(cd_strips_path_components) {
    VT_CHECK_EQ(parse_content_disposition(R"(attachment; filename="../../etc/passwd")").filename,
                std::string("passwd"));
    // real Windows paths in the wild use unescaped backslashes as separators
    VT_CHECK_EQ(parse_content_disposition(R"(attachment; filename="C:\Windows\evil.exe")").filename,
                std::string("evil.exe"));
    // a base64 payload can contain '/', so decode must happen before path stripping
    VT_CHECK_EQ(parse_content_disposition(R"(attachment; filename="=?UTF-8?B?Li4vLi4vc2VjcmV0?=")")
                    .filename,
                std::string("secret"));  // decodes to "../../secret", then stripped
}

VT_TEST(cd_quoted_dquote_escape) {
    // \" is the one escape we resolve, so a quote can appear mid-name
    auto cd = parse_content_disposition(R"(attachment; filename="quote\"here.txt")");
    VT_CHECK_EQ(cd.filename, std::string("quote\"here.txt"));
}

VT_TEST(cd_semicolon_inside_quotes_is_not_a_separator) {
    auto cd = parse_content_disposition(R"(attachment; filename="a;b;c.txt")");
    VT_CHECK_EQ(cd.filename, std::string("a;b;c.txt"));
}

VT_TEST(cd_form_data) {
    auto cd = parse_content_disposition(R"(form-data; name="file"; filename="upload.bin")");
    VT_CHECK(cd.type == Type::form_data);
    VT_CHECK_EQ(cd.filename, std::string("upload.bin"));
}

VT_TEST(cd_rfc2231_continuations) {
    auto cd = parse_content_disposition(
        "attachment; filename*0*=UTF-8''%e2%82%ac; filename*1*=%20rates; filename*2=.pdf");
    VT_CHECK_EQ(cd.filename, kEuro + " rates.pdf");
}

VT_TEST(cd_empty_and_garbage_do_not_crash) {
    VT_CHECK(!parse_content_disposition("").has_filename());
    VT_CHECK(!parse_content_disposition(";;;;").has_filename());
    VT_CHECK(!parse_content_disposition("attachment;").has_filename());
    VT_CHECK(!parse_content_disposition(R"(attachment; filename=)").has_filename());
    VT_CHECK(!parse_content_disposition(R"(attachment; filename="")").has_filename());
    // truncated ext-value
    auto cd = parse_content_disposition("attachment; filename*=UTF-8''%e2%82");
    VT_CHECK(cd.type == Type::attachment);  // no crash; filename is whatever fell out
    // truncated encoded-word
    auto trunc = parse_content_disposition(R"(attachment; filename="=?UTF-8?B?4oKs")");
    (void)trunc;
}

VT_TEST(cd_bad_percent_escapes_in_ext_value) {
    // stray % and non-hex digits are emitted literally, no crash
    auto cd = parse_content_disposition("attachment; filename*=UTF-8''%ZZ%%file%2");
    VT_CHECK(cd.type == Type::attachment);
}

VT_TEST(cd_case_insensitive_keys_and_type) {
    auto cd = parse_content_disposition(R"(ATTACHMENT; FileName="x.txt")");
    VT_CHECK(cd.type == Type::attachment);
    VT_CHECK_EQ(cd.filename, std::string("x.txt"));
}

VT_TEST(cd_unknown_type_is_other) {
    auto cd = parse_content_disposition(R"(signal; filename="x.txt")");
    VT_CHECK(cd.type == Type::other);
    VT_CHECK_EQ(cd.filename, std::string("x.txt"));
}