/*

 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>

 * Copyright (c) 2021, Max Wipfli <mail@maxwipfli.ch>

 * Copyright (c) 2023-2024, Shannon Booth <shannon@serenityos.org>

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#pragma once

#include <AK/ByteString.h>

#include <AK/CopyOnWrite.h>

#include <AK/String.h>

#include <AK/StringView.h>

#include <AK/Vector.h>

#include <LibURL/Host.h>

#include <LibURL/Origin.h>

// On Linux distros that use mlibc `basename` is defined as a macro that expands to `__mlibc_gnu_basename` or `__mlibc_gnu_basename_c`, so we undefine it.

#if defined(AK_OS_LINUX) && defined(basename)

#    undef basename

#endif

namespace URL {

enum class PercentEncodeSet {

    C0Control,

    Fragment,

    Query,

    SpecialQuery,

    Path,

    Userinfo,

    Component,

    ApplicationXWWWFormUrlencoded,

    EncodeURI

};

enum class ExcludeFragment {

    No,

    Yes

};

// https://w3c.github.io/FileAPI/#blob-url-entry

// NOTE: This represents the raw bytes behind a 'Blob' (and does not yet support a MediaSourceQuery).

struct BlobURLEntry {

    String type;

    ByteBuffer byte_buffer;

    Origin environment_origin;

};

void append_percent_encoded_if_necessary(StringBuilder&, u32 code_point, PercentEncodeSet set = PercentEncodeSet::Userinfo);

void append_percent_encoded(StringBuilder&, u32 code_point);

bool code_point_is_in_percent_encode_set(u32 code_point, PercentEncodeSet);

Optional<u16> default_port_for_scheme(StringView);

bool is_special_scheme(StringView);

enum class SpaceAsPlus {

    No,

    Yes,

};

String percent_encode(StringView input, PercentEncodeSet set = PercentEncodeSet::Userinfo, SpaceAsPlus = SpaceAsPlus::No);

ByteString percent_decode(StringView input);

// https://url.spec.whatwg.org/#url-representation

// A URL is a struct that represents a universal identifier. To disambiguate from a valid URL string it can also be referred to as a URL record.

class URL {

    friend class Parser;

public:

    URL() = default;

    URL(StringView);

    URL(ByteString const& string)

        : URL(string.view())

    {

    }

    URL(String const& string)

        : URL(string.bytes_as_string_view())

    {

    }

    bool is_valid() const { return m_data->valid; }

    String const& scheme() const { return m_data->scheme; }

    String const& username() const { return m_data->username; }

    String const& password() const { return m_data->password; }

    Host const& host() const { return m_data->host; }

    ErrorOr<String> serialized_host() const;

    ByteString basename() const;

    Optional<String> const& query() const { return m_data->query; }

    Optional<String> const& fragment() const { return m_data->fragment; }

    Optional<u16> port() const { return m_data->port; }

    ByteString path_segment_at_index(size_t index) const;

    size_t path_segment_count() const { return m_data->paths.size(); }

    u16 port_or_default() const { return m_data->port.value_or(default_port_for_scheme(m_data->scheme).value_or(0)); }

    bool cannot_be_a_base_url() const { return m_data->cannot_be_a_base_url; }

    bool cannot_have_a_username_or_password_or_port() const;

    bool includes_credentials() const { return !m_data->username.is_empty() || !m_data->password.is_empty(); }

    bool is_special() const { return is_special_scheme(m_data->scheme); }

    void set_scheme(String);

    void set_username(StringView);

    void set_password(StringView);

    void set_host(Host);

    void set_port(Optional<u16>);

    void set_paths(Vector<ByteString> const&);

    Vector<String> const& paths() const { return m_data->paths; }

    void set_query(Optional<String> query) { m_data->query = move(query); }

    void set_fragment(Optional<String> fragment) { m_data->fragment = move(fragment); }

    void set_cannot_be_a_base_url(bool value) { m_data->cannot_be_a_base_url = value; }

    void append_path(StringView);

    void append_slash()

    {

        // NOTE: To indicate that we want to end the path with a slash, we have to append an empty path segment.

        m_data->paths.append(String {});

    }

    String serialize_path() const;

    ByteString serialize(ExcludeFragment = ExcludeFragment::No) const;

    ByteString serialize_for_display() const;

    ByteString to_byte_string() const { return serialize(); }

    ErrorOr<String> to_string() const;

    Origin origin() const;

    bool equals(URL const& other, ExcludeFragment = ExcludeFragment::No) const;

    URL complete_url(StringView) const;

    [[nodiscard]] bool operator==(URL const& other) const

    {

        if (m_data.ptr() == other.m_data.ptr())

            return true;

        return equals(other, ExcludeFragment::No);

    }

    Optional<BlobURLEntry> const& blob_url_entry() const { return m_data->blob_url_entry; }

    void set_blob_url_entry(Optional<BlobURLEntry> entry) { m_data->blob_url_entry = move(entry); }

private:

    bool compute_validity() const;

    struct Data : public RefCounted<Data> {

        NonnullRefPtr<Data> clone()

        {

            auto clone = adopt_ref(*new Data);

            clone->valid = valid;

            clone->scheme = scheme;

            clone->username = username;

            clone->password = password;

            clone->host = host;

            clone->port = port;

            clone->paths = paths;

            clone->query = query;

            clone->fragment = fragment;

            clone->cannot_be_a_base_url = cannot_be_a_base_url;

            clone->blob_url_entry = blob_url_entry;

            return clone;

        }

        bool valid { false };

        // A URL’s scheme is an ASCII string that identifies the type of URL and can be used to dispatch a URL for further processing after parsing. It is initially the empty string.

        String scheme;

        // A URL’s username is an ASCII string identifying a username. It is initially the empty string.

        String username;

        // A URL’s password is an ASCII string identifying a password. It is initially the empty string.

        String password;

        // A URL’s host is null or a host. It is initially null.

        Host host;

        // A URL’s port is either null or a 16-bit unsigned integer that identifies a networking port. It is initially null.

        Optional<u16> port;

        // A URL’s path is either a URL path segment or a list of zero or more URL path segments, usually identifying a location. It is initially « ».

        // A URL path segment is an ASCII string. It commonly refers to a directory or a file, but has no predefined meaning.

        Vector<String> paths;

        // A URL’s query is either null or an ASCII string. It is initially null.

        Optional<String> query;

        // A URL’s fragment is either null or an ASCII string that can be used for further processing on the resource the URL’s other components identify. It is initially null.

        Optional<String> fragment;

        bool cannot_be_a_base_url { false };

        // https://url.spec.whatwg.org/#concept-url-blob-entry

        // A URL also has an associated blob URL entry that is either null or a blob URL entry. It is initially null.

        Optional<BlobURLEntry> blob_url_entry;

    };

    AK::CopyOnWrite<Data> m_data;

};

URL create_with_url_or_path(ByteString const&);

URL create_with_file_scheme(ByteString const& path, ByteString const& fragment = {}, ByteString const& hostname = {});

URL create_with_help_scheme(ByteString const& path, ByteString const& fragment = {}, ByteString const& hostname = {});

URL create_with_data(StringView mime_type, StringView payload, bool is_base64 = false);

}

template<>

struct AK::Formatter<URL::URL> : AK::Formatter<StringView> {

    ErrorOr<void> format(FormatBuilder& builder, URL::URL const& value)

    {

        return Formatter<StringView>::format(builder, value.serialize());

    }

};

template<>

struct AK::Traits<URL::URL> : public AK::DefaultTraits<URL::URL> {

    static unsigned hash(URL::URL const& url) { return url.to_byte_string().hash(); }

};