/**
 * @file url.h
 * @brief Declaration for the URL
 */
#ifndef ADA_URL_H
#define ADA_URL_H

#include <algorithm>
#include <charconv>
#include <iostream>
#include <optional>
#include <string>
#include <string_view>

#include "ada/checkers.h"
#include "ada/common_defs.h"
#include "ada/log.h"
#include "ada/scheme.h"
#include "ada/serializers.h"
#include "ada/unicode.h"
#include "ada/url_base.h"
#include "ada/url_components.h"

namespace ada {

/**
 * @brief Generic URL struct reliant on std::string instantiation.
 *
 * @details To disambiguate from a valid URL string it can also be referred to
 * as a URL record. A URL is a struct that represents a universal identifier.
 * Unlike the url_aggregator, the ada::url represents the different components
 * of a parsed URL as independent std::string instances. This makes the
 * structure heavier and more reliant on memory allocations. When getting
 * components from the parsed URL, a new std::string is typically constructed.
 *
 * @see https://url.spec.whatwg.org/#url-representation
 */
struct url : url_base {
  url() = default;
  url(const url &u) = default;
  url(url &&u) noexcept = default;
  url &operator=(url &&u) noexcept = default;
  url &operator=(const url &u) = default;
  ~url() override = default;

  /**
   * @private
   * A URL's username is an ASCII string identifying a username. It is initially
   * the empty string.
   */
  std::string username{};

  /**
   * @private
   * A URL's password is an ASCII string identifying a password. It is initially
   * the empty string.
   */
  std::string password{};

  /**
   * @private
   * A URL's host is null or a host. It is initially null.
   */
  std::optional<std::string> host{};

  /**
   * @private
   * A URL's port is either null or a 16-bit unsigned integer that identifies a
   * networking port. It is initially null.
   */
  std::optional<uint16_t> port{};

  /**
   * @private
   * A URL's path is either an ASCII string or a list of zero or more ASCII
   * strings, usually identifying a location.
   */
  std::string path{};

  /**
   * @private
   * A URL's query is either null or an ASCII string. It is initially null.
   */
  std::optional<std::string> query{};

  /**
   * @private
   * 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.
   */
  std::optional<std::string> hash{};

  /** @return true if it has an host but it is the empty string */
  [[nodiscard]] inline bool has_empty_hostname() const noexcept;
  /** @return true if the URL has a (non default) port */
  [[nodiscard]] inline bool has_port() const noexcept;
  /** @return true if it has a host (included an empty host) */
  [[nodiscard]] inline bool has_hostname() const noexcept;
  [[nodiscard]] bool has_valid_domain() const noexcept override;

  /**
   * Returns a JSON string representation of this URL.
   */
  [[nodiscard]] std::string to_string() const override;

  /**
   * @see https://url.spec.whatwg.org/#dom-url-href
   * @see https://url.spec.whatwg.org/#concept-url-serializer
   */
  [[nodiscard]] ada_really_inline std::string get_href() const noexcept;

  /**
   * The origin getter steps are to return the serialization of this's URL's
   * origin. [HTML]
   * @return a newly allocated string.
   * @see https://url.spec.whatwg.org/#concept-url-origin
   */
  [[nodiscard]] std::string get_origin() const noexcept override;

  /**
   * The protocol getter steps are to return this's URL's scheme, followed by
   * U+003A (:).
   * @return a newly allocated string.
   * @see https://url.spec.whatwg.org/#dom-url-protocol
   */
  [[nodiscard]] std::string get_protocol() const noexcept;

  /**
   * Return url's host, serialized, followed by U+003A (:) and url's port,
   * serialized.
   * When there is no host, this function returns the empty string.
   * @return a newly allocated string.
   * @see https://url.spec.whatwg.org/#dom-url-host
   */
  [[nodiscard]] std::string get_host() const noexcept;

  /**
   * Return this's URL's host, serialized.
   * When there is no host, this function returns the empty string.
   * @return a newly allocated string.
   * @see https://url.spec.whatwg.org/#dom-url-hostname
   */
  [[nodiscard]] std::string get_hostname() const noexcept;

  /**
   * The pathname getter steps are to return the result of URL path serializing
   * this's URL.
   * @return a newly allocated string.
   * @see https://url.spec.whatwg.org/#dom-url-pathname
   */
  [[nodiscard]] std::string_view get_pathname() const noexcept;

  /**
   * Compute the pathname length in bytes without instantiating a view or a
   * string.
   * @return size of the pathname in bytes
   * @see https://url.spec.whatwg.org/#dom-url-pathname
   */
  [[nodiscard]] ada_really_inline size_t get_pathname_length() const noexcept;

  /**
   * Return U+003F (?), followed by this's URL's query.
   * @return a newly allocated string.
   * @see https://url.spec.whatwg.org/#dom-url-search
   */
  [[nodiscard]] std::string get_search() const noexcept;

  /**
   * The username getter steps are to return this's URL's username.
   * @return a constant reference to the underlying string.
   * @see https://url.spec.whatwg.org/#dom-url-username
   */
  [[nodiscard]] const std::string &get_username() const noexcept;

  /**
   * @return Returns true on successful operation.
   * @see https://url.spec.whatwg.org/#dom-url-username
   */
  bool set_username(std::string_view input);

  /**
   * @return Returns true on success.
   * @see https://url.spec.whatwg.org/#dom-url-password
   */
  bool set_password(std::string_view input);

  /**
   * @return Returns true on success.
   * @see https://url.spec.whatwg.org/#dom-url-port
   */
  bool set_port(std::string_view input);

  /**
   * This function always succeeds.
   * @see https://url.spec.whatwg.org/#dom-url-hash
   */
  void set_hash(std::string_view input);

  /**
   * This function always succeeds.
   * @see https://url.spec.whatwg.org/#dom-url-search
   */
  void set_search(std::string_view input);

  /**
   * @return Returns true on success.
   * @see https://url.spec.whatwg.org/#dom-url-search
   */
  bool set_pathname(std::string_view input);

  /**
   * @return Returns true on success.
   * @see https://url.spec.whatwg.org/#dom-url-host
   */
  bool set_host(std::string_view input);

  /**
   * @return Returns true on success.
   * @see https://url.spec.whatwg.org/#dom-url-hostname
   */
  bool set_hostname(std::string_view input);

  /**
   * @return Returns true on success.
   * @see https://url.spec.whatwg.org/#dom-url-protocol
   */
  bool set_protocol(std::string_view input);

  /**
   * @see https://url.spec.whatwg.org/#dom-url-href
   */
  bool set_href(std::string_view input);

  /**
   * The password getter steps are to return this's URL's password.
   * @return a constant reference to the underlying string.
   * @see https://url.spec.whatwg.org/#dom-url-password
   */
  [[nodiscard]] const std::string &get_password() const noexcept;

  /**
   * Return this's URL's port, serialized.
   * @return a newly constructed string representing the port.
   * @see https://url.spec.whatwg.org/#dom-url-port
   */
  [[nodiscard]] std::string get_port() const noexcept;

  /**
   * Return U+0023 (#), followed by this's URL's fragment.
   * @return a newly constructed string representing the hash.
   * @see https://url.spec.whatwg.org/#dom-url-hash
   */
  [[nodiscard]] std::string get_hash() const noexcept;

  /**
   * A URL includes credentials if its username or password is not the empty
   * string.
   */
  [[nodiscard]] ada_really_inline bool has_credentials() const noexcept;

  /**
   * Useful for implementing efficient serialization for the URL.
   *
   * https://user:pass@example.com:1234/foo/bar?baz#quux
   *       |     |    |          | ^^^^|       |   |
   *       |     |    |          | |   |       |   `----- hash_start
   *       |     |    |          | |   |       `--------- search_start
   *       |     |    |          | |   `----------------- pathname_start
   *       |     |    |          | `--------------------- port
   *       |     |    |          `----------------------- host_end
   *       |     |    `---------------------------------- host_start
   *       |     `--------------------------------------- username_end
   *       `--------------------------------------------- protocol_end
   *
   * Inspired after servo/url
   *
   * @return a newly constructed component.
   *
   * @see
   * https://github.com/servo/rust-url/blob/b65a45515c10713f6d212e6726719a020203cc98/url/src/quirks.rs#L31
   */
  [[nodiscard]] ada_really_inline ada::url_components get_components()
      const noexcept;
  /** @return true if the URL has a hash component */
  [[nodiscard]] inline bool has_hash() const noexcept override;
  /** @return true if the URL has a search component */
  [[nodiscard]] inline bool has_search() const noexcept override;

 private:
  friend ada::url ada::parser::parse_url<ada::url>(std::string_view,
                                                   const ada::url *);
  friend ada::url_aggregator ada::parser::parse_url<ada::url_aggregator>(
      std::string_view, const ada::url_aggregator *);
  friend void ada::helpers::strip_trailing_spaces_from_opaque_path<ada::url>(
      ada::url &url) noexcept;

  friend ada::url ada::parser::parse_url_impl<ada::url, true>(std::string_view,
                                                              const ada::url *);
  friend ada::url_aggregator ada::parser::parse_url_impl<
      ada::url_aggregator, true>(std::string_view, const ada::url_aggregator *);

  inline void update_unencoded_base_hash(std::string_view input);
  inline void update_base_hostname(std::string_view input);
  inline void update_base_search(std::string_view input);
  inline void update_base_search(std::string_view input,
                                 const uint8_t query_percent_encode_set[]);
  inline void update_base_search(std::optional<std::string> input);
  inline void update_base_pathname(std::string_view input);
  inline void update_base_username(std::string_view input);
  inline void update_base_password(std::string_view input);
  inline void update_base_port(std::optional<uint16_t> input);

  /**
   * Sets the host or hostname according to override condition.
   * Return true on success.
   * @see https://url.spec.whatwg.org/#hostname-state
   */
  template <bool override_hostname = false>
  bool set_host_or_hostname(std::string_view input);

  /**
   * Return true on success.
   * @see https://url.spec.whatwg.org/#concept-ipv4-parser
   */
  [[nodiscard]] bool parse_ipv4(std::string_view input);

  /**
   * Return true on success.
   * @see https://url.spec.whatwg.org/#concept-ipv6-parser
   */
  [[nodiscard]] bool parse_ipv6(std::string_view input);

  /**
   * Return true on success.
   * @see https://url.spec.whatwg.org/#concept-opaque-host-parser
   */
  [[nodiscard]] bool parse_opaque_host(std::string_view input);

  /**
   * 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. We only set non_special_scheme when the scheme
   * is non-special, otherwise we avoid constructing string.
   *
   * Special schemes are stored in ada::scheme::details::is_special_list so we
   * typically do not need to store them in each url instance.
   */
  std::string non_special_scheme{};

  /**
   * A URL cannot have a username/password/port if its host is null or the empty
   * string, or its scheme is "file".
   */
  [[nodiscard]] inline bool cannot_have_credentials_or_port() const;

  ada_really_inline size_t parse_port(
      std::string_view view, bool check_trailing_content) noexcept override;

  ada_really_inline size_t parse_port(std::string_view view) noexcept override {
    return this->parse_port(view, false);
  }

  /**
   * Take the scheme from another URL. The scheme string is copied from the
   * provided url.
   */
  inline void copy_scheme(const ada::url &u);

  /**
   * Parse the host from the provided input. We assume that
   * the input does not contain spaces or tabs. Control
   * characters and spaces are not trimmed (they should have
   * been removed if needed).
   * Return true on success.
   * @see https://url.spec.whatwg.org/#host-parsing
   */
  [[nodiscard]] ada_really_inline bool parse_host(std::string_view input);

  template <bool has_state_override = false>
  [[nodiscard]] ada_really_inline bool parse_scheme(std::string_view input);

  inline void clear_pathname() override;
  inline void clear_search() override;
  inline void set_protocol_as_file();

  /**
   * Parse the path from the provided input.
   * Return true on success. Control characters not
   * trimmed from the ends (they should have
   * been removed if needed).
   *
   * The input is expected to be UTF-8.
   *
   * @see https://url.spec.whatwg.org/
   */
  ada_really_inline void parse_path(std::string_view input);

  /**
   * Set the scheme for this URL. The provided scheme should be a valid
   * scheme string, be lower-cased, not contain spaces or tabs. It should
   * have no spurious trailing or leading content.
   */
  inline void set_scheme(std::string &&new_scheme) noexcept;

  /**
   * Take the scheme from another URL. The scheme string is moved from the
   * provided url.
   */
  inline void copy_scheme(ada::url &&u) noexcept;

};  // struct url

inline std::ostream &operator<<(std::ostream &out, const ada::url &u);
}  // namespace ada

#endif  // ADA_URL_H