/** \file complete.h
  Prototypes for functions related to tab-completion.

  These functions are used for storing and retrieving tab-completion
  data, as well as for performing tab-completion.
*/

#ifndef FISH_COMPLETE_H

/**
   Header guard
*/
#define FISH_COMPLETE_H


#include <wchar.h>
#include <stdint.h>

#include "util.h"
#include "common.h"
/**
 * Use all completions
 */
#define SHARED 0
/**
 * Do not use file completion
 */
#define NO_FILES 1
/**
 * Require a parameter after completion
 */
#define NO_COMMON 2
/**
 * Only use the argument list specifies with completion after
 * option. This is the same as (NO_FILES | NO_COMMON)
 */
#define EXCLUSIVE 3

/**
 * Command is a path
 */
#define PATH 1
/**
 * Command is not a path
 */
#define COMMAND 0

/**
 * Separator between completion and description
 */
#define COMPLETE_SEP L'\004'

/**
 * Separator between completion and description
 */
#define COMPLETE_SEP_STR L"\004"

/**
 * Character that separates the completion and description on
 * programmable completions
 */
#define PROG_COMPLETE_SEP L'\t'

enum
{
    /**
       Do not insert space afterwards if this is the only completion. (The
       default is to try insert a space)
    */
    COMPLETE_NO_SPACE = 1 << 0,

    /** This is not the suffix of a token, but replaces it entirely */
    COMPLETE_REPLACES_TOKEN = 1 << 2,

    /** This completion may or may not want a space at the end - guess by
       checking the last character of the completion. */
    COMPLETE_AUTO_SPACE = 1 << 3,

    /** This completion should be inserted as-is, without escaping. */
    COMPLETE_DONT_ESCAPE = 1 << 4,

    /** If you do escape, don't escape tildes */
    COMPLETE_DONT_ESCAPE_TILDES = 1 << 5
};
typedef int complete_flags_t;


class completion_t
{

private:
    /* No public default constructor */
    completion_t();
public:

    /* Destructor. Not inlining it saves code size. */
    ~completion_t();

    /** The completion string */
    wcstring completion;

    /** The description for this completion */
    wcstring description;

    /** The type of fuzzy match */
    string_fuzzy_match_t match;

    /**
       Flags determining the completion behaviour.

       Determines whether a space should be inserted after this
       completion if it is the only possible completion using the
       COMPLETE_NO_SPACE flag.

       The COMPLETE_NO_CASE can be used to signal that this completion
       is case insensitive.
    */
    complete_flags_t flags;

    /* Construction. Note: defining these so that they are not inlined reduces the executable size. */
    completion_t(const wcstring &comp, const wcstring &desc = wcstring(), string_fuzzy_match_t match = string_fuzzy_match_t(fuzzy_match_exact), complete_flags_t flags_val = 0);
    completion_t(const completion_t &);
    completion_t &operator=(const completion_t &);

    /* Compare two completions. No operating overlaoding to make this always explicit (there's potentially multiple ways to compare completions). */
    
    /* "Naturally less than" means in a natural ordering, where digits are treated as numbers. For example, foo10 is naturally greater than foo2 (but alphabetically less than it) */
    static bool is_naturally_less_than(const completion_t &a, const completion_t &b);
    static bool is_alphabetically_equal_to(const completion_t &a, const completion_t &b);
};

enum
{
    COMPLETION_REQUEST_DEFAULT = 0,
    COMPLETION_REQUEST_AUTOSUGGESTION = 1 << 0, // indicates the completion is for an autosuggestion
    COMPLETION_REQUEST_DESCRIPTIONS = 1 << 1, // indicates that we want descriptions
    COMPLETION_REQUEST_FUZZY_MATCH = 1 << 2 // indicates that we don't require a prefix match
};
typedef uint32_t completion_request_flags_t;

/**

  Add a completion.

  All supplied values are copied, they should be freed by or otherwise
  disposed by the caller.

  Examples:

  The command 'gcc -o' requires that a file follows it, so the
  NO_COMMON option is suitable. This can be done using the following
  line:

  complete -c gcc -s o -r

  The command 'grep -d' required that one of the strings 'read',
  'skip' or 'recurse' is used. As such, it is suitable to specify that
  a completion requires one of them. This can be done using the
  following line:

  complete -c grep -s d -x -a "read skip recurse"


  \param cmd Command to complete.
  \param cmd_type If cmd_type is PATH, cmd will be interpreted as the absolute
      path of the program (optionally containing wildcards), otherwise it
      will be interpreted as the command name.
  \param short_opt The single character name of an option. (-a is a short option,
      --all and  -funroll are long options)
  \param long_opt The multi character name of an option. (-a is a short option,
      --all and  -funroll are long options)
  \param long_mode Whether to use old style, single dash long options.
  \param result_mode Whether to search further completions when this
      completion has been succesfully matched. If result_mode is SHARED,
      any other completions may also be used. If result_mode is NO_FILES,
      file completion should not be used, but other completions may be
      used. If result_mode is NO_COMMON, on option may follow it - only a
      parameter. If result_mode is EXCLUSIVE, no option may follow it, and
      file completion is not performed.
  \param comp A space separated list of completions which may contain subshells.
  \param desc A description of the completion.
  \param condition a command to be run to check it this completion should be used.
      If \c condition is empty, the completion is always used.
  \param flags A set of completion flags
*/
void complete_add(const wchar_t *cmd,
                  bool cmd_is_path,
                  wchar_t short_opt,
                  const wchar_t *long_opt,
                  int long_mode,
                  int result_mode,
                  const wchar_t *condition,
                  const wchar_t *comp,
                  const wchar_t *desc,
                  int flags);
/**
  Sets whether the completion list for this command is complete. If
  true, any options not matching one of the provided options will be
  flagged as an error by syntax highlighting.
*/
void complete_set_authoritative(const wchar_t *cmd, bool cmd_type, bool authoritative);

/**
  Remove a previously defined completion
*/
void complete_remove(const wchar_t *cmd,
                     bool cmd_is_path,
                     wchar_t short_opt,
                     const wchar_t *long_opt,
                     int long_mode);


/** Find all completions of the command cmd, insert them into out.
 */
void complete(const wcstring &cmd,
              std::vector<completion_t> &comp,
              completion_request_flags_t flags);

/**
   Print a list of all current completions into the string.

   \param out The string to write completions to
*/
void complete_print(wcstring &out);

/**
   Tests if the specified option is defined for the specified command
*/
int complete_is_valid_option(const wcstring &str,
                             const wcstring &opt,
                             wcstring_list_t *inErrorsOrNull,
                             bool allow_autoload);

/**
   Tests if the specified argument is valid for the specified option
   and command
*/
bool complete_is_valid_argument(const wcstring &str,
                                const wcstring &opt,
                                const wcstring &arg);


/**
   Load command-specific completions for the specified command. This
   is done automatically whenever completing any given command, so
   there is no need to call this except in the case of completions
   with internal dependencies.

   \param cmd the command for which to load command-specific completions
   \param reload should the commands completions be reloaded, even if they where
      previously loaded. (This is set to true on actual completions, so that
      changed completion are updated in running shells)
*/
void complete_load(const wcstring &cmd, bool reload);

/**
   Create a new completion entry

   \param completions The array of completions to append to
   \param comp The completion string
   \param desc The description of the completion
   \param flags completion flags

*/
void append_completion(std::vector<completion_t> &completions, const wcstring &comp, const wcstring &desc = wcstring(), int flags = 0, string_fuzzy_match_t match = string_fuzzy_match_t(fuzzy_match_exact));

/* Function used for testing */
void complete_set_variable_names(const wcstring_list_t *names);

/* Support for "wrap targets." A wrap target is a command that completes liek another command. The target chain is the sequence of wraps (A wraps B wraps C...). Any loops in the chain are silently ignored. */
bool complete_add_wrapper(const wcstring &command, const wcstring &wrap_target);
bool complete_remove_wrapper(const wcstring &command, const wcstring &wrap_target);
wcstring_list_t complete_get_wrap_chain(const wcstring &command);

/* Wonky interface: returns all wraps. Even-values are the commands, odd values are the targets. */
wcstring_list_t complete_get_wrap_pairs();

#endif