Module:string

local m_params = require("Module:paramètres")
local str = {}

-- Cannot include null byte.
local UTF8_char = "*"

str.diacriticsTable = {
	 = "a",
	 = "a",
	 = "a",
	 = "a",
	 = "a",
	 = "c",
	 = "e",
	 = "e",
	 = "e",
	 = "e",
	 = "i",
	 = "i",
	 = "i",
	 = "i",
	 = "n",
	 = "oe",
	 = "o",
	 = "o",
	 = "o",
	 = "o",
	 = "o",
	 = "u",
	 = "u",
	 = "u",
	 = "u",
	 = "y",
	 = "y",
}

-- Remove the diacritics of the given string s
function str.undiacritize(s)
	return s:gsub("*", str.diacriticsTable)	
end

--[[
ulen

Counts UTF-8 characters. Faster than mw.ustring.len.

Assumes that the encoding is correct. Unlike mw.ustring.len, does not return nil
if encoding is invalid.

Does not count the bytes 192, 193, and 245-255. They are not used in UTF-8 and
will not occur if the string is valid. They are replaced with the replacement
character (U+FFFD) on MediaWiki pages.
--]]
function str.ulen(text)
  local _, length = string.gsub(text, UTF8_char, "")
  return length
end

--[[
len

This function returns the length of the target string.

Usage:
{{#invoke:string|len|target_string|}}
OR
{{#invoke:string|len|s=target_string}}

Parameters
    s: The string whose length to report

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the target string.
]]
function str.len(frame)
  local new_args = str._getParameters(frame.args, { 's' });
  local s = new_args or '';
  return mw.ustring.len(s)
end

--[[
sub

This function returns a substring of the target string at specified indices.

Usage:
{{#invoke:string|sub|target_string|start_index|end_index}}
OR
{{#invoke:string|sub|s=target_string|i=start_index|j=end_index}}

Parameters
    s: The string to return a subset of
    i: The fist index of the substring to return, defaults to 1.
    j: The last index of the string to return, defaults to the last character.
    
The first character of the string is assigned an index of 1.  If either i or j
is a negative value, it is interpreted the same as selecting a character by
counting from the end of the string.  Hence, a value of -1 is the same as
selecting the last character of the string.

If the requested indices are out of range for the given string, an error is
reported.
]]
function str.sub(frame)
  local new_args = str._getParameters(frame.args, { 's', 'i', 'j' });
  local s = new_args or '';
  local i = tonumber(new_args) or 1;
  local j = tonumber(new_args) or -1;

  local len = mw.ustring.len(s);

  -- Convert negatives for range checking
  if i < 0 then
    i = len + i + 1;
  end
  if j < 0 then
    j = len + j + 1;
  end

  if i > len or j > len or i < 1 or j < 1 then
    return str._error('String subset index out of range');
  end
  if j < i then
    return str._error('String subset indices out of order');
  end

  return mw.ustring.sub(s, i, j)
end

--[[
This function implements that features of {{str sub old}} and is kept in order
to maintain these older templates.
]]
function str.sublength(frame)
  local i = tonumber(frame.args.i) or 0
  local len = tonumber(frame.args.len)
  return mw.ustring.sub(frame.args.s, i + 1, len and (i + len))
end

--[[
match

This function returns a substring from the source string that matches a
specified pattern.

Usage:
{{#invoke:string|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}
OR
{{#invoke:string|pos|s=source_string|pattern=pattern_string|start=start_index
    |match=match_number|plain=plain_flag|nomatch=nomatch_output}}

Parameters
    s: The string to search
    pattern: The pattern or string to find within the string
    start: The index within the source string to start the search.  The first
        character of the string has index 1.  Defaults to 1.
    match: In some cases it may be possible to make multiple matches on a single
        string.  This specifies which match to return, where the first match is
        match= 1.  If a negative number is specified then a match is returned
        counting from the last match.  Hence match = -1 is the same as requesting
        the last match.  Defaults to 1.
    plain: A flag indicating that the pattern should be understood as plain
        text.  Defaults to false.
    nomatch: If no match is found, output the "nomatch" value rather than an error.

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from each string.  In some circumstances this is desirable, in
other cases one may want to preserve the whitespace.

If the match_number or start_index are out of range for the string being queried, then
this function generates an error.  An error is also generated if no match is found.
If one adds the parameter ignore_errors=true, then the error will be suppressed and
an empty string will be returned on any failure.

For information on constructing Lua patterns, a form of , see:

* http://www.lua.org/manual/5.1/manual.html#5.4.1
* http://www.mediawiki.orghttps://dictious.com/fr/Extension:Scribunto/Lua_reference_manual#Patterns
* http://www.mediawiki.orghttps://dictious.com/fr/Extension:Scribunto/Lua_reference_manual#Ustring_patterns

]]
function str.match(frame)
  local new_args = str._getParameters(frame.args, { 's', 'pattern', 'start', 'match', 'plain', 'nomatch' });
  local s = new_args or '';
  local start = tonumber(new_args) or 1;
  local plain_flag = str._getBoolean(new_args or false);
  local pattern = new_args or '';
  local match_index = math.floor(tonumber(new_args) or 1);
  local nomatch = new_args;

  if s == '' then
    return str._error('Target string is empty');
  end
  if pattern == '' then
    return str._error('Pattern string is empty');
  end
  if math.abs(start) < 1 or math.abs(start) > mw.ustring.len(s) then
    return str._error('Requested start is out of range');
  end
  if match_index == 0 then
    return str._error('Match index is out of range');
  end
  if plain_flag then
    pattern = str.pattern_escape(pattern);
  end

  local result
  if match_index == 1 then
    -- Find first match is simple case
    result = mw.ustring.match(s, pattern, start)
  else
    if start > 1 then
      s = mw.ustring.sub(s, start);
    end

    local iterator = mw.ustring.gmatch(s, pattern);
    if match_index > 0 then
      -- Forward search
      for w in iterator do
        match_index = match_index - 1;
        if match_index == 0 then
          result = w;
          break;
        end
      end
    else
      -- Reverse search
      local result_table = {};
      local count = 1;
      for w in iterator do
        result_table = w;
        count = count + 1;
      end

      result = result_table;
    end
  end

  if result == nil then
    if nomatch == nil then
      return str._error('Match not found');
    else
      return nomatch;
    end
  else
    return result;
  end
end

--[[
pos

This function returns a single character from the target string at position pos.

Usage:
{{#invoke:string|pos|target_string|index_value}}
OR
{{#invoke:string|pos|target=target_string|pos=index_value}}

Parameters
    target: The string to search
    pos: The index for the character to return

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the target string.  In some circumstances this is desirable, in
other cases one may want to preserve the whitespace.

The first character has an index value of 1.

If one requests a negative value, this function will select a character by counting backwards
from the end of the string.  In other words pos = -1 is the same as asking for the last character.

A requested value of zero, or a value greater than the length of the string returns an error.
]]
function str.pos(frame)
  local new_args = str._getParameters(frame.args, { 'target', 'pos' });
  local target_str = new_args or '';
  local pos = tonumber(new_args) or 0;

  if pos == 0 or math.abs(pos) > mw.ustring.len(target_str) then
    return str._error('String index out of range');
  end

  return mw.ustring.sub(target_str, pos, pos);
end

--[[
str_find

This function duplicates the behavior of {{str_find}}, including all of its quirks.
This is provided in order to support existing templates, but is NOT RECOMMENDED for
new code and templates.  New code is recommended to use the "find" function instead.

Returns the first index in "source" that is a match to "target".  Indexing is 1-based,
and the function returns -1 if the "target" string is not present in "source".

Important Note: If the "target" string is empty / missing, this function returns a
value of "1", which is generally unexpected behavior, and must be accounted for
separatetly.
]]
function str.str_find(frame)
  local new_args = str._getParameters(frame.args, { 'source', 'target' });
  local source_str = new_args or '';
  local target_str = new_args or '';

  if target_str == '' then
    return 1;
  end

  local start = mw.ustring.find(source_str, target_str, 1, true)
  if start == nil then
    start = -1
  end

  return start
end

--[[
find

This function allows one to search for a target string or pattern within another
string.

Usage:
{{#invoke:string|find|source_str|target_string|start_index|plain_flag}}
OR
{{#invoke:string|find|source=source_str|target=target_str|start=start_index|plain=plain_flag}}

Parameters
    source: The string to search
    target: The string or pattern to find within source
    start: The index within the source string to start the search, defaults to 1
    plain: Boolean flag indicating that target should be understood as plain
        text and not as a Lua style regular expression, defaults to true

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the parameter.  In some circumstances this is desirable, in
other cases one may want to preserve the whitespace.

This function returns the first index >= "start" where "target" can be found
within "source".  Indices are 1-based.  If "target" is not found, then this
function returns an empty string.  If either "source" or "target" are missing / empty, this
function also returns an empty string.

This function should be safe for UTF-8 strings.
]]
function str.find(frame)
  local params = {
     = { required = true },
     = { required = true },
     = { type = "int" },
     = { type = "boolean" },
  }

  local args = m_params.process(frame.args, params)

  return mw.ustring.find(args, args, args, args)
end

--[[
replace

This function allows one to replace a target string or pattern within another
string.

Usage:
{{#invoke:string|replace|source_str|pattern_string|replace_string|replacement_count|plain_flag}}
OR
{{#invoke:string|replace|source=source_string|pattern=pattern_string|replace=replace_string|
   count=replacement_count|plain=plain_flag}}

Parameters
    source: The string to search
    pattern: The string or pattern to find within source
    replace: The replacement text
    count: The number of occurences to replace, defaults to all.
    plain: Boolean flag indicating that pattern should be understood as plain
        text and not as a Lua style regular expression, defaults to true
]]
function str.replace(frame)
  local new_args = str._getParameters(frame.args, { 'source', 'pattern', 'replace', 'count', 'plain' });
  local source_str = new_args or '';
  local pattern = new_args or '';
  local replace = new_args or '';
  local count = tonumber(new_args);
  local plain = new_args or true;

  if source_str == '' or pattern == '' then
    return source_str;
  end
  plain = str._getBoolean(plain);

  if plain then
    pattern = str.pattern_escape(pattern);
    replace = mw.ustring.gsub(replace, "%%", "%%%%"); --Only need to escape replacement sequences.
  end

  local result;

  if count ~= nil then
    result = mw.ustring.gsub(source_str, pattern, replace, count);
  else
    result = mw.ustring.gsub(source_str, pattern, replace);
  end

  return result;
end


function str.gsub(frame)
  local params = {
     = { required = true, allow_empty = true },
     = { required = true, allow_empty = true },
     = { required = true, allow_empty = true },
     = { type = "int" },
  }

  local args = m_params.process(frame.args, params)

  return (mw.ustring.gsub(args, args, args, args))
end


--[[
    simple function to pipe string.rep to templates.
]]

function str.rep(frame)
  local repetitions = tonumber(frame.args)
  if not repetitions then
    return str._error('function rep expects a number as second parameter, received "' .. (frame.args or '') .. '"')
  end
  return string.rep(frame.args or '', repetitions)
end

function str.lower(frame)
  local text = frame.args or ''
  return mw.ustring.lower(text)
end

str.lc = str.lower

--[[
Helper function that populates the argument list given that user may need to use a mix of
named and unnamed parameters.  This is relevant because named parameters are not
identical to unnamed parameters due to string trimming, and when dealing with strings
we sometimes want to either preserve or remove that whitespace depending on the application.
]]
function str._getParameters(frame_args, arg_list)
  local new_args = {};
  local index = 1;
  local value;

  for _, arg in ipairs(arg_list) do
    value = frame_args
    if value == nil then
      value = frame_args;
      index = index + 1;
    end
    new_args = value;
  end

  return new_args;
end

--[[
Helper function to handle error messages.
]]
function str._error(error_str)
  local frame = mw.getCurrentFrame();
  local error_category = frame.args.error_category or 'Errors reported by Module String';
  local ignore_errors = frame.args.ignore_errors or false;
  local no_category = frame.args.no_category or false;

  if str._getBoolean(ignore_errors) then
    return '';
  end

  error_str = '<strong class="error">String Module Error: ' .. error_str .. '</strong>';
  if error_category ~= '' and not str._getBoolean(no_category) then
    error_str = ']' .. error_str;
  end

  return error_str;
end

--[[
Helper Function to interpret boolean strings
]]
function str._getBoolean(boolean_str)
  local boolean_value;

  if type(boolean_str) == 'string' then
    boolean_str = boolean_str:lower();
    if boolean_str == 'false' or boolean_str == 'no' or boolean_str == '0'
        or boolean_str == '' then
      boolean_value = false;
    else
      boolean_value = true;
    end
  elseif type(boolean_str) == 'boolean' then
    boolean_value = boolean_str;
  else
    error('No boolean value found');
  end
  return boolean_value
end

--[[
Helper function that escapes all pattern characters – ().%+-*? – so that they will be treated
as plain text.
]]
function str.pattern_escape(pattern_str)
  local invoked = false

  if type(pattern_str) == "table" then
    if pattern_str.args then
      local frame = pattern_str
      invoked = true

      if frame.args then
        pattern_str = frame.args
      else
        pattern_str = frame:getParent().args
      end
    else
      error("First argument to pattern_escape should be a string, a number, or a frame object.")
    end
  elseif not (type(pattern_str) == "string" or type(pattern_str) == "number") then
    error("First argument to pattern_escape should be a string or a number.")
  end

  if invoked then
    local escaped = mw.ustring.gsub(pattern_str, "(])", "%%%1")
    return escaped
  else
    return mw.ustring.gsub(pattern_str, "(])", "%%%1");
  end
end

function str.count(text, pattern, plain)
  if not (type(text) == "string" or type(text) == "number") then
    error('The first argument to the function "count" must be a string or a number, not a ' .. type(text) .. '.')
  end

  if not (type(pattern) == "string" or type(pattern) == "number") then
    error('The first argument to the function "count" must be a string or a number, not a ' .. type(text) .. '.')
  end

  if plain then
    pattern = str.pattern_escape(pattern)
  end

  local _, count = mw.ustring.gsub(text, pattern, "")

  return count
end

function str.plain_gsub(text, pattern, replacement)
  local invoked = false

  if type(text) == "table" then
    invoked = true

    if text.args then
      local frame = text

      local params = {
         = { required = true },
         = { required = true },
         = { required = true, allow_empty = true },
      }

      local args = m_params.process(frame.args, params)

      text = args
      pattern = args
      replacement = args
    else
      error("If the first argument to plain_gsub is a table, it should be a frame object.")
    end
  else
    if not (type(pattern) == "string" or type(pattern) == "number") then
      error("The second argument to plain_gsub should be a string or a number.")
    end

    if not (type(replacement) == "string" or type(replacement) == "number") then
      error("The third argument to plain_gsub should be a string or a number.")
    end
  end

  pattern = str.pattern_escape(pattern)

  if invoked then
    text = mw.ustring.gsub(text, pattern, replacement)
    return text
  else
    return mw.ustring.gsub(text, pattern, replacement)
  end
end

function str.matchToArray(text, pattern)
  local invoked = false

  if type(text) == "table" then
    invoked = true

    if text.args then
      local frame = text

      local params = {
         = { required = false },
         = { required = true },
      }

      local args = m_params.process(frame.args, params)

      text = args
      pattern = args
    else
      error("If the first argument to plain_gsub is a table, it should be a frame object.")
    end
  else
    if not (type(pattern) == "string" or type(pattern) == "number") then
      error("The second argument to plain_gsub should be a string or a number.")
    end
  end

  local matches = {}
  local i = 0
  for match in mw.ustring.gmatch(text, pattern) do
    i = i + 1
    matches = match
  end

  if i > 0 then
    if invoked then
      return table.concat(matches, ", ")
    else
      return matches
    end
  else
    if invoked then
      return ""
    else
      return nil
    end
  end
end

--[=[
	Similar to gmatch, but it returns the count of the match in addition to the
	list of captures, something like ipairs().
	
	If the pattern doesn't contain any captures, the whole match is returned.
	
	Invoke thus:
	
		for i, whole_match in require("Module:string").imatch(text, pattern) do
			
		end
	
	or
	
		for i, capture1]] in require("Module:string").imatch(text, pattern) do
			
		end
	
	For example, this code
		for i, whole_match in require("Module:string").imatch("a b c", "") do
			mw.log(i, whole_match)
		end
	will log
		1	a
		2	b
		3	c
]=]
function str.imatch(text, pattern, pos, plain, use_basic_Lua_function)
  local i = 0
  pos = pos or 0
  if not string.find(pattern, "%b()") then
    pattern = "(" .. pattern .. ")"
  end
  local find = use_basic_Lua_function and string.find or mw.ustring.find
  return function()
    i = i + 1
    local return_values = { find(text, pattern, pos, plain) }
    local j = return_values

    if return_values then
      pos = j + 1
      -- Skip the first two returned values, which are the indices of the
      -- whole match.
      return i, unpack(return_values, 3)
    end
  end
end

function str.escapebytes(s)
  return (string.gsub(s,
      '.',
      function(char)
        return ('\\%03d'):format(string.byte(char))
      end))
end

function str.URIdecode(frame)
  return mw.uri.decode(frame.args, frame.args or "PATH")
end

return str