Modul:Citation/CS1/Utilities

local u = {}

local z = {
    error_categories = {};                                                        -- for categorizing citations that contain errors
    error_ids = {};
    message_tail = {};
    maintenance_cats = {};                                                        -- for categorizing citations that aren't erroneous per se, but could use a little work
    properties_cats = {};                                                        -- for categorizing citations based on certain properties, language of source for instance
};


--[[--------------------------< F O R W A R D   D E C L A R A T I O N S >--------------------------------------
]]

local cfg;                                                                        -- table of tables imported from slected Module:Citation/CS1/Configuration


--[[--------------------------< I S _ S E T >------------------------------------------------------------------

Returns true if argument is set; false otherwise. Argument is 'set' when it exists (not nil) or when it is not an empty string.
This function is global because it is called from both this module and from Date validation

]]
local function is_set( var )
    return not (var == nil or var == '');
end


--[[--------------------------< I N _ A R R A Y >--------------------------------------------------------------

Whether needle is in haystack

]]

local function in_array( needle, haystack )
    if needle == nil then
        return false;
    end
    for n,v in ipairs( haystack ) do
        if v == needle then
            return n;
        end
    end
    return false;
end


--[[--------------------------< S U B S T I T U T E >----------------------------------------------------------

Populates numbered arguments in a message string using an argument table.

]]

local function substitute( msg, args )
    return args and mw.message.newRawMessage( msg, args ):plain() or msg;
end


--[[--------------------------< E R R O R _ C O M M E N T >----------------------------------------------------

Wraps error messages with css markup according to the state of hidden.

]]
local function error_comment( content, hidden )
    return substitute( hidden and cfg.presentation['hidden-error'] or cfg.presentation['visible-error'], content );
end


--[[--------------------------< S E T _ E R R O R >--------------------------------------------------------------

Sets an error condition and returns the appropriate error message.  The actual placement of the error message in the output is
the responsibility of the calling function.

]]
local function set_error( error_id, arguments, raw, prefix, suffix )
    local error_state = cfg.error_conditions[ error_id ];
    
    prefix = prefix or "";
    suffix = suffix or "";
    
    if error_state == nil then
        error( cfg.messages['undefined_error'] );
    elseif is_set( error_state.category ) then
        table.insert( z.error_categories, error_state.category );
    end
    
    local message = substitute( error_state.message, arguments );
    
    message = message .. " ([[" .. cfg.messages['help page link'] ..
        "#" .. error_state.anchor .. "|" ..
        cfg.messages['help page label'] .. "]])";
    
    z.error_ids[ error_id ] = true;
    if in_array( error_id, { 'bare_url_missing_title', 'trans_missing_title' } )
            and z.error_ids['citation_missing_title'] then
        return '', false;
    end
    
    message = table.concat({ prefix, message, suffix });
    
    if raw == true then
        return message, error_state.hidden;
    end        
        
    return error_comment( message, error_state.hidden );
end


--[[-------------------------< I S _ A L I A S _ U S E D >-----------------------------------------------------

This function is used by select_one() to determine if one of a list of alias parameters is in the argument list
provided by the template.

Input:
    args – pointer to the arguments table from calling template
    alias – one of the list of possible aliases in the aliases lists from Module:Citation/CS1/Configuration
    index – for enumerated parameters, identifies which one
    enumerated – true/false flag used choose how enumerated aliases are examined
    value – value associated with an alias that has previously been selected; nil if not yet selected
    selected – the alias that has previously been selected; nil if not yet selected
    error_list – list of aliases that are duplicates of the alias already selected

Returns:
    value – value associated with alias we selected or that was previously selected or nil if an alias not yet selected
    selected – the alias we selected or the alias that was previously selected or nil if an alias not yet selected

]]

local function is_alias_used (args, alias, index, enumerated, value, selected, error_list)
    if enumerated then                                                            -- is this a test for an enumerated parameters?
        alias = alias:gsub ('#', index);                                        -- replace '#' with the value in index
    else
        alias = alias:gsub ('#', '');                                            -- remove '#' if it exists
    end

    if is_set(args[alias]) then                                                    -- alias is in the template's argument list
        if value ~= nil and selected ~= alias then                                -- if we have already selected one of the aliases
            local skip;
            for _, v in ipairs(error_list) do                                    -- spin through the error list to see if we've added this alias
                if v == alias then
                    skip = true;
                    break;                                                        -- has been added so stop looking
                end
            end
            if not skip then                                                    -- has not been added so
                table.insert( error_list, alias );                                -- add error alias to the error list
            end
        else
            value = args[alias];                                                -- not yet selected an alias, so select this one
            selected = alias;
        end
    end
    return value, selected;                                                        -- return newly selected alias, or previously selected alias
end


--[[--------------------------< A D D _ M A I N T _ C A T >------------------------------------------------------

Adds a category to z.maintenance_cats using names from the configuration file with additional text if any.
To prevent duplication, the added_maint_cats table lists the categories by key that have been added to z.maintenance_cats.

]]

local added_maint_cats = {}                                                        -- list of maintenance categories that have been added to z.maintenance_cats
local function add_maint_cat (key, arguments)
    if not added_maint_cats [key] then
        added_maint_cats [key] = true;                                            -- note that we've added this category
        table.insert( z.maintenance_cats, substitute (cfg.maint_cats [key], arguments));    -- make name then add to table
    end
end


--[[--------------------------< S A F E _ F O R _ I T A L I C S >----------------------------------------------

Protects a string that will be wrapped in wiki italic markup '' ... ''

Note: We cannot use <i> for italics, as the expected behavior for italics specified by ''...'' in the title is that
they will be inverted (i.e. unitalicized) in the resulting references.  In addition, <i> and '' tend to interact
poorly under Mediawiki's HTML tidy.

]]

local function safe_for_italics( str )
    if not is_set(str) then
        return str;
    else
        if str:sub(1,1) == "'" then str = "<span></span>" .. str; end
        if str:sub(-1,-1) == "'" then str = str .. "<span></span>"; end
        
        -- Remove newlines as they break italics.
        return str:gsub( '\n', ' ' );
    end
end


--[[--------------------------< W R A P _ S T Y L E >----------------------------------------------------------

Applies styling to various parameters.  Supplied string is wrapped using a message_list configuration taking one
argument; protects italic styled parameters.  Additional text taken from citation_config.presentation - the reason
this function is similar to but separate from wrap_msg().

]]

local function wrap_style (key, str)
    if not is_set( str ) then
        return "";
    elseif in_array( key, { 'italic-title', 'trans-italic-title' } ) then
        str = safe_for_italics( str );
    end

    return substitute( cfg.presentation[key], {str} );
end


--[[--------------------------< S E L E C T _ O N E >----------------------------------------------------------

Chooses one matching parameter from a list of parameters to consider.  The list of parameters to consider is just
names.  For parameters that may be enumerated, the position of the numerator in the parameter name is identified
by the '#' so |author-last1= and |author1-last= are represented as 'author-last#' and 'author#-last'.

Because enumerated parameter |<param>1= is an alias of |<param>= we must test for both possibilities.


Generates an error if more than one match is present.

]]

local function select_one( args, aliases_list, error_condition, index )
    local value = nil;                                                            -- the value assigned to the selected parameter
    local selected = '';                                                        -- the name of the parameter we have chosen
    local error_list = {};

    if index ~= nil then index = tostring(index); end

    for _, alias in ipairs( aliases_list ) do                                    -- for each alias in the aliases list
        if alias:match ('#') then                                                -- if this alias can be enumerated
            if '1' == index then                                                -- when index is 1 test for enumerated and non-enumerated aliases
                value, selected = is_alias_used (args, alias, index, false, value, selected, error_list);    -- first test for non-enumerated alias
            end
            value, selected = is_alias_used (args, alias, index, true, value, selected, error_list);        -- test for enumerated alias
        else
            value, selected = is_alias_used (args, alias, index, false, value, selected, error_list);        --test for non-enumerated alias
        end
    end

    if #error_list > 0 and 'none' ~= error_condition then                        -- for cases where this code is used outside of extract_names()
        local error_str = "";
        for _, k in ipairs( error_list ) do
            if error_str ~= "" then error_str = error_str .. cfg.messages['parameter-separator'] end
            error_str = error_str .. wrap_style ('parameter', k);
        end
        if #error_list > 1 then
            error_str = error_str .. cfg.messages['parameter-final-separator'];
        else
            error_str = error_str .. cfg.messages['parameter-pair-separator'];
        end
        error_str = error_str .. wrap_style ('parameter', selected);
        table.insert( z.message_tail, { set_error( error_condition, {error_str}, true ) } );
    end
    
    return value, selected;
end


--[=[-------------------------< R E M O V E _ W I K I _ L I N K >----------------------------------------------

Gets the display text from a wikilink like [[A|B]] or [[B]] gives B

]=]

local function remove_wiki_link (str)
    return (str:gsub( "%[%[([^%[%]]*)%]%]", function(l)
        return l:gsub( "^[^|]*|(.*)$", "%1" ):gsub("^%s*(.-)%s*$", "%1");
    end));
end


--[[--------------------------< S E T _ S E L E C T E D _ M O D U L E S >--------------------------------------

Sets local cfg table to same (live or sandbox) as that used by the other modules.

]]

local function set_selected_modules (cfg_table_ptr)
    cfg = cfg_table_ptr;
end



return {                                                                        -- return exported functions and tables
    is_set = is_set,
    in_array = in_array,
    substitute = substitute,
    error_comment = error_comment,
    set_error = set_error,
    select_one = select_one,
    add_maint_cat = add_maint_cat,
    wrap_style = wrap_style;
    safe_for_italics = safe_for_italics;
    remove_wiki_link = remove_wiki_link;
    set_selected_modules = set_selected_modules;
    z = z,
    }