Editing Module:Naval Vessel Register URL

--[[  
 
This module generates links to ships in the Naval Vessel Register (nvr.navy.mil) database.  
It is used by Template:Naval Vessel Register URL and Template:Naval Vessel Register service craft URL
 
Please do not modify this code without applying the changes first at Module:Naval Vessel Register URL/sandbox and testing 
at Module:Naval Vessel Register URL/sandbox/testcases and Module talk:Naval Vessel Register URL/sandbox/testcases.
 
Authors and maintainers:
* User:RP88
 
]]

require('strict')
local p = {}

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

local ships_data = {};
local srv_craft_data = {};

local data = mw.loadData ('Module:Naval Vessel Register URL/data');
	ships_data = data.nvr_ships_id;
	srv_craft_data = data.nvr_srv_craft_id;


--[[--------------------------< M A K E _ E R R O R _ M E S S A G E >------------------------------------------

General purpose error message function to render error messages and categorization

]]

local function make_error_message (output, prefix, item, suffix, srv_craft)
	local category = '';														-- for concatenation
	
	if 0 == mw.title.getCurrentTitle().namespace then							-- article namespace
		category = '[[Category:WPSHIPS:Template_errors]]';						-- categorize only from article namespace
	end
	
	table.insert (output, '<span style="font-size:100%" class="error">')
	table.insert (output, prefix);
	table.insert (output, item);
	table.insert (output, suffix);
	if srv_craft then
		table.insert (output, ' ([[Template:Naval Vessel Register service craft URL#Error messages|help]])</span>');
	else
		table.insert (output, ' ([[Template:Naval Vessel Register url#Error messages|help]])</span>');
	end
	table.insert (output, category);
	return
end


--[[--------------------------< M A K E _ S H I P _ L I N K >--------------------------------------------------

This function returns a link to a ship in the Naval Vessel Register.
 
Usage:
{{#invoke:Naval Vessel Register URL|MakeShipLink|1=|title=}}
{{#invoke:Naval Vessel Register URL|MakeShipLink}} - uses the caller's parameters
 
Parameters
    1, id: The ship's hull classification symbol
    2, title: A title or label for the link.
]]

function p.MakeShipLink (frame)
	local args = frame.args														-- if no argument provided, check parent template/module args
	local output = {};

	if (args[1]==nil) and (args["id"]==nil) then
		args = frame:getParent().args;
		if (args[1]==nil) and (args["id"]==nil) then
			make_error_message (output, 'required parameter missing', '', '');
			return table.concat (output);
		end
	end
	
	local hull = args["id"] or args[1] or '';
	local hull_designator;														-- for use with |name= parameter rendering
	local hull_prefix;
	local title = args["title"] or args[2] or '';
	
	if '' == title then															-- to prevent external links that look like this: [1]
		title = nil;
	end
	
	hull = mw.text.trim (hull):upper();											-- make sure that there is no leading/trailing whitespace and uppercase
																				-- standardize so that we can recognize as many formats as possible
	hull_designator = hull:match ('^T%-') or '';								-- if there is a 'T-' prefix to the prefix, save a copy of it; empty string for concatenation else
--error (hull_designator)
	hull = hull:gsub ('^T%-', '');												-- if hull classification symbol is T-XX-NNN, remove the 'T-'
	hull = hull:gsub ('(%a+)_(%d+)_%d+', '%1-%2');								-- if template has 'new' url identifier format (SSBN_659_1635); as of March 2019 this form not used at NVR
	hull = hull:gsub ('(%a+)[_ ]?(%d+)', '%1-%2');								-- if template has SSBN 659 or SSBN_659 or SSBN659 format
	hull_designator = hull_designator .. hull;									-- copy for use with |name= parameter

	if hull:match ('(%a+)%-%d+') then											-- most common case
		hull_prefix = hull:match ('(%a+)[%-_]?%d+');
	elseif hull:match ('[%a+ %(%)]+%-%d+') then									-- special one-off case for AFSB (I)-15
		hull_prefix = hull:match ('([%a+ %(%)]+)%-%d+')
	elseif hull:match ('^CONSTITUTION$') or hull:match ('^MAINE$') or hull:match ('^TEXAS$') then	-- Constitution, Maine, and Texas
		hull_prefix = hull;														-- do not have hull classification symbols; use their names
	else
		make_error_message (output, 'malformed hull classification symbol: ', hull, '');
		return table.concat (output);
	end
	
	if not ships_data[hull_prefix] then											-- is there a group for the hull number?
		make_error_message (output, 'unable to find group: [\'', hull_prefix, '\'] in [[Module:Naval Vessel Register URL/data]] nvr_ships_id');
		return table.concat (output);
	end

	if not ships_data[hull_prefix][hull] then									-- is there a hull number
		make_error_message (output, 'unable to find hull classification symbol: [\'', hull, '\'] in [[Module:Naval Vessel Register URL/data]] nvr_ships_id');
		return table.concat (output);
	end

	local nvr_id = ships_data[hull_prefix][hull][1];							-- try to fetch nvr id
	if not title and (args['name'] and '' ~= args['name']) then
		title = ships_data[hull_prefix][hull][2];
		if not title or '' == title then
			title = nil;														-- ensure
		elseif 'no name' == title:lower() then									-- new construction capital ships, and many service craft
			title = title .. ' (' .. hull_designator .. ')';
		elseif 'nh' == args['name'] then										-- special keyword to render name and hull designator
			title = '\'\'' .. ships_data[hull_prefix][hull][2] .. '\'\' (' .. hull_designator .. ')';
		else
			title = '\'\'' .. ships_data[hull_prefix][hull][2] .. '\'\'';		-- just the name
		end
	end

	if (nil ~= nvr_id) and ('' ~= nvr_id) then									-- there appears to be an identifier, so use it
		if title then															-- if there is a title then make an external link from it
			table.insert (output, '[');											-- opening bracket
		end
		table.insert (output, 'http://www.nvr.navy.mil/SHIPDETAILS/SHIPSDETAIL_');	-- create the url
		table.insert (output, nvr_id);
		table.insert (output, '.HTML');
		if title then
			table.insert (output, ' ');											-- required space
			table.insert (output, title);										-- title
			table.insert (output, ']');											-- and closing bracket
		end
		
	else																		-- no identifier
		make_error_message (output, 'no identifier for hull classification symbol: [\'', hull, '\'] in [[Module:Naval Vessel Register URL/data]] nvr_ships_id');
	end
	
	return table.concat (output);												-- and done
end


--[[--------------------------< M A K E _ S E R V I C E _ C R A F T _ L I N K >--------------------------------

This function returns a link to a service craft in the Naval Vessel Register.
 
Usage:
{{#invoke:Naval Vessel Register URL|MakeServiceCraftLink|1=|title=}}
{{#invoke:Naval Vessel Register URL|MakeServiceCraftLink}} - uses the caller's parameters
 
Parameters
    1, id: The 'file name' portion of the url path (typically the craft's hull designation) without the .HTM/.HTML extension. 
    2, title: A title or label for the link.
]]

function p.MakeServiceCraftLink( frame )
	-- if no argument provided than check parent template/module args
	local args = frame.args
	local output = {};

	if (args[1]==nil) and (args["id"]==nil) then
		args = frame:getParent().args;
		if (args[1]==nil) and (args["id"]==nil) then
			make_error_message (output, 'required parameter missing', '', '', true);
			return table.concat (output);
		end
	end
	
	local hull = args["id"] or args[1] or '';
	local hull_prefix;
	local title = args["title"] or args[2] or '';
	
	if '' == title then															-- to prevent external links that look like this: [1]
		title = nil;
	end
	
	hull = mw.text.trim (hull):upper();											-- make sure that there is no leading/trailing whitespace and uppercase
																				-- standardize so that we can recognize as many formats as possible
	hull = hull:gsub ('(%a+)_(%d+)_%d+', '%1-%2');								-- if template has 'new' url identifier format (YT_807_4629)
	hull = hull:gsub ('(%a+)[_ ]?(%d+)', '%1-%2');								-- if template has YT 807 or YT_807 or YT807 format

	if hull:match ('(%a+)%-%d+') then											-- most common case
		hull_prefix = hull:match ('(%a+)%-%d+');
	elseif hull:match ('(%a+)%-%d+%a') then										-- special cases for the various sections of floating dry docks;
		hull_prefix = hull:match ('(%a+)%-%d+%a');								-- each section has a single letter designator: AFDB-7F
	else
		make_error_message (output, 'malformed hull classification symbol: ', hull, '', true);
		return table.concat (output);
	end
	
	if not srv_craft_data[hull_prefix] then										-- is there a group for the hull number?
		make_error_message (output, 'unable to find group: [\'', hull_prefix, '\'] in [[Module:Naval Vessel Register URL/data]] nvr_srv_craft_id', true);
		return table.concat (output);
	end

	if not srv_craft_data[hull_prefix][hull] then								-- is there a hull number
		make_error_message (output, 'unable to find hull classification symbol: [\'', hull, '\'] in [[Module:Naval Vessel Register URL/data]] nvr_srv_craft_id', true);
		return table.concat (output);
	end

	local nvr_id = srv_craft_data[hull_prefix][hull][1];						-- try to fetch nvr id

	if (nil ~= nvr_id) and ('' ~= nvr_id) then									-- there appears to be an identifier, so use it
		if title then
			table.insert (output, '[');
		end
		table.insert (output, 'http://www.nvr.navy.mil/SHIPDETAILS/SHIPSDETAIL_');
		table.insert (output, nvr_id);
		table.insert (output, '.HTML');
		if title then
			table.insert (output, ' ');
			table.insert (output, title);
			table.insert (output, ']');
		end
	else																		-- no identifier
		make_error_message (output, 'no identifier for hull classification symbol: [\'', hull, '\'] in [[Module:Naval Vessel Register URL/data]] nvr_srv_craft_id', true);
	end
	
	return table.concat (output);
end

return p