--[[
This module is intended to replace the functionality of ((Coord)) and related
templates.  It provides several methods, including

((#invoke:Coordinates | coord )) : General function formatting and displaying
coordinate values.

((#invoke:Coordinates | dec2dms )) : Simple function for converting decimal
degree values to DMS format.

((#invoke:Coordinates | dms2dec )) : Simple function for converting DMS format
to decimal degree format.

((#invoke:Coordinates | link )) : Export the link used to reach the tools

]]

require('strict')

local math_mod = require("Module:Math")
local coordinates = {};
local isSandbox = mw.getCurrentFrame():getTitle():find('sandbox', 1, true);

local current_page = mw.title.getCurrentTitle()
local page_name = mw.uri.encode( current_page.prefixedText, 'WIKI' );
local coord_link = 'https://geohack.toolforge.org/geohack.php?pagename=' .. page_name .. '&params='

--[[ Helper function, replacement for ((coord/display/title)) ]]
local function displaytitle(coords)
	return mw.getCurrentFrame():extensionTag{
		name = 'indicator',
		args = { name = 'coordinates' },
		content = '<span id="coordinates">[[Geographic coordinate system|Coordinates]]: ' .. coords .. '</span>'
	}
end

--[[ Helper function, used in detecting DMS formatting ]]
local function dmsTest(first, second)
	if type(first) ~= 'string' or type(second) ~= 'string' then
		return nil
	end
	local s = (first .. second):upper()
	return s:find('^[NS][EW]$') or s:find('^[EW][NS]$')
end


--[[ Wrapper function to grab args, see Module:Arguments for this function's documentation. ]]
local function makeInvokeFunc(funcName)
	return function (frame)
		local args = require('Module:Arguments').getArgs(frame, {
			wrappers = 'Template:Coord'
		})
		return coordinates[funcName](args, frame)
	end
end

--[[ Helper function, handle optional args. ]]
local function optionalArg(arg, supplement)
	return arg and arg .. supplement or ''
end

--[[
Formats any error messages generated for display
]]
local function errorPrinter(errors)
	local result = ""
	for i,v in ipairs(errors) do
		result = result .. '<strong class="error">Coordinates: ' .. v[2] .. '</strong><br />'
	end
	return result
end

--[[
Determine the required CSS class to display coordinates

Usually geo-nondefault is hidden by CSS, unless a user has overridden this for himself
default is the mode as specificied by the user when calling the ((coord)) template
mode is the display mode (dec or dms) that we will need to determine the css class for
]]
local function displayDefault(default, mode)
	if default == "" then
		default = "dec"
	end

	if default == mode then
		return "geo-default"
	else
		return "geo-nondefault"
	end
end

--[[
specPrinter

Output formatter.  Takes the structure generated by either parseDec
or parseDMS and formats it for inclusion on Wikipedia.
]]
local function specPrinter(args, coordinateSpec)
	local uriComponents = coordinateSpec["param"]
	if uriComponents == "" then
		-- RETURN error, should never be empty or nil
		return "ERROR param was empty"
	end
	if args["name"] then
		uriComponents = uriComponents .. "&title=" .. mw.uri.encode(coordinateSpec["name"])
	end

	local geodmshtml = '<span class="geo-dms" title="Maps, aerial photos, and other data for this location">'
			.. '<span class="latitude">' .. coordinateSpec["dms-lat"] .. '</span> '
			.. '<span class="longitude">' ..coordinateSpec["dms-long"] .. '</span>'
			.. '</span>'

	local lat = tonumber( coordinateSpec["dec-lat"] ) or 0
	local geodeclat
	if lat < 0 then
		-- FIXME this breaks the pre-existing precision
		geodeclat = tostring(coordinateSpec["dec-lat"]):sub(2) .. "°S"
	else
		geodeclat = (coordinateSpec["dec-lat"] or 0) .. "°N"
	end

	local long = tonumber( coordinateSpec["dec-long"] ) or 0
	local geodeclong
	if long < 0 then
		-- FIXME does not handle unicode minus
		geodeclong = tostring(coordinateSpec["dec-long"]):sub(2) .. "°W"
	else
		geodeclong = (coordinateSpec["dec-long"] or 0) .. "°E"
	end

	local geodechtml = '<span class="geo-dec" title="Maps, aerial photos, and other data for this location">'
			.. geodeclat .. ' '
			.. geodeclong
			.. '</span>'

	local geonumhtml = '<span class="geo">'
			.. coordinateSpec["dec-lat"] .. '; '
			.. coordinateSpec["dec-long"]
			.. '</span>'

	local inner = '<span class="' .. displayDefault(coordinateSpec["default"], "dms" ) .. '">' .. geodmshtml .. '</span>'
				.. '<span class="geo-multi-punct">&#xfeff; / &#xfeff;</span>'
				.. '<span class="' .. displayDefault(coordinateSpec["default"], "dec" ) .. '">';

	if not args["name"] then
		inner = inner .. geodechtml
				.. '<span style="display:none">&#xfeff; / ' .. geonumhtml .. '</span></span>'
	else
		inner = inner .. '<span class="vcard">' .. geodechtml
				.. '<span style="display:none">&#xfeff; / ' .. geonumhtml .. '</span>'
				.. '<span style="display:none">&#xfeff; (<span class="fn org">'
				.. args["name"] .. '</span>)</span></span></span>'
	end

    local stylesheetLink = 'Module:Coordinates' .. ( isSandbox and '/sandbox' or '' ) .. '/styles.css'
	return mw.getCurrentFrame():extensionTag{
		name = 'templatestyles', args = { src = stylesheetLink }
	} .. '<span class="plainlinks nourlexpansion load-gadget" data-gadget="WikiMiniAtlas">[' .. coord_link .. uriComponents ..
	' ' .. inner .. ']</span>'
end

--[[ Helper function, convert decimal to degrees ]]
local function convert_dec2dms_d(coordinate)
	local d = math_mod._round( coordinate, 0 ) .. "°"
	return d .. ""
end

--[[ Helper function, convert decimal to degrees and minutes ]]
local function convert_dec2dms_dm(coordinate)
	coordinate = math_mod._round( coordinate * 60, 0 );
	local m = coordinate % 60;
	coordinate = math.floor( (coordinate - m) / 60 );
	local d = coordinate % 360 .."°"

	return d .. string.format( "%02d′", m )
end

--[[ Helper function, convert decimal to degrees, minutes, and seconds ]]
local function convert_dec2dms_dms(coordinate)
	coordinate = math_mod._round( coordinate * 60 * 60, 0 );
	local s = coordinate % 60
	coordinate = math.floor( (coordinate - s) / 60 );
	local m = coordinate % 60
	coordinate = math.floor( (coordinate - m) / 60 );
	local d = coordinate % 360 .."°"

	return d .. string.format( "%02d′", m ) .. string.format( "%02d″", s )
end

--[[
Helper function, convert decimal latitude or longitude to
degrees, minutes, and seconds format based on the specified precision.
]]
local function convert_dec2dms(coordinate, firstPostfix, secondPostfix, precision)
	local coord = tonumber(coordinate)
	local postfix
	if coord >= 0 then
		postfix = firstPostfix
	else
		postfix = secondPostfix
	end

	precision = precision:lower();
	if precision == "dms" then
		return convert_dec2dms_dms( math.abs( coord ) ) .. postfix;
	elseif precision == "dm" then
		return convert_dec2dms_dm( math.abs( coord ) ) .. postfix;
	elseif precision == "d" then
		return convert_dec2dms_d( math.abs( coord ) ) .. postfix;
	end
end

--[[
Convert DMS format into a N or E decimal coordinate
]]
local function convert_dms2dec(direction, degrees_str, minutes_str, seconds_str)
	local degrees = tonumber(degrees_str)
	local minutes = tonumber(minutes_str) or 0
	local seconds = tonumber(seconds_str) or 0

	local factor = 1
	if direction == "S" or direction == "W" then
		factor = -1
	end

	local precision = 0
	if seconds_str then
		precision = 5 + math.max( math_mod._precision(seconds_str), 0 );
	elseif minutes_str and minutes_str ~= '' then
		precision = 3 + math.max( math_mod._precision(minutes_str), 0 );
	else
		precision = math.max( math_mod._precision(degrees_str), 0 );
	end

	local decimal = factor * (degrees+(minutes+seconds/60)/60)
	return string.format( "%." .. precision .. "f", decimal ) -- not tonumber since this whole thing is string based.
end

--[[
Checks input values to for out of range errors.
]]
local function validate( lat_d, lat_m, lat_s, long_d, long_m, long_s, source, strong )
	local errors = {};
	lat_d = tonumber( lat_d ) or 0;
	lat_m = tonumber( lat_m ) or 0;
	lat_s = tonumber( lat_s ) or 0;
	long_d = tonumber( long_d ) or 0;
	long_m = tonumber( long_m ) or 0;
	long_s = tonumber( long_s ) or 0;

	if strong then
		if lat_d < 0 then
			table.insert(errors, {source, "latitude degrees < 0 with hemisphere flag"})
		end
		if long_d < 0 then
			table.insert(errors, {source, "longitude degrees < 0 with hemisphere flag"})
		end
		--[[
		#coordinates is inconsistent about whether this is an error.  If globe: is
		specified, it won't error on this condition, but otherwise it will.

		For not simply disable this check.

		if long_d > 180 then
			table.insert(errors, {source, "longitude degrees > 180 with hemisphere flag"})
		end
		]]
	end

	if lat_d > 90 then
		table.insert(errors, {source, "latitude degrees > 90"})
	end
	if lat_d < -90 then
		table.insert(errors, {source, "latitude degrees < -90"})
	end
	if lat_m >= 60 then
		table.insert(errors, {source, "latitude minutes >= 60"})
	end
	if lat_m < 0 then
		table.insert(errors, {source, "latitude minutes < 0"})
	end
	if lat_s >= 60 then
		table.insert(errors, {source, "latitude seconds >= 60"})
	end
	if lat_s < 0 then
		table.insert(errors, {source, "latitude seconds < 0"})
	end
	if long_d >= 360 then
		table.insert(errors, {source, "longitude degrees >= 360"})
	end
	if long_d <= -360 then
		table.insert(errors, {source, "longitude degrees <= -360"})
	end
	if long_m >= 60 then
		table.insert(errors, {source, "longitude minutes >= 60"})
	end
	if long_m < 0 then
		table.insert(errors, {source, "longitude minutes < 0"})
	end
	if long_s >= 60 then
		table.insert(errors, {source, "longitude seconds >= 60"})
	end
	if long_s < 0 then
		table.insert(errors, {source, "longitude seconds < 0"})
	end

	return errors;
end

--[[
parseDec

Transforms decimal format latitude and longitude into the
structure to be used in displaying coordinates
]]
local function parseDec( lat, long, format )
	local coordinateSpec = {}
	local errors = {}

	if not long then
		return nil, (("parseDec", "Missing longitude"))
	elseif not tonumber(long) then
		return nil, (("parseDec", "Longitude could not be parsed as a number: " .. long))
	end

	errors = validate( lat, nil, nil, long, nil, nil, 'parseDec', false );
	coordinateSpec["dec-lat"]  = lat;
	coordinateSpec["dec-long"] = long;

	local mode = coordinates.determineMode( lat, long );
	coordinateSpec["dms-lat"]  = convert_dec2dms( lat, "N", "S", mode)  -- ((coord/dec2dms|(({1))}|N|S|((coord/prec dec|(({1))}|(({2))))))}
	coordinateSpec["dms-long"] = convert_dec2dms( long, "E", "W", mode)  -- ((coord/dec2dms|(({2))}|E|W|((coord/prec dec|(({1))}|(({2))))))}

	if format then
		coordinateSpec.default = format
	else
		coordinateSpec.default = "dec"
	end

	return coordinateSpec, errors
end

--[[
parseDMS

Transforms degrees, minutes, seconds format latitude and longitude
into the a structure to be used in displaying coordinates
]]
local function parseDMS( lat_d, lat_m, lat_s, lat_f, long_d, long_m, long_s, long_f, format )
	local coordinateSpec, errors, backward = {}, {}

	lat_f = lat_f:upper();
	long_f = long_f:upper();

	-- Check if specified backward
	if lat_f == 'E' or lat_f == 'W' then
		lat_d, long_d, lat_m, long_m, lat_s, long_s, lat_f, long_f, backward = long_d, lat_d, long_m, lat_m, long_s, lat_s, long_f, lat_f, true;
	end

	errors = validate( lat_d, lat_m, lat_s, long_d, long_m, long_s, 'parseDMS', true );
	if not long_d then
		return nil, (("parseDMS", "Missing longitude" ))
	elseif not tonumber(long_d) then
		return nil, (("parseDMS", "Longitude could not be parsed as a number:" .. long_d ))
	end

	if not lat_m and not lat_s and not long_m and not long_s and #errors == 0 then
		if math_mod._precision( lat_d ) > 0 or math_mod._precision( long_d ) > 0 then
			if lat_f:upper() == 'S' then
				lat_d = '-' .. lat_d;
			end
			if long_f:upper() == 'W' then
				long_d = '-' .. long_d;
			end

			return parseDec( lat_d, long_d, format );
		end
	end

	coordinateSpec["dms-lat"]  = lat_d.."°"..optionalArg(lat_m,"′") .. optionalArg(lat_s,"″") .. lat_f
	coordinateSpec["dms-long"] = long_d.."°"..optionalArg(long_m,"′") .. optionalArg(long_s,"″") .. long_f
	coordinateSpec["dec-lat"]  = convert_dms2dec(lat_f, lat_d, lat_m, lat_s) -- ((coord/dms2dec|(({4))}|(({1))}|0(({2))}|0(({3))))}
	coordinateSpec["dec-long"] = convert_dms2dec(long_f, long_d, long_m, long_s) -- ((coord/dms2dec|(({8))}|(({5))}|0(({6))}|0(({7))))}

	if format then
		coordinateSpec.default = format
	else
		coordinateSpec.default = "dms"
	end

	return coordinateSpec, errors, backward
end

--[[
Check the input arguments for coord to determine the kind of data being provided
and then make the necessary processing.
]]
local function formatTest(args)
	local result, errors
	local backward, primary = false, false

	local function getParam(args, lim)
		local ret = {}
		for i = 1, lim do
			ret[i] = args[i] or ''
		end
		return table.concat(ret, '_')
	end

	if not args[1] then
		-- no lat logic
		return errorPrinter( (("formatTest", "Missing latitude")) )
	elseif not tonumber(args[1]) then
		-- bad lat logic
		return errorPrinter( (("formatTest", "Unable to parse latitude as a number:" .. args[1])) )
	elseif not args[4] and not args[5] and not args[6] then
		-- dec logic
		result, errors = parseDec(args[1], args[2], args.format)
		if not result then
			return errorPrinter(errors);
		end
		-- formatting for geohack: geohack expects D_N_D_E notation or D;D notation
		-- wikiminiatlas doesn't support D;D notation
		-- #coordinates parserfunction doesn't support negative decimals with NSWE
		result.param = table.concat({
			math.abs(tonumber(args[1])),
			((tonumber(args[1]) or 0) < 0) and 'S' or 'N',
			math.abs(tonumber(args[2])),
			((tonumber(args[2]) or 0) < 0) and 'W' or 'E',
			args[3] or ''}, '_')
	elseif dmsTest(args[4], args[8]) then
		-- dms logic
		result, errors, backward = parseDMS(args[1], args[2], args[3], args[4],
			args[5], args[6], args[7], args[8], args.format)
		if args[10] then
			table.insert(errors, {'formatTest', 'Extra unexpected parameters'})
		end
		if not result then
			return errorPrinter(errors)
		end
		result.param = getParam(args, 9)
	elseif dmsTest(args[3], args[6]) then
		-- dm logic
		result, errors, backward = parseDMS(args[1], args[2], nil, args[3],
			args[4], args[5], nil, args[6], args['format'])
		if args[8] then
			table.insert(errors, {'formatTest', 'Extra unexpected parameters'})
		end
		if not result then
			return errorPrinter(errors)
		end
		result.param = getParam(args, 7)
	elseif dmsTest(args[2], args[4]) then
		-- d logic
		result, errors, backward = parseDMS(args[1], nil, nil, args[2],
			args[3], nil, nil, args[4], args.format)
		if args[6] then
			table.insert(errors, {'formatTest', 'Extra unexpected parameters'})
		end
		if not result then
			return errorPrinter(errors)
		end
		result.param = getParam(args, 5)
	else
		-- Error
		return errorPrinter((("formatTest", "Unknown argument format"))) .. '[[Category:Pages with malformed coordinate tags]]'
	end
	result.name = args.name

	local extra_param = {'dim', 'globe', 'scale', 'region', 'source', 'type'}
	for _, v in ipairs(extra_param) do
		if args[v] then
			table.insert(errors, {'formatTest', 'Parameter: "' .. v .. '=" should be "' .. v .. ':"' })
		end
	end

	local ret = specPrinter(args, result)
	if #errors > 0 then
		ret = ret .. ' ' .. errorPrinter(errors) .. '[[Category:Pages with malformed coordinate tags]]'
	end
	return ret, backward
end

--[[
Generate Wikidata tracking categories.
]]
local function makeWikidataCategories(qid)
	local ret
	local qid = qid or mw.wikibase.getEntityIdForCurrentPage()
	if mw.wikibase and current_page.namespace == 0 then
		if qid and mw.wikibase.entityExists(qid) and mw.wikibase.getBestStatements(qid, "P625") and mw.wikibase.getBestStatements(qid, "P625")[1] then
			local snaktype = mw.wikibase.getBestStatements(qid, "P625")[1].mainsnak.snaktype
			if snaktype == 'value' then
				-- coordinates exist both here and on Wikidata, and can be compared.
				ret = 'Coordinates on Wikidata'
			elseif snaktype == 'somevalue' then
				ret = 'Coordinates on Wikidata set to unknown value'
			elseif snaktype == 'novalue' then
				ret = 'Coordinates on Wikidata set to no value'
			end
		else
			-- We have to either import the coordinates to Wikidata or remove them here.
			ret = 'Coordinates not on Wikidata'
		end
	end
	if ret then
		return string.format('[[Category:%s]]', ret)
	else
		return ''
	end
end

--[[
link

Simple function to export the coordinates link for other uses.

Usage:
	((#invoke:Coordinates | link ))

]]
function coordinates.link(frame)
	return coord_link;
end

--[[
dec2dms

Wrapper to allow templates to call dec2dms directly.

Usage:
	((#invoke:Coordinates | dec2dms | decimal_coordinate | positive_suffix |
		negative_suffix | precision ))

decimal_coordinate is converted to DMS format.  If positive, the positive_suffix
is appended (typical N or E), if negative, the negative suffix is appended.  The
specified precision is one of 'D', 'DM', or 'DMS' to specify the level of detail
to use.
]]
coordinates.dec2dms = makeInvokeFunc('_dec2dms')
function coordinates._dec2dms(args)
	local coordinate = args[1]
	local firstPostfix = args[2] or ''
	local secondPostfix = args[3] or ''
	local precision = args[4] or ''

	return convert_dec2dms(coordinate, firstPostfix, secondPostfix, precision)
end

--[[
Helper function to determine whether to use D, DM, or DMS
format depending on the precision of the decimal input.
]]
function coordinates.determineMode( value1, value2 )
	local precision = math.max( math_mod._precision( value1 ), math_mod._precision( value2 ) );
	if precision <= 0 then
		return 'd'
	elseif precision <= 2 then
		return 'dm';
	else
		return 'dms';
	end
end

--[[
dms2dec

Wrapper to allow templates to call dms2dec directly.

Usage:
	((#invoke:Coordinates | dms2dec | direction_flag | degrees |
		minutes | seconds ))

Converts DMS values specified as degrees, minutes, seconds too decimal format.
direction_flag is one of N, S, E, W, and determines whether the output is
positive (i.e. N and E) or negative (i.e. S and W).
]]
coordinates.dms2dec = makeInvokeFunc('_dms2dec')
function coordinates._dms2dec(args)
	local direction = args[1]
	local degrees = args[2]
	local minutes = args[3]
	local seconds = args[4]

	return convert_dms2dec(direction, degrees, minutes, seconds)
end

--[[
coord

Main entry point for Lua function to replace ((coord))

Usage:
	((#invoke:Coordinates | coord ))
	((#invoke:Coordinates | coord | lat | long ))
	((#invoke:Coordinates | coord | lat | lat_flag | long | long_flag ))
	...

	Refer to ((coord)) documentation page for many additional parameters and
	configuration options.

Note: This function provides the visual display elements of ((coord)).  In
order to load coordinates into the database, the ((#coordinates:)) parser
function must also be called, this is done automatically in the Lua
version of ((coord)).
]]
coordinates.coord = makeInvokeFunc('_coord')
function coordinates._coord(args)
	if not tonumber(args[1]) and not args[2] then
		args[3] = args[1]; args[1] = nil
		local entity = mw.wikibase.getEntityObject(args.qid)
		if entity
			and entity.claims
			and entity.claims.P625
			and entity.claims.P625[1].mainsnak.snaktype == 'value'
		then
			local precision = entity.claims.P625[1].mainsnak.datavalue.value.precision
			args[1] = entity.claims.P625[1].mainsnak.datavalue.value.latitude
			args[2] = entity.claims.P625[1].mainsnak.datavalue.value.longitude
			if precision then
				precision = -math_mod._round(math.log(precision)/math.log(10),0)
				args[1] = math_mod._round(args[1],precision)
				args[2] = math_mod._round(args[2],precision)
			end
		end
	end

	local contents, backward = formatTest(args)
	local Notes = args.notes or ''
	local Display = args.display and args.display:lower() or 'inline'

	-- it and ti are short for inline,title and title,inline
	local function isInline(s)
		-- Finds whether coordinates are displayed inline.
		return s:find('inline') ~= nil or s == 'i' or s == 'it' or s == 'ti'
	end
	local function isInTitle(s)
		-- Finds whether coordinates are displayed in the title.
		return s:find('title') ~= nil or s == 't' or s == 'it' or s == 'ti'
	end

	local function coord_wrapper(in_args)
		-- Calls the parser function ((#coordinates:)).
		return mw.getCurrentFrame():callParserFunction('#coordinates', in_args) or ''
	end

	local text = ''
	if isInline(Display) then
		text = text .. '<span class="geo-inline">' .. contents .. Notes .. '</span>'
	end
	if isInTitle(Display) then
		-- Add to output since indicator content is invisible to Lua later on
		if not isInline(Display) then
			text = text .. '<span class="geo-inline-hidden noexcerpt">' .. contents .. Notes .. '</span>'
		end
		text = text .. displaytitle(contents .. Notes) .. makeWikidataCategories(args.qid)
	end
	if not args.nosave then
		local page_title, count = mw.title.getCurrentTitle(), 1
		if backward then
			local tmp = {}
			while not string.find((args[count-1] or ''), '[EW]') do tmp[count] = (args[count] or ''); count = count+1 end
			tmp.count = count; count = 2*(count-1)
			while count >= tmp.count do table.insert(tmp, 1, (args[count] or '')); count = count-1 end
			for i, v in ipairs(tmp) do args[i] = v end
		else
			while count <= 9 do args[count] = (args[count] or ''); count = count+1 end
		end
		if isInTitle(Display) and not page_title.isTalkPage and page_title.subpageText ~= 'doc' and page_title.subpageText ~= 'testcases' then args[10] = 'primary' end
		args.notes, args.format, args.display = nil
		text = text .. coord_wrapper(args)
	end
	return text
end

--[[
coord2text

Extracts a single value from a transclusion of ((Coord)).
IF THE GEOHACK LINK SYNTAX CHANGES THIS FUNCTION MUST BE MODIFIED.

Usage:

    ((#invoke:Coordinates | coord2text | ((Coord)) | parameter ))

Valid values for the second parameter are: lat (signed integer), long (signed integer), type, scale, dim, region, globe, source

]]
function coordinates._coord2text(coord,type)
	if coord == '' or type == '' or not type then return nil end
	type = mw.text.trim(type)
	if type == 'lat' or type == 'long' then
		local result, negative = mw.text.split((mw.ustring.match(coord,'[%.%d]+°[NS] [%.%d]+°[EW]') or ''), ' ')
		if type == 'lat' then
			result, negative = result[1], 'S'
		else
			result, negative = result[2], 'W'
		end
		result = mw.text.split(result, '°')
		if result[2] == negative then result[1] = '-'..result[1] end
		return result[1]
	else
		return mw.ustring.match(coord, 'params=.-_' .. type .. ':(.-)[ _]')
	end
end

function coordinates.coord2text(frame)
	return coordinates._coord2text(frame.args[1],frame.args[2])
end

--[[
coordinsert

Injects some text into the Geohack link of a transclusion of ((Coord)) (if that text isn't already in the transclusion). Outputs the modified transclusion of ((Coord)).
IF THE GEOHACK LINK SYNTAX CHANGES THIS FUNCTION MUST BE MODIFIED.

Usage:

    ((#invoke:Coordinates | coordinsert | ((Coord)) | parameter:value | parameter:value | … ))

Do not make Geohack unhappy by inserting something which isn't mentioned in the ((Coord)) documentation.

]]
function coordinates.coordinsert(frame)
	-- for the 2nd or later integer parameter (the first is the coord template, as above)
	for i, v in ipairs(frame.args) do
		if i ~= 1 then
			-- if we cannot find in the coord_template the i_th coordinsert parameter e.g. region
			if not mw.ustring.find(frame.args[1], (mw.ustring.match(frame.args[i], '^(.-:)') or '')) then
				-- find from the params= up to the first possibly-present underscore
				-- and append the i_th coordinsert parameter and a space
				-- IDK why we're adding a space but it does seem somewhat convenient
				frame.args[1] = mw.ustring.gsub(frame.args[1], '(params=.-)_? ', '%1_'..frame.args[i]..' ')
			end
		end
	end
	if frame.args.name then
		-- if we can't find the vcard class
		if not mw.ustring.find(frame.args[1], '<span class="vcard">') then
			-- take something that looks like a coord template and add the vcard span with class and fn org class
			local namestr = frame.args.name
			frame.args[1] = mw.ustring.gsub(
				frame.args[1],
				'(<span class="geo%-default">)(<span[^<>]*>[^<>]*</span><span[^<>]*>[^<>]*<span[^<>]*>[^<>]*</span></span>)(</span>)',
				'%1<span class="vcard">%2<span style="display:none">&#xfeff; (<span class="fn org">' .. namestr .. '</span>)</span></span>%3'
			)
			-- then find anything from coordinates parameters to the 'end' and attach the title parameter
			frame.args[1] = mw.ustring.gsub(
				frame.args[1],
				'(&params=[^&"<>%[%] ]*) ',
				'%1&title=' .. mw.uri.encode(namestr) .. ' '
			)
		end
	end
	
	-- replace the existing indicator with a new indicator using the modified content
	frame.args[1] = mw.ustring.gsub(
		frame.args[1],
		'(<span class="geo%-inline[^"]*">(.+)</span>)\127[^\127]*UNIQ%-%-indicator%-%x+%-%-?QINU[^\127]*\127',
		function (inline, coord) return inline .. displaytitle(coord) end
	)

	return frame.args[1]
end

return coordinates