Editing Module:Infobox television/sandbox

require("strict")

--- @module
local p = {}

-- local maintenance_categories = {
-- 	non_matching_title = "[[Category:Pages using infobox television with non-matching title]]",
-- 	unnecessary_title_parameter = "[[Category:Pages using infobox television with unnecessary name parameter]]",
-- 	unlinked_values = "[[Category:Pages using infobox television with unlinked values|%s]]",
-- 	temp = "[[Category:Temp infobox television tracking category|%s]]",
-- }

local maintenance_categories = {
	-- alt_name = {
	-- 	category = "[[Category:Pages using infobox television with incorrectly formatted values|%s]]",
	-- 	warning = "",
	-- },
	dates_incorrectly_formatted = {
		category = "[[Category:Pages using infobox television with nonstandard dates]]",
		warning = {
			future_dates = "the infobox does not support dates set in the future. Remove the date and only add a date once the program has aired.",
			start_date = "start dates should use the {{tl|Start date}} template.",
			end_date = "end dates should use the {{tl|End date}} template.",
			multiple_dates = "do not use multiple date parameters in the same parameter. Each date should be placed in its own parameter.",
		}
	},
	dates_missing = {
		category = "[[Category:Pages using infobox television with missing dates]]",
		warning = {
			start_date = "a |first_aired= date is missing.",
			end_date = "a |last_aired= date is missing.",
		}
	},
	flag_icon = {
		category = "[[Category:Pages using infobox television with flag icon]]",
		warning = "flag icons should not be used per [[MOS:INFOBOXFLAG]].",
	},
	image_values_without_an_image = {
		category = "[[Category:Pages using infobox television with image-related values without an image]]",
		warning = "an image is not used in the infobox. Remove value from |%s=.",
	},
	incorrectly_formatted = {
		category = "[[Category:Pages using infobox television with incorrectly formatted values|%s]]",
		warning = {
			country_name = "country name should not be an abbreviation.",
			based_on = "use the title of the original work in the |based_on= value.",
			duplicate = "duplicate parameter usage found. Only one of %s can be used.",
			external_links = "external links should not be used in infobox. Remove link from |%s=.",
			inccorct_credit_usage = "a credit in |%s= uses %s. %s has its own parameter, please use it.",
			inccorct_credit_usage_based_on = "a credit in |%s= uses %s. Use the |based_on= parameter instead.",
			invalid_credit = "%s is not a valid credit for |%s=.",
			italic_title = "remove value from |italic_title=.",
			language = "langauge should not be linked per [[WP:OVERLINK]].",
			multiple_networks = "for shows with multiple networks or release gaps, use the additional release date parameters.",
			num_episodes = "|num_episodes= should only be a number value.",
		}
	},
	manual_display_title = {
		category = "[[Category:Pages using infobox television with unnecessary manual displaytitle]]",
		warning = "remove %s as the infobox handles this automatically.",
	},
	manual_display_title_temp_tracking = {
		category = "[[Category:Pages using infobox television with manual displaytitle]]",
		warning = "",
	},
	non_matching_title = {
		category = "[[Category:Pages using infobox television with non-matching title]]",
		warning = "",
	},
	unnecessary_title_parameter = {
		category = "[[Category:Pages using infobox television with unnecessary name parameter]]",
		warning = "",
	},
	unlinked_values = {
		category = "[[Category:Pages using infobox television with unlinked values|%s]]",
		warning = "",
	},
	temp = {
		category = "[[Category:Temp infobox television tracking category|%s]]",
		warning = "",
	},
}

local number_of_network_sets = 8

local error_prefix = "{{tl|Infobox television}} errors: "
local function add_warning(error_text)
	--TODO: ignore if on the testcases page?
	mw.addWarning(error_prefix .. error_text)
end

--- Returns a table consisting of the title's title parts.
---
--- The return table's properties:
--- - title - The title.
--- - disambiguation - the disambiguation text without parentheses.
---
--- Note: could potentially be moved to an outside module for other template and module uses.
---
--- @param text string
--- @return table<string, string | nil>
local function get_title_parts(text)
	local title, disambiguation = string.match(text, "^(.+) (%b())$")

	if not title or type(title) ~= "string" then
		title = text
	end

	---@type table<string, string | nil>
	local title_parts = {title = --[[---@not number | nil]] title, disambiguation = nil}

	if not disambiguation or type(disambiguation) ~= "string" then
		return title_parts
	end

	-- Remove outside parentheses from names which use parentheses as part of the name such as "episode (Randall and Hopkirk (Deceased))".
	disambiguation = string.sub(--[[---@not number | nil]] disambiguation, 2, -2)
	title_parts.disambiguation = --[[---@not number]] disambiguation
	return title_parts
end

--- Returns a maintenance category if the italic_title value is not "no".
---
--- Infobox parameters checked:
--- - |italic_title=
---
--- @param args table
--- @return string
local function is_italic_title_valid_value(args)
	if args.italic_title and args.italic_title ~= "no" then
		add_warning(maintenance_categories.incorrectly_formatted.warning.italic_title)
		return string.format(maintenance_categories.incorrectly_formatted.category, "italic_title")
	end
	return ""
end

--TODO: add doc
local function is_value_a_url(args)
	for key, value in pairs(args) do
		if string.find(value, "http") then
			add_warning(string.format(maintenance_categories.incorrectly_formatted.warning.external_links, key))
			return string.format(maintenance_categories.incorrectly_formatted.category, key)
		end
	end
	return ""
end

--- Returns a maintenance category if the start_date value is set to a future date.
---
--- Infobox parameters checked:
--- - |first_aired[1-number_of_network_sets]=
--- - |released[1-number_of_network_sets]=
---
--- @param args table
--- @return string
local function is_start_date_in_the_future(start_date)
	-- Extract the date from the start_date.
	local date_pattern = ".*<span[^>]*>(.-)</span>"
	local extracted_date = start_date:match(date_pattern)

	-- Parse the date components
	local year, month, day = extracted_date:match("(%d+)-(%d+)-(%d+)")

	-- Create a table with the parsed date components
	local date_table = {
	    year = tonumber(year) or 0,
	    month = tonumber(month) or 0,
	    day = tonumber(day) or 0,
	    hour = 0,	-- Assuming 00:00:00 for simplicity
	    min = 0,
	    sec = 0
	}

	-- Convert the date table to a Unix timestamp
	local start_date_timestamp = os.time(date_table)

	-- Get the current date components.
	local current_date = os.date("*t")

	-- Set the time components to zero.
	current_date.hour = 0
	current_date.min = 0
	current_date.sec = 0

	-- Convert the date components into a timestamp.
	local current_timestamp = os.time(current_date)

	--local extracted_date_timestamp = os.time(extracted_date)

	-- The infobox does not allow for future dates.
	if current_timestamp < start_date_timestamp then
		add_warning(maintenance_categories.dates_incorrectly_formatted.warning.future_dates)
		return maintenance_categories.dates_incorrectly_formatted.category
	end
	
	return ""
end

--- Returns a maintenance category if the dates are not formatted correctly with
--- {{Start date}} and {{End date}} templates.
---
--- Infobox parameters checked:
--- - |first_aired[1-number_of_network_sets]=
--- - |released[1-number_of_network_sets]=
--- - |last_aired[1-number_of_network_sets]=
---
--- Note: all_tests is meant only for /testcases testing.
---
--- @param all_tests string Testing conditional value.
--- @param released string The start date value.
--- @param first_aired string The start date value.
--- @param last_aired string The end date value.
--- @return string
local function are_dates_formatted_correctly(all_tests, released, first_aired, last_aired)
	-- To keep /testcases clean, this is set so only what is test is shown.
	if all_tests == "no" then
		return ""
	end
	
	-- Config parameters
	local first_aired_future = "Upcoming"
	local last_aired_current = "present"
	local start_date_class = "itvstart"
	local end_date_class = "itvend"
	local film_date_class = "film%-date"

	local start_date = released or first_aired

	-- A start date should always be set.
	if not start_date then
		add_warning(maintenance_categories.dates_missing.warning.start_date)
		return maintenance_categories.dates_missing.category
	end

	-- Validate the start date is formmated using {{Start date}} and not any other template, including {{Film date}}, or uses the word "Upcoming".
	if start_date and (string.find(start_date, film_date_class) or not string.find(start_date, start_date_class) and start_date ~= first_aired_future) then
		add_warning(maintenance_categories.dates_incorrectly_formatted.warning.start_date)
		return maintenance_categories.dates_incorrectly_formatted.category
	end

	-- An end date should always be set if the show or film wasn't released all at once.
	if first_aired and first_aired ~= first_aired_future and not last_aired then
		add_warning(maintenance_categories.dates_missing.warning.end_date)
		return maintenance_categories.dates_missing.category
	end

	-- Validate the end date is formmated using {{End date}} and not any other template, or uses the word "present".
	if last_aired and (not string.find(last_aired, end_date_class) and last_aired ~= last_aired_current) then
		add_warning(maintenance_categories.dates_incorrectly_formatted.warning.end_date)
		return maintenance_categories.dates_incorrectly_formatted.category
	end

	-- Only one date should be used per field.
	if (start_date and select(2, string.gsub(start_date, start_date_class, "")) > 1) or (last_aired and select(2, string.gsub(last_aired, end_date_class, "")) > 1) then
		add_warning(maintenance_categories.dates_incorrectly_formatted.warning.multiple_dates)
		return maintenance_categories.dates_incorrectly_formatted.category
	end
	
	-- Check if start date is set to a future date.
	if start_date ~= first_aired_future then
		return is_start_date_in_the_future(start_date)
	end
	
	return ""
end

--- Returns a maintenance category if exclusive parameter sets are used.
---
--- Infobox parameters checked:
--- - |image_alt= and |alt=
--- - |image_size= and |image_upright= 
--- - |based_on= and |inspired_by=
--- - |screenplay= and |teleplay=
--- - |presenter= and |host= 
--- - |narrator=, |narrated= and |announcer=
--- - |theme_music_composer= and |music=
--- - |open_theme= and |opentheme=
--- - |end_theme= and |endtheme=
--- - |released[1-number_of_network_sets]= and |first_aired[1-number_of_network_sets]=
--- - |released[1-number_of_network_sets]= and |last_aired[1-number_of_network_sets]=
--- - |network[1-number_of_network_sets]= and |channel[1-number_of_network_sets]=
---
--- The function currently checks if the network and channel parameters both have values.
---
--- @param args table
--- @param args table
--- @return string
local function _are_exclusive_parameter_sets_used(args, parameters)
	for key, set in pairs(parameters) do
		if args[set[1]] and args[set[2]] then
			add_warning(string.format(maintenance_categories.incorrectly_formatted.warning.duplicate, key))
			return string.format(maintenance_categories.incorrectly_formatted.category, "-duplicate")
		end
	end

	return ""
end

--- Returns a maintenance category if exclusive parameter sets are used.
--- Create a set parameters to check.
--- Does not include release information related parameters which are sent from
--- a different function due to their numbered variations.
--- See _are_exclusive_parameter_sets_used() for more details.
---
--- @param args table
--- @return string
local function are_exclusive_parameter_sets_used(args)
	local parameters = {
		["|image_alt= and |alt="] = {"image_alt", "alt"},
		["|image_size= and |image_upright="] = {"image_size", "image_upright"},
		["|based_on= and |inspired_by="] = {"based_on", "inspired_by"},
		["|screenplay= and |teleplay="] = {"screenplay", "teleplay"},
		["|presenter= and |host="] = {"presenter", "host"},
		["|narrator= and |narrated="] = {"narrator", "narrated"},
		["|narrator= and |announcer="] = {"narrator", "announcer"},
		["|narrated= and |announcer="] = {"narrated", "announcer"},
		["|theme_music_composer= and |music="] = {"theme_music_composer", "music"},
		["|open_theme= and |opentheme="] = {"open_theme", "opentheme"},
		["|end_theme= and |endtheme="] = {"end_theme", "endtheme"},
	}

	return _are_exclusive_parameter_sets_used(args, parameters)
end

--- Returns a maintenance category if the values are unlinked.
---
--- Infobox parameters checked:
--- - |network[1-number_of_network_sets]=
--- - |channel[1-number_of_network_sets]=
---
--- The function currently checks if a value is unlinked.
---
--- @param args table
--- @return string
local function are_values_unlinked(args)
	for key, value in pairs(args) do
		-- Check whether the values are linked.
		if value and not string.find(value, "%[%[.*%]%]") then
			return string.format(maintenance_categories.unlinked_values.category, key)
		end
	end

	return ""
end

--- Returns a maintenance category if the dates are not formatted correctly
--- and using "Original", "Revival" or italics to denote a split in the date range.
---
--- Infobox parameters checked:
--- - |first_aired[1-number_of_network_sets]=
--- - |released[1-number_of_network_sets]=
--- - |last_aired[1-number_of_network_sets]=
--- - |network[1-number_of_network_sets]=
--- - |channel[1-number_of_network_sets]=
---
--- @param args table
--- @return string
local function does_release_information_have_extraneous_text(args)
	for k, v in pairs(args) do
		if string.find(string.lower(v), "original") and not string.find(string.lower(v), "aboriginal")	or 
			string.find(string.lower(v), "revival") or 
			string.find(v, "''") then
			add_warning(maintenance_categories.incorrectly_formatted.warning.multiple_networks)
			return string.format(maintenance_categories.incorrectly_formatted.category, k)
		end
	end
	return ""
end

--- Returns a maintenance category if the release information:
---- Is not formatted correctly
---- Has extraneous text
---- Dates don't use correct mark up
---
--- Infobox parameters checked:
--- - |first_aired[1-number_of_network_sets]=
--- - |released[1-number_of_network_sets]=
--- - |last_aired[1-number_of_network_sets]=
--- - |network[1-number_of_network_sets]=
--- - |channel[1-number_of_network_sets]=
---
--- @param args table
--- @return string
local function is_release_information_formatted_correctly(args)
	local release_information = {"first_aired", "released", "last_aired", "network", "channel"}
	local categories = {}
		
	for i = 1, number_of_network_sets do
		local num = ""
		if i > 1 then
			num = i
		end

		local numbered_args = {}
		for _, v in pairs(release_information) do
			numbered_args[v .. num] = args[v .. num]
		end

		-- If current table is empty, break current cycle.	
		if next(numbered_args) then
			table.insert(categories, does_release_information_have_extraneous_text(numbered_args))
			table.insert(categories, are_values_unlinked({network = args["network" .. num], channel = args["channel" .. num]}))
			local duplicates = {
				["|network" .. num .. "= and |channel" .. num .. "="] = {"network" .. num, "channel" .. num},
				["|released" .. num .. "= and |first_aired" .. num .. "="] = {"released" .. num, "first_aired" .. num},
				["|released" .. num .. "= and |last_aired" .. num .. "="] = {"released" .. num, "last_aired" .. num},
			}
			table.insert(categories, _are_exclusive_parameter_sets_used(args, duplicates))
			table.insert(categories, are_dates_formatted_correctly(args.all_tests, args["released" .. num], args["first_aired" .. num], args["last_aired" .. num]))
		end
	end

	return categories
end

--- Returns a maintenance category if a {{Italic title}} or {{DISPLAYTITLE}} template is used.
--- Checks also for the following {{Italic title}} redirects:
---- Italic
---- Italics
---- Italictitle
---- Italics title
---
--- Testing parameters:
--- - |page_test= - a real Wikipedia page to read the content of the page.
---
--- Infobox parameters checked:
--- - |italic_title=
---
--- @param args table
--- @return string
local function has_display_title(args)
	--TODO: when testing below is done uncomment code
	--if args.italic_title then
	--	return ""
	--end

	local article
	if args.page_test then
		article = mw.title.new(args.page_test)
	else
		article = mw.title.getCurrentTitle()
	end

	local page_text = article:getContent()
	if not page_text then
		return ""
	end

	if (string.find(page_text, "{{[Ii]talics?%s?title}}") or string.find(page_text, "{{[Ii]talics?}}")) and not string.match(page_text, "{{[Ii]talic title|all=yes}}") then
		add_warning(string.format(maintenance_categories.manual_display_title.warning, "{{tl|Italic title}}"))
		return maintenance_categories.manual_display_title.category
	end

	local display_title = string.match(page_text, "{{DISPLAYTITLE:(.*)}}")
	if display_title then
		local article_title = article.text
		if article_title == display_title or article_title == string.sub(display_title, 3, string.len(display_title) - 2) then
			add_warning(string.format(maintenance_categories.manual_display_title.warning, "DISPLAYTITLE"))
			return maintenance_categories.manual_display_title.category
		elseif string.find(display_title, "<sub>") or string.find(display_title, "<sup>") then
			-- TODO: This is valid. Will remove when done with cleanup.
			return ""
		else
			-- TODO: remove when done checking results.
			--add_warning(maintenance_categories.manual_display_title_temp_tracking.warning)
			return maintenance_categories.manual_display_title_temp_tracking.category
		end
	end

	return ""
end

--- Returns a maintenance category if a flag icon is used.
---
--- All the infobox values are checked.
---
--- @param args table
--- @return string
local function has_flag_icon(args)
	for _, v in pairs(args) do
		if string.find(v, "flagicon") then
			add_warning(maintenance_categories.flag_icon.warning)
			return maintenance_categories.flag_icon.category
		end
	end
	return ""
end

--- Returns a maintenance category if num_episodes uses:
--- - "as of" as text
--- - A date template
---
--- Infobox parameters checked:
--- - |num_episodes=
---
--- @param num_episodes string
--- @return string
local function does_num_episodes_have_extraneous_text(num_episodes)
	if not num_episodes then
		return ""
	end

	if string.find(string.lower(num_episodes), "as of")
	or string.find(num_episodes, "dtstart") then
		add_warning(maintenance_categories.incorrectly_formatted.warning.num_episodes)
		return	string.format(maintenance_categories.incorrectly_formatted.category, "num_episodes")
	end
	
	return ""
end

--- Returns a maintenance category if |based_on uses a generic word instead
--- of the title of the original work:
--- "book"
--- "novel"
---
--- Infobox parameters checked:
--- - |based_on=
---
--- @param num_episodes string
--- @return string
local function is_based_on_used_correctly(based_on)
	if not based_on then
		return ""
	end

	local generic_titles = {
		"book",
		"novel",
	}

	-- Remove content enclosed by double single quotes (''text'')
	local stripped_text = based_on:gsub("''[^']*''", "")
    -- Remove content enclosed by double quotes ("text")
    stripped_text = based_on:gsub('"[^"]*"', "")
	-- Remove content enclosed by double square brackets ([[text]])
	stripped_text = based_on:gsub("%[%[.-%]%]", "")

	-- Convert to lowercase to ensure case-insensitive matching
	stripped_text = stripped_text:lower()

	for _, word in pairs(generic_titles) do
		if string.find(stripped_text, word) then
			add_warning(maintenance_categories.incorrectly_formatted.warning.based_on)
			return string.format(maintenance_categories.incorrectly_formatted.category, "based_on")
		end
	end

	return ""
end

--- Checks if a string is in the exceptions list.
--- 
--- @param str string
--- @return boolean
local function is_in_credit_exceptions(str)
	local exceptions = {
		"Aulsondro \"Novelist\" Hamilton",
		-- Booker can be a last name.
		"Booker",
		"Jack Trevor Story",
		"Tanveer Bookwala",
		"Sanford Bookstaver",
	}

    for _, exception in ipairs(exceptions) do
        if string.find(str, exception) then
            return true
        end
    end
    return false
end

--- Returns a maintenance category if a credit information matches a pattern.
---
--- @param key string
--- @param value string
--- @param invalid_credits table
--- @return string
local function check_credits(key, value, invalid_credits)
	for _, invalid_credit in pairs(invalid_credits) do
		local pattern = "%f[%a]" .. invalid_credit
		if string.find(string.lower(value), pattern) and not is_in_credit_exceptions(value) then
			return string.format(maintenance_categories.incorrectly_formatted.category, key), invalid_credit
		end
	end
end

--- Returns a maintenance category if "lyric" or "dialogue" are found.
--- This is a temporary function to check how widespread this unsupported usage is.
---
--- @param parameter string
--- @param text string
--- @return string
local function is_credit_used_correctly_tracking_credits(parameter, text)
	local credits = {
		"lyric",
		"dialogue",
	}

	local category, invalid_credit = check_credits(parameter, text, credits)
	if category then
		return string.format(maintenance_categories.temp.category, invalid_credit)
	end

	return ""
end

--- Returns a maintenance category if a writing credit is used incorrectly.
---
--- @param parameter string
--- @param text string
--- @return string
local function is_credit_used_correctly_incorrectly_placed_credits(parameter, text)
	local credits = {
		"book",
		"manuscript",
		"novel",
		"script",
		"screenplay",
		"story",
		"teleplay",
	}

	local based_on = {
	    book = true,
	    manuscript = true,
	    novel = true,
	}

	local category, invalid_credit = check_credits(parameter, text, credits)
	if category then
		local invalid_credit_clean = string.gsub(invalid_credit, "%%", "")

		local valid_parameter
		if based_on[invalid_credit_clean] then
			valid_parameter = "|based_on="
			add_warning(string.format(maintenance_categories.incorrectly_formatted.warning.inccorct_credit_usage_based_on, parameter, invalid_credit_clean, valid_parameter))
		else
			valid_parameter = "|" .. invalid_credit_clean .. "="
			add_warning(string.format(maintenance_categories.incorrectly_formatted.warning.inccorct_credit_usage, parameter, invalid_credit_clean, valid_parameter))
		end

		return category
	end

	return ""
end

--- Returns a maintenance category if an unusupported credit is used.
---
--- @param parameter string
--- @param text string
--- @return string
local function is_credit_used_correctly_invalid_credits(parameter, text)
	local credits = {
		"assistant",
		"associate",
		"co%-",
		"executive",
		"line producer",
		"on%-line",
		"prod%.",
		"supervising",
	}

	local category, invalid_credit = check_credits(parameter, text, credits)
	if category then
		local invalid_credit_clean = "'''" .. string.gsub(invalid_credit, "%%", "") .. "'''"
		add_warning(string.format(maintenance_categories.incorrectly_formatted.warning.invalid_credit, invalid_credit_clean, parameter))
		return category
	end

	return ""
end

--- Returns a maintenance category if a credit information entered is from the following list:
--- "assistant", associate", "co-", "executive", "line producer", "on-line", "prod%.", "supervising"
--- "book", "manuscript", "novel", "script", "screenplay", "story", "teleplay"
--- TODO: "lyric" and "dialogue" should be either supported or removed.
--- These credits have their own unique parameters that should be used instead.
---
--- Infobox parameters checked:
--- - |director=
--- - |editor=
--- - |executive_producer=
--- - |producer=
--- - |screenplay=
--- - |story=
--- - |teleplay=
--- - |writer=
---
--- @param args table
--- @return string
local function is_credit_used_correctly(args)
	local credits_list = {
		"director",
		"editor",
		"executive_producer",
		"producer",
		"screenplay",
		"story",
		"teleplay",
		"writer",
	}
	
	local credits = {}
	for _, value in pairs(credits_list) do
	    credits[value] = args[value]
	end

	local tracking_credits = {
		"lyric", -- temp
		"dialogue", -- temp
	}
	
	local delink = require("Module:Delink")._delink
	for parameter, text in pairs(credits) do
		text = delink{text}
		
		local category = is_credit_used_correctly_invalid_credits(parameter, text)
		category = category .. is_credit_used_correctly_incorrectly_placed_credits(parameter, text)
		category = category .. is_credit_used_correctly_tracking_credits(parameter, text)
		return category
	end

	return ""
end



--- Returns a maintenance category if the country information entered is from the following list:
--- U.S.A, USA, U.S., US, UK, U.K.
---
--- Infobox parameters checked:
--- - |country=
---
--- @param country string
--- @return string
local function is_country_name_valid(country)
	if not country then
		return ""
	end

	local args = {"U.S", "US", "UK", "U.K."}
	for _, v in pairs(args) do
		if string.find(country, v) then
			add_warning(maintenance_categories.incorrectly_formatted.warning.country_name)
			return string.format(maintenance_categories.incorrectly_formatted.category, "country")
		end
	end
	return ""
end

--- Returns a maintenance category if the language is linked.
---
--- Infobox parameters checked:
--- - |language=
---
--- The function currently checks if the following values are present:
--- - ] - links.
---
--- @param args table
--- @return string
local function is_language_linked(args)
	local parameters = {language = args.language}
	for key, value in pairs(parameters) do
		for _, bad_value in pairs({"]"}) do
			if string.find(value, bad_value, 1, true) then
				add_warning(maintenance_categories.incorrectly_formatted.warning.language)
				return string.format(maintenance_categories.incorrectly_formatted.category, key)
			end
		end
	end
	return ""
end

-- Splits a string and returns a table.
--
-- @param str string
-- @return table
local function split(str)
	local sep = "\n"
	local result = {}
	local regex = ("([^%s]+)"):format(sep)
	for each in str:gmatch(regex) do
		table.insert(result, each)
	end
	return result
end

-- Returns a string value clean from various list syntax.
--
-- @param str string
-- @return string
local function clean_list_syntax(str)
	str = string.gsub(str, "\127[^\127]*UNIQ%-%-(%a+)%-%x+%-QINU[^\127]*\127", "")				-- Remove all strip-markers.
	str = string.gsub(string.gsub(str, "%<%/? *div[^%>]*%>", ""), "%<%/? *span[^%>]*%>", "")	-- Removes div and span tags.
	str = string.gsub(str, "%<%/? *ul[^%>]*%>", "")		-- Remove list tags.
	str = string.gsub(str, "%<%/? *li[^%>]*%>", "\n")	-- Remove list tags. Replace with new line.
	str = string.gsub(str, "</? *br */?>", "\n")		-- Replace <br /> (and variants) with new line.
	str = string.gsub(str, "\n\n", "\n")				-- Replace double new line with a single new line.
	str = string.gsub(str, "*", "")						-- Remove asterisks.
	return str
end

--- Returns a maintenance category if the |image= value includes the "File:"
--- or "Image:" prefix, or if it is a URL.
---
--- Infobox parameters checked:
--- - |image=
---
--- @param image string
--- @return string
local function is_image_using_incorrect_syntax(image)
	if not image then
		return ""
	end

	local invalid_strings = {
		"file:",
		"image:",
	}

	image = string.lower(image)
	for _, invalid in ipairs(invalid_strings) do
		if string.find(image, invalid) then
			return string.format(maintenance_categories.incorrectly_formatted.category, "image")
		end
	end

	return ""
end

--- Returns a maintenance category if the |image_size= value includes "px".
---
--- Infobox parameters checked:
--- - |image_size=
---
--- @param image_size string
--- @return string
local function is_image_size_using_px(image_size)
	if image_size and string.find(image_size, "px") then
		return string.format(maintenance_categories.incorrectly_formatted.category, "image_size")
	end
	return ""
end

--- Returns a maintenance category if there is no image file while image auxiliary values are present.
---
--- Infobox parameters checked:
--- - |image=
--- - |image_size=
--- - |image_upright=
--- - |image_alt=
--- - |alt=
--- - |caption=
---
--- @param args table
--- @return string
local function are_image_auxiliary_values_used_for_no_image(args)
	if args.image then
		return ""
	end

	local image_args = {
		image_size = args.image_size,
		image_upright = args.image_upright,
		image_alt = args.image_alt,
		alt = args.alt,
		caption = args.caption
	}

	for key, value in pairs(image_args) do
		if value then
			add_warning(string.format(maintenance_categories.image_values_without_an_image.warning, key))
			return maintenance_categories.image_values_without_an_image.category
		end
	end

	return ""
end

--- Returns the display title text used in either the {{DISPLAYTITLE}} or {{Italic title}} templates.
---
--- @param page_text string
--- @param article_title string
--- @return string | nil
local function get_display_title_text(page_text, article_title)
	if not page_text then
		return nil
	end

	local title_modification = string.match(page_text, "{{DISPLAYTITLE:(.-)}}")
	if title_modification and type(title_modification) == "string" then
		local title_parts = get_title_parts(title_modification)
		return string.gsub(title_parts.title, "'", "")
	end

	title_modification = string.match(page_text, "{{[Ii]talic title|all=yes}}")
	if title_modification and type(title_modification) == "string" then
		return article_title
	end

	return nil
end

--- Returns the title used in the {{Lowercase title}} template and an optional maintenance category.
---
--- @param page_text string
--- @param args table
--- @param article_title string
--- @param title_parts table
--- @param return_category boolean
--- @return string | nil
local function get_lowercase_template_status(page_text, args, article_title, title_parts, return_category)
	if not page_text then
		return nil
	end
	local lowercase_template =  string.match(page_text, "{{[Ll]owercase title.-}}")

	if not lowercase_template then
		return nil
	end

	local lowercase_title
	if string.find(lowercase_template, "|force=") then
		lowercase_title = string.gsub(article_title,"^%u", string.lower)
	else
		lowercase_title = string.gsub(title_parts.title,"^%u", string.lower)
	end

	if return_category and args.name then
		if args.name == lowercase_title then
			return maintenance_categories.unnecessary_title_parameter.category
		else
			return maintenance_categories.non_matching_title.category
		end
		return ""
	end

	return lowercase_title
end

--- Returns the title used in the {{Correct title}} template and an optional maintenance category.
---
--- @param page_text string
--- @param args table
--- @param return_category boolean
--- @return string | nil
local function get_correct_title_value(page_text, args, return_category)
	if not page_text then
		return nil
	end

	local correct_title_template_pattern = "{{[Cc]orrect title|title=(.*)|reason=.-}}"

	local correct_title = string.match(page_text, correct_title_template_pattern)

	if not correct_title then
		correct_title_template_pattern = "{{[Cc]orrect title|(.*)|reason=.-}}"
		correct_title = string.match(page_text, correct_title_template_pattern)
	end

	if not correct_title and type(correct_title) ~= "string" then
		return nil
	end

	local correct_title_title_parts = get_title_parts(correct_title)

	if return_category and args.name then
		if args.name == correct_title or args.name == correct_title_title_parts.title then
			return maintenance_categories.unnecessary_title_parameter.category
		else
			return maintenance_categories.non_matching_title.category
		end
	end

	return correct_title
end

--- Returns a maintenance category if the infobox title is equal to the article title.
---
--- Infobox parameters checked:
--- - |name=
---
--- The function currently checks if the infobox title is equal to the article title while ignoring styling such as:
--- - Nowrap spans.
--- - Line breaks.
---
--- A return value can be one of three options:
--- - The value of maintenance_categories.non_matching_title - when the args.title does not match the article title..category
--- - The value of maintenance_categories.unnecessary_title_parameter - when the args.title matches the article title..category
--- - An empty string - when args.name isn't used or the args.name uses an allowed modification
--- (such as a nowrap template) while the rest of the args.name matches the article title.
---
--- Testing parameters:
--- - |page_test= - a real Wikipedia page to read the content of the page.
--- - |page_title_test= - the title of the page being checked.
---
--- @param frame table
--- @param args table
--- @return string
local function is_infobox_title_equal_to_article_title(frame, args)
	if not args.name then
		return ""
	end

	local page_text
	if args.page_test then
		page_text = mw.title.new(args.page_test):getContent()
	else
		page_text = mw.title.getCurrentTitle():getContent()
	end

	-- Check if the article is using a {{Correct title}} template.
	local correct_title = get_correct_title_value(page_text, args, true)
	if correct_title then
		return correct_title
	end

	local article_title = args.page_title_test
	if not args.page_title_test then
		article_title = mw.title.getCurrentTitle().text
	end

	-- Remove disambiguation.
	local title_parts = get_title_parts(article_title)

	-- Check if the article is using a {{Lowercase title}} template.
	local lowercase_title = get_lowercase_template_status(page_text, args, article_title, title_parts, true)
	if lowercase_title then
		return lowercase_title
	end

	-- Remove nowrap span.
	if string.find(args.name, "nowrap") then
		local title = frame:expandTemplate{title = "Strip tags", args = {args.name}}
		if title == article_title or title == title_parts.title then
			return ""
		end
		return maintenance_categories.non_matching_title.category
	end

	-- Remove line breaks and additional spaces as a result.
	if string.find(args.name, "<br%s?/?>") then
		local title, _ = string.gsub(args.name, "<br%s?/?>", "")
		title, _ = string.gsub(title, "  ", " ")
		if title == article_title or title == title_parts.title then
			return ""
		end
		return maintenance_categories.non_matching_title.category
	end

	if args.name == article_title or args.name == title_parts.title then
		return maintenance_categories.unnecessary_title_parameter.category
	end

	-- Article and infobox titles do not match.
	return maintenance_categories.non_matching_title.category
end

--- Returns the relevant maintenance categories based on the {{Infobox television}} values validated.
---
--- @param frame table
--- @return string
function p.validate_values(frame)
	local getArgs = require("Module:Arguments").getArgs
	local args = getArgs(frame)

	local categories = {}
	table.insert(categories, is_infobox_title_equal_to_article_title(frame, args))
	table.insert(categories, has_display_title(args))
	table.insert(categories, are_image_auxiliary_values_used_for_no_image(args))
	table.insert(categories, is_image_using_incorrect_syntax(args.image))
	table.insert(categories, is_image_size_using_px(args.image_size))
	-- table.insert(categories, is_language_linked(args)) -- commenting out for now
	table.insert(categories, is_country_name_valid(args.country))
	table.insert(categories, has_flag_icon(args))
	table.insert(categories, is_credit_used_correctly(args))
	table.insert(categories, is_based_on_used_correctly(args.based_on))
	table.insert(categories, does_num_episodes_have_extraneous_text(args.num_episodes))
	table.insert(categories, are_exclusive_parameter_sets_used(args))
	table.insert(categories, is_value_a_url(args))
	local release_categories = is_release_information_formatted_correctly(args)
	
	for _, v in ipairs(release_categories) do
        table.insert(categories, v)
	end

	table.insert(categories, is_italic_title_valid_value(args))

	return table.concat(categories, "")
end

--- Returns the text used for the |above= field of the infobox.
---
--- Infobox parameters checked:
--- - |name=
---
--- Testing parameters:
--- - |page_test= - a real Wikipedia page to read the content of the page.
--- - |page_title_test= - the title of the page being checked.
---
--- @param frame table
--- @return string
function p.above_title(frame)
	local getArgs = require("Module:Arguments").getArgs
	local args = getArgs(frame)

	local page
	if args.page_test then
		page = mw.title.new(args.page_test)
	else
		page = mw.title.getCurrentTitle()
	end

	local page_text = page:getContent()

	local article_title = args.page_title_test
	if not args.page_title_test then
		article_title = page.text
	end

	local title_format = "''%s''"

	local correct_title = get_correct_title_value(page_text, args, false)
	if correct_title then
		return string.format(title_format, correct_title)
	end

	local title_parts = get_title_parts(article_title)

	local lowercase_title = get_lowercase_template_status(page_text, args, article_title, title_parts, false)
	if lowercase_title then
		return string.format(title_format, lowercase_title)
	end

	if args.italic_title then
		local title_modification = get_display_title_text(page_text, article_title)
		if title_modification then
			return string.format(title_format, title_modification)
		end
	end

	if args.name then
		return string.format(title_format, args.name)
	end

	return string.format(title_format, title_parts.title)
end

return p

--Commented out code. Might be used in the future.

--- Returns a maintenance category if the values are formatted.
---
--- Most of the infobox values are checked. Not included are:
--- - |caption=
--- - |alt_name=
--- - |native_name=
--- - |based_on=
--- - |inspired_by=
--- - |open_theme=
--- - |end_theme=
---
--- The function currently checks if the following values are present:
--- - '' - italics or bold.
---
--- @param args table
--- @return string
-- local function are_values_incorrect_formatted_with_bold_or_italics(args)
-- 	---@type table<string, boolean>
-- 	local ignore_parameters = {
-- 		caption = true,
-- 		alt_name = true,
-- 		native_name = true,
-- 		based_on = true,
-- 		inspired_by = true,
-- 		open_theme = true,
-- 		end_theme = true,
-- 	}

-- 	for key, value in pairs(args) do
-- 		if not ignore_parameters[key] and string.find(value, "''", 1, true) then
-- 			add_warning(maintenance_categories.incorrectly_formatted.warning."country name should not be an abbreviation")
-- 			return string.format(maintenance_categories.incorrectly_formatted.category, key)
-- 		end
-- 	end
-- 	return ""
-- end

--- Returns a maintenance category if:
---- When alt_name= is a list of values, and not all entries are in italics.
---- When alt_name= is a single value and is in italics.
----- This is because the template automatically handles the italics and when also manually added,
----- results in 4 apostrophes which produce a bold title instead.
---
--- Infobox parameters checked:
--- - |alt_name=
---
--- @param alt_name string
--- @return string
-- local function is_alt_name_in_italics(alt_name)
-- 	if not alt_name then
-- 		return ""
-- 	end
-- 	local detect_singular = require("Module:Detect singular")._main
-- 	local args = {alt_name, ["no_and"] = "1", ["no_comma"] = "1"}
-- 	local is_singular = detect_singular(args)
-- 	if is_singular > 1 then
-- 		local alt_names = clean_list_syntax(alt_name)
-- 		alt_names = split(alt_names)
-- 		for _, name in ipairs(alt_names) do
-- 			if not string.find(name, "''") then
-- 				return string.format(maintenance_categories.alt_name.category, "alt_name")
-- 			end
-- 		end
-- 	else
-- 		if string.find(alt_name, "''") then
-- 			return string.format(maintenance_categories.alt_name.category, "alt_name")
-- 		end
-- 	end
	
-- 	return ""
-- end