Module:Scale tree

---

local p = {}
local MOS = require('Module:MOS')
local ET = require('Module:ET')
local u = require('Module:Utils')
local rat = require('Module:Rational')
local sb = require('Module:SB tree')
local utils = require('Module:Utils')

-- Helper function that parses entries from a semicolon-delimited string and returns them in an array
-- TODO: Separate this and parse_pairs into its own module of helper functions, as they're included
-- in various modules at this point
function p.parse_entries(unparsed)
	local parsed = {}
	for entry in string.gmatch(unparsed, '([^;]+)') do
		local trimmed = entry:gsub("^%s*(.-)%s*$", "%1")
		table.insert(parsed, trimmed)		-- Add to array
	end
	return parsed
end

-- Helper function that parses pairs of elements separated by a colon
-- A pair must be two elements or it will be returned as an empty array
function p.parse_pair(unparsed)
	local parsed = {}
	for entry in string.gmatch(unparsed, '([^:]+)') do
		local trimmed = entry:gsub("^%s*(.-)%s*$", "%1")
		table.insert(parsed, trimmed)		-- Add to array
	end
	if #parsed == 2 then
		return parsed
	else
		return {}
	end
end

-- Function that takes a list of semicolon-delimited pairs and returns a map
-- (or dictionary or associative array) of key-value pairs
-- Each entry is colon-delimited as key : pair
function p.parse_kv_pairs(unparsed)
	-- Tokenize the string of unparsed pairs
	local parsed = p.parse_entries(unparsed)
	-- Then tokenize the tokens into key-value pairs
	local pairs_ = {}
	for i = 1, #parsed do
		local pair = p.parse_pair(parsed[i])
		if #pair == 2 then
			pairs_[pair[1]] = pair[2]
		end
	end
	return pairs_
end

-- Rewrite of scale tree function (has bugfixes and new formatting)
function p._scale_tree(input_mos, depth, comments)
	local input_mos = input_mos or MOS.new(5, 2)
	local depth = depth or 5
	local comments = comments or {}
	
	local equave = input_mos.equave
	local L = input_mos.nL		-- Large steps in mos
	local s = input_mos.ns		-- Small steps in mos
	local n = utils._gcd(L, s)		-- Number of periods
	local abstract_bright_gen = MOS.bright_gen(input_mos)
	
	local step_ratios = sb.sb_tree_ratios(depth)
	
	-- Default comments for TAMNAMS-named step ratios
	local default_comments = {}
	default_comments["1/1"] = "Equalized " .. MOS.as_string(mos)
	default_comments["4/3"] = "Supersoft " .. MOS.as_string(mos)
	default_comments["3/2"] = "Soft " .. MOS.as_string(mos)
	default_comments["5/3"] = "Semisoft " .. MOS.as_string(mos)
	default_comments["2/1"] = "Basic " .. MOS.as_string(mos)
	default_comments["5/2"] = "Semihard " .. MOS.as_string(mos)
	default_comments["3/1"] = "Hard " .. MOS.as_string(mos)
	default_comments["4/1"] = "Superhard " .. MOS.as_string(mos)
	default_comments["1/0"] = "Collapsed " .. MOS.as_string(mos)
	
	-- Create table
	local result = ""
	
	-- Table headers
	-- There are 6 columns:
	-- - Steps of ED
	-- - Bright and dark gens in cents
	-- - Step ratio and hardness
	-- - Comments
	result = '{| class="wikitable"\n'
	result = result .. '|+\n'
	result = result .. '! rowspan="2" | Generator (in steps)\n'
	result = result .. '! colspan="2" | Generator in cents\n'
	result = result .. '! rowspan="2" | Step ratio (hardness)\n'
	result = result .. '! rowspan="2" | Comments\n'
	result = result .. '|-\n'
	result = result .. '! Bright generator\n'
	result = result .. '! Dark generator\n'

	-- Rounding is done using string.format, to 3 decimal places (%.3f)
	
	-- Create each row of the table
	for i = 1, #step_ratios do
		local step_ratio = step_ratios[i]
		local steps_per_equave = step_ratio[1] * L + step_ratio[2] * s
		local steps_per_period = steps_per_equave / n
		local et = ET.new(steps_per_equave, equave)
		
		-- Calculate the bright gen and cent value
		local bright_generator_steps = step_ratio[1] * abstract_bright_gen['L'] + step_ratio[2] * abstract_bright_gen['s']
		local bright_generator_cents = ET.cents(et, bright_generator_steps)
		
		-- Calculate dark generator step count and cent value
		local dark_generator_steps = steps_per_period - bright_generator_steps
		local dark_generator_cents = ET.cents(et, dark_generator_steps)
		
		-- New row
		result = result .. "|-\n"	
		
		-- Cell for bright generator, as steps in et
		result = result .. string.format("| [[%s|%d%s]]\n", ET.as_string(et), bright_generator_steps, ET.backslash_modifier(et))
		
		-- Cells for generators in cents
		result = result .. string.format("| %.3f\n", bright_generator_cents)
		result = result .. string.format("| %.3f\n", dark_generator_cents)
		
		-- Cell for step ratio, with divide-by-zero check
		local hardness = -1
		if step_ratio[2] == 0 then
			hardness = "→ ∞"
		else
			hardness = string.format("%.3f", step_ratio[1] / step_ratio[2])
		end
		local step_ratio_as_string = string.format("%d:%d", step_ratio[1], step_ratio[2])
		result = result .. string.format("| %s (%s)\n", step_ratio_as_string, hardness)
		
		-- Cell for comment
		local key = step_ratios[i][1] .. "/" .. step_ratios[i][2]		-- The step ratio is (literally and figuratively) the key to add comments!
		
		-- Check for comments
		local contains_custom_comment = comments[key] ~= nil
		if contains_default_comment and contains_custom_comment then
			comment = comment .. default_comments[key] .. "<br>" .. comments[key]
		elseif contains_default_comment and not contains_custom_comment then
			comment = comment .. default_comments[key]
		elseif not contains_default_comment and contains_custom_comment then
			comment = comment .. comments[key]
		end
		
		local comment = comments[key] or ""
		result = result .. string.format("| %s\n", comment)
		
	end
	
	result = result .. "|}"
	return result

end

function p.scale_tree(frame)
	local mos = MOS.parse(frame.args["tuning"])
	local depth = frame.args["depth"] or 5
	local comments_unparsed = frame.args["Comments"] or ""
	local comments = p.parse_kv_pairs(comments_unparsed) or {}
	
	local result = p._scale_tree(mos, depth, comments)
	return result
end

return p