Module:Climate chart

local p = {}
local cfg = mw.loadData('Module:Climate chart/configuration')

-- from https://lua-users.org/wiki/SimpleRound
local function round(num, decimal_places)
 local mult = 10^(decimal_places or 0)
 return math.floor(num * mult + 0.5) / mult
end

local function arg_or_default(args, from_arg, default)
 local arg = mw.text.trim(args[from_arg] or '')
 if arg ~= '' then
  return arg
 else
  return default
 end
end

-- we only draw using the metric numbers
local function compute_column_draw_data(metric_year, max_precipitation)
 local column_draw_data = {}
 -- so many magic constants
 local precipitation_scale = math.max(1, max_precipitation / 750) -- 750 mm is the maximum for height
 
 for _, month in ipairs(metric_year) do
  local precipitation_bar_height = month.precipitation / 50 / precipitation_scale -- 50 is a magic constant
  local temperature_bar_displacement = month.minimum / 5 + 8
  local temperature_bar_height = (month.maximum - month.minimum) / 5
  local temperature_high_displacement = month.maximum / 5 + 8
  local temperature_low_displacement = month.minimum / 5 + 6.5
  
  table.insert(column_draw_data, {
   precipitation_height = precipitation_bar_height,
   temperature_height = temperature_bar_height,
   temperature_displacement = temperature_bar_displacement,
   temperature_high_displacement = temperature_high_displacement,
   temperature_low_displacement = temperature_low_displacement
  })
 end
 
 return column_draw_data
end

local function present_monthly_temperature(temperature)
 local rounded_temp = round(temperature, 0)
 local temperature_sign = ''
 if rounded_temp < 0 then temperature_sign = '&minus;' end
 local abs_temp = math.abs(rounded_temp)
 
 return temperature_sign .. abs_temp
end

local function draw_column(month_draw_data, month_data)
 
 local precipitation = month_data.precipitation
 local precipitation_decimal_places = precipitation < 10 and 1 or 0
 local rounded_precipitation = round(precipitation, precipitation_decimal_places)
 
 local high_temp = present_monthly_temperature(month_data.maximum)
 local low_temp = present_monthly_temperature(month_data.minimum)
 
 local column = mw.html.create('div')
 column:addClass('climate-chart-column')
 :tag('div')
  :addClass('climate-chart-column-spacer')
  :wikitext('&nbsp;')
  :done()
 :tag('div')
  :addClass('climate-chart-column-precip-bar')
  :wikitext('&nbsp;')
  :css('height', month_draw_data.precipitation_height .. 'em')
  :css('print-color-adjust', 'exact') -- css sanitizer doesn't accept yet
  :done()
 :tag('div')
  :addClass('climate-chart-column-value climate-chart-column-precip')
  :tag('span')
   :wikitext(rounded_precipitation)
   :done()
  :done()
 :tag('div')
  :addClass('climate-chart-column-spacer2')
  :wikitext('&nbsp;')
  :done()
 :tag('div')
  :addClass('climate-chart-column-temp-bar')
  :wikitext('&nbsp;')
  :css('bottom', month_draw_data.temperature_displacement .. 'em' )
  :css('height', month_draw_data.temperature_height .. 'em')
  :css('print-color-adjust', 'exact') -- css sanitizer doesn't accept yet
  :done()
 :tag('div')
  :addClass('climate-chart-column-value climate-chart-column-high-temp')
  :css('bottom', month_draw_data.temperature_high_displacement .. 'em')
  :tag('span')
   :wikitext(high_temp)
   :done()
  :done()
 :tag('div')
  :addClass('climate-chart-column-value climate-chart-column-low-temp')
  :css('bottom', month_draw_data.temperature_low_displacement .. 'em')
  :tag('span')
   :wikitext(low_temp)
   :done()
  :done()
 :done()
 return column
end

local function header_row()
 local month_row = mw.html.create('tr')
 for _, month in ipairs(cfg.i18n.months) do
  month_row:tag('th')
   :attr('scope', 'col')
   :wikitext(month)
   :done()
 end
 
 return month_row:allDone()
end

local function fill_nice_tables(args)
 local primary_table = {}
 local secondary_table = {}
 for n = 2, 37, 3 do
  local minimum = tonumber(args[n])
  local maximum = tonumber(args[n+1])
  local precipitation = tonumber(args[n+2])
   -- we use the fact that `tonumber` returns nil if it gets not_a_string
   -- _OR_ the empty string later, since the defaults are unit-specific
  table.insert(primary_table, {
   minimum = minimum,
   maximum = maximum,
   precipitation = precipitation
  })
  table.insert(secondary_table, {
   minimum = minimum,
   maximum = maximum,
   precipitation = precipitation
  })
 end
 return primary_table, secondary_table
end

local function c_to_f(temperature_in_c)
 return temperature_in_c * 1.8 + 32
end

local function f_to_c(temperature_in_f)
 return (temperature_in_f - 32) * 5/9
end

local function mm_to_in(precipitation_in_mm)
 return precipitation_in_mm / 25.4 
end

local function in_to_mm(precipitation_in_in)
 return precipitation_in_in * 25.4
end

local function convert_inplace(t, convert_temperature, convert_precipitation)
 for _, month in ipairs(t) do
  month.minimum = convert_temperature(month.minimum)
  month.maximum = convert_temperature(month.maximum)
  month.precipitation = convert_precipitation(month.precipitation)
 end
end

local function fill_in_nils(year_t, default_t)
 for _, month in ipairs(year_t) do
  if not month.precipitation then month.precipitation = default_t.precipitation end
  if not month.maximum then month.maximum = default_t.temperature_high end
  if not month.minimum then month.minimum = default_t.temperature_low end
 end
end

local function chart_rows(args, imperial)
 local metric_t
 local imperial_t
 local maximum_precipitation = tonumber(args.maxprecip)
 local imperial_max_precipitation
 local metric_max_precipitation
 local default_max_precipitation = 1
 
 if imperial then
  imperial_t, metric_t = fill_nice_tables(args)
  fill_in_nils(metric_t, cfg.metric_default)
  fill_in_nils(imperial_t, cfg.imperial_default)
  convert_inplace(metric_t, f_to_c, in_to_mm, imperial)
  if maximum_precipitation then
   imperial_max_precipitation = maximum_precipitation
   metric_max_precipitation = in_to_mm(maximum_precipitation)
  else
   imperial_max_precipitation = default_max_precipitation
   metric_max_precipitation = default_max_precipitation
  end
 else
  metric_t, imperial_t = fill_nice_tables(args)
  fill_in_nils(metric_t, cfg.metric_default)
  fill_in_nils(imperial_t, cfg.imperial_default)
  convert_inplace(imperial_t, c_to_f, mm_to_in, imperial)
  if maximum_precipitation then
   metric_max_precipitation = maximum_precipitation
   imperial_max_precipitation = mm_to_in(maximum_precipitation)
  else
   metric_max_precipitation = default_max_precipitation
   imperial_max_precipitation = default_max_precipitation
  end
 end
 
 local column_draw_data = compute_column_draw_data(metric_t, metric_max_precipitation)
 
 local metric_row = mw.html.create('tr')
 local imperial_row = mw.html.create('tr')
 local function add_columns(row, year)
  for i = 1, 12 do
   row:tag('td')
    :node(draw_column(column_draw_data[i], year[i]))
    :done()
  end
 end
 
 add_columns(metric_row, metric_t)
 add_columns(imperial_row, imperial_t)
 
 return metric_row, imperial_row
 
end

local function present_chart_content(args, imperial)
 
 local primary_row, secondary_row
 if imperial then
  secondary_row, primary_row = chart_rows(args, imperial)
 else
  primary_row, secondary_row = chart_rows(args, imperial)
 end
 
 local primary = mw.html.create('table')
  :addClass('climate-chart-primary climate-chart-internal')
  :node(header_row())
  :node(primary_row)
  :done()
  
 local secondary_chart = mw.html.create('table')
  :addClass('climate-chart-secondary climate-chart-internal')
  :node(header_row())
  :node(secondary_row)
  :done()
 
 local secondary_title = imperial and cfg.i18n.secondary_title_metric or cfg.i18n.secondary_title_imperial
 -- primary has html_chart
 
 return primary, {
  title = secondary_title,
  chart = secondary_chart
 }
end

local function wrap_secondary_content(chart_content, temp_explanation, precip_explanation)
 local ret = mw.html.create('div')
 ret:addClass('climate-chart-secondary mw-collapsible mw-collapsed')
  :tag('div')
   :addClass('climate-chart-secondary-title')
   :wikitext(chart_content.title)
   :done()
  :tag('div')
   :addClass('mw-collapsible-content')
   :node(chart_content.chart)
   :node(temp_explanation)
   :node(precip_explanation)
   :done()
 return ret
end

local function explain_bar(bar_type, text)
 local ret = mw.html.create('p')
 ret:addClass('climate-change-explain-bar-' .. bar_type)
  :tag('span')
   :wikitext(cfg.i18n.explainer_key)
   :done()
  :wikitext(text)
  :done()
 return ret
end

local function explain(imperial, bar_type, imperial_explanation, metric_explanation)
 if imperial then
  return explain_bar(bar_type, imperial_explanation),
   explain_bar(bar_type, metric_explanation)
 else
  return explain_bar(bar_type, metric_explanation),
   explain_bar(bar_type, imperial_explanation)
 end
end

local function add_source(source)
 if not source then return end
 return mw.html.create('p'):wikitext(string.format(cfg.i18n.source, source))
end

local function add_title_content(title)
 local ret = mw.html.create()
 ret:tag('div')
  :addClass('climate-chart-title')
  :wikitext(title)
  :done()
 :tag('div')
  :addClass('climate-chart-explainer')
  :wikitext(cfg.i18n.explainer)
  :done()
 return ret
end

function p._main(args)
 
 local float = arg_or_default(args, cfg.arg.float, nil)
 local float_class = nil
 if float then
  if float == 'right' then
   float_class = 'climate-chart-right'
  elseif float == 'left' then
   float_class = 'climate-chart-left'
  end
 end
 
 local clear = arg_or_default(args, cfg.arg.clear, nil) or float
 local units = string.lower(arg_or_default(args, cfg.arg.units, ''))
 local is_imperial_primary = units == cfg.keyword.imperial
 local title = add_title_content(arg_or_default(args, cfg.arg.title, ''))
 local primary_chart, secondary_chart_content = present_chart_content(
  args,
  is_imperial_primary
 )
 local primary_temp_explanation, secondary_temp_explanation = explain(
  is_imperial_primary,
  'temp',
  cfg.i18n.explainer_fahrenheit,
  cfg.i18n.explainer_celsius
 )
 local primary_precip_explanation, secondary_precip_explanation = explain(
  is_imperial_primary,
  'precip',
  cfg.i18n.explainer_in,
  cfg.i18n.explainer_mm
 )
 
 local source = add_source(arg_or_default(args, 'source', nil))
 
 local secondary_content = wrap_secondary_content(
  secondary_chart_content,
  secondary_temp_explanation,
  secondary_precip_explanation
 )
 
 local climate_chart = mw.html.create('div')
 climate_chart:addClass('climate-chart')
  :addClass(float_class)
  :css('clear', clear)
 
 climate_chart:node(title)
  :node(primary_chart)
  :node(primary_temp_explanation)
  :node(primary_precip_explanation)
  :node(source)
  :node(secondary_content)
  :allDone()
 return mw.getCurrentFrame():extensionTag{
  name = 'templatestyles', args = { src = 'Module:Climate chart/styles.css' }
 } .. tostring(climate_chart)
end

function p.main(frame)
 return p._main(frame:getParent().args)
end

return p