Module:Geological time

require('strict')
local getArgs = require('Module:Arguments').getArgs
local catPair = require('Module:Category pair')._pair

local p = {}

-- Ordered list of eons, era, periods, etc. The code will search through
-- these lists for a match, then return an appropriate link to the timespans
-- adjacent to those matches

p.eon = {'Hadean', 'Archean', 'Proterozoic', 'Phanerozoic'}

p.era = {'Eoarchean', 'Paleoarchean', 'Mesoarchean', 'Neoarchean',
 'Paleoproterozoic', 'Mesoproterozoic', 'Neoproterozoic',
 'Paleozoic', 'Mesozoic', 'Cenozoic'}

p.period = {'Siderian', 'Rhyacian', 'Orosirian', 'Statherian',
 'Calymmian', 'Ectasian', 'Stenian',
 'Tonian', 'Cryogenian', 'Ediacaran',
 'Cambrian', 'Ordovician', 'Silurian', 'Devonian', 'Carboniferous', 'Permian',
 'Triassic', 'Jurassic', 'Cretaceous', 'Paleogene', 'Neogene', 'Quaternary'}

p.epoch = {'Terreneuvian', 'Cambrian Series 2', 'Miaolingian', 'Furongian',
 'Early Ordovician', 'Middle Ordovician', 'Late Ordovician',
 {base='Llandovery', dab='epoch'}, {base='Wenlock', dab='epoch'},
 {base='Ludlow', dab='epoch'}, {base='Pridoli', dab='epoch'},
 'Early Devonian', 'Middle Devonian', 'Late Devonian',
 {base='Mississippian', dab='(geology)'}, {base='Pennsylvanian',dab='(geology)'},
 'Cisuralian', 'Guadalupian', 'Lopingian',
 'Early Triassic', 'Middle Triassic', 'Late Triassic',
 'Early Jurassic', 'Middle Jurassic', 'Late Jurassic',
 'Early Cretaceous', 'Late Cretaceous',
 'Paleocene', 'Eocene', 'Oligocene',
 'Miocene', 'Pliocene', 'Pleistocene', 'Holocene'}

p.series = {'Furongian',
 'Lower Ordovician', 'Middle Ordovician', 'Upper Ordovician',
 'Llandovery', 'Wenlock', 'Ludlow', 'Pridoli',
 'Lower Devonian', 'Middle Devonian', 'Upper Devonian',
 'Lower Carboniferous', 'Upper Carboniferous',
 'Cisuralian', 'Guadalupian', 'Lopingian',
 'Lower Triassic', 'Middle Triassic', 'Upper Triassic',
 'Lower Jurassic', 'Middle Jurassic', 'Upper Jurassic',
 'Lower Cretaceous', 'Upper Cretaceous','Paleocene'}

p.age = {'Fortunian', 'Cambrian Stage 2', 'Cambrian Stage 3', 'Cambrian Stage 4',
 'Wuliuan', 'Drumian', 'Guzhangian', 'Paibian', 'Jiangshanian', 'Cambrian Stage 10',
 'Tremadocian', 'Floian', 'Dapingian', 'Darriwilian', 'Sandbian', 'Katian', 'Hirnantian',
 'Rhuddanian', 'Aeronian', 'Telychian', 'Sheinwoodian', 'Homerian', 'Gorstian', 'Ludfordian',
 'Lochkovian', 'Pragian', 'Emsian', 'Eifelian', 'Givetian', 'Frasnian', 'Famennian',
 'Tournaisian', 'Viséan', 'Serpukhovian', 'Bashkirian', {base='Moscovian', dab='(Carboniferous)'}, 'Kasimovian', 'Gzhelian',
 'Asselian', 'Sakmarian', 'Artinskian', 'Kungurian', 'Roadian', 'Wordian', 'Capitanian', 'Wuchiapingian', 'Changhsingian',
 'Induan', 'Olenekian', 'Anisian', 'Ladinian', 'Carnian', 'Norian', 'Rhaetian',
 'Hettangian', 'Sinemurian', 'Pliensbachian', 'Toarcian', 'Aalenian', 'Bajocian',
 'Bathonian', 'Callovian', {base='Oxfordian', dab='(stage)'}, 'Kimmeridgian', 'Tithonian',
 'Berriasian','Valanginian','Hauterivian','Barremian','Aptian','Albian',
 'Cenomanian','Turonian','Coniacian','Santonian','Campanian','Maastrichtian',
 'Danian','Selandian','Thanetian','Ypresian','Lutetian','Bartonian','Priabonian','Rupelian','Chattian',
 {base='Aquitanian', dab='(stage)'},'Burdigalian','Langhian','Serravallian','Tortonian','Messinian','Zanclean','Piacenzian',
 'Gelasian',{base='Calabrian', dab='(stage)'},'Calabrian','Late Pleistocene','Greenlandian','Northgrippian','Meghalayan'}

-- Determine whether a query string matches a stored timespan string
-- Arguments:
--   s: query string
--   sub: standard name of timespan
-- Returns:
--   false if there is no match
--   prefix and suffix of match, otherwise
local function matches(s, sub)
 local sLen = mw.ustring.len(s)
 local subLen = mw.ustring.len(sub)
 if subLen > sLen then
  return false
 end
 local lowerS = mw.ustring.lower(s)
 local lowerSub = mw.ustring.lower(sub)
 local startOffset, endOffset = mw.ustring.find(lowerS,lowerSub,1,true)
 if not startOffset then
  return false
 end
 return (mw.ustring.sub(s,1,startOffset-1) or ""), (mw.ustring.sub(s,endOffset+1) or "")
end

-- Create list of strings to search corresponding to a standard timespan
-- Some timespans are disambiguated: first search for the dabbed title, then
-- the base title. Otherwise just search for the standard timespan string
-- Argument:
--   span = value in timespan lists (above)
-- Returns:
--   list of strings to search in query string
local function searchStringList(span)
 if type(span) == "table" then
  return {span.base.." "..span.dab, span.base}
 end
 return {span}
end

-- When an adjacent time span is found, this function returns the
-- corresponding basename for the page.
-- Arguments:
--   span: adjacent entry from table, above
--   prefix: prefix of query string before match
--   suffix: remainder of original query string beyond match
-- Returns:
--   page title
--
-- If the adjacent time span is dabbed, then return the dab if the suffix
-- is empty. If the suffix is non-empty (e.g., "life"), append it to the base
-- name of the span (e.g., "Oxfordian") --> "Oxfordian life"
local function matchedString(span, prefix, suffix)
 if type(span) == "table" then
  if prefix == "" and suffix == "" then
   return span.base.." "..span.dab
  end
  return prefix..span.base..suffix
 end
 return prefix..span..suffix
end

-- Function to find the page titles of time spans adjacent to a query string
-- Arguments:
--   s: query string to search for
local function find(s)
 -- Search from most-specific to least, to catch "Cambrian Series 2" before "Cambrian"
 for _, list in ipairs({p.age, p.epoch, p.series, p.period, p.era, p.eon}) do
  local listLen = #list
  for i, span in ipairs(list) do
   -- Each timespan might have more than one search string
   for _, searchString in ipairs(searchStringList(span)) do
    local prefix, suffix = matches(s, searchString)
    if suffix then
     local prevSpan = i > 1 and matchedString(list[i-1], prefix, suffix)
     local nextSpan = i < listLen and matchedString(list[i+1], prefix, suffix)
     -- return first match found
     return {prev=prevSpan, next=nextSpan}
    end
   end
  end
 end
 return nil  
end

-- Lua entry point to generate see also hatnote for geological time spans adjanct in time
-- Arguments:
--   args[1]: name of page to generate adjacency (current page if None)
-- Returns:
--   See also previous and next, formatted as a hatnote
function p._seeAlso(args)
 local title = args[1] and mw.title.new(args[1]) or mw.title.getCurrentTitle()
 local basetext = title.baseText
 local namespace = title.namespace
 local adjacent = find(basetext)
 if not adjacent then
  local warning = require('Module:If preview')._warning
  local warn = warning({"Cannot find geological time frame in "..basetext})
  if mw.title.getCurrentTitle().nsText ~= "Template" then
   warn = warn.."[[Category:Missing geological time frame]]"
  end
  return warn
 end
 local prevTitle = adjacent.prev and mw.title.new(adjacent.prev, namespace)
 local nextTitle = adjacent.next and mw.title.new(adjacent.next, namespace)
 return catPair(prevTitle, nextTitle)
end

-- Function to find timespan before argument
function p._before(s)
 local findOut = s and find(tostring(s))
 return findOut and findOut.prev
end

-- Function to find timespan after argument
function p._after(s)
 local findOut = s and find(tostring(s))
 return findOut and findOut.next
end

-- Template entry points
function p.seeAlso(frame)
 local args = getArgs(frame)
 return p._seeAlso(args)
end

function p.before(frame)
 local args = getArgs(frame)
 return p._before(args[1]) or ""
end

function p.after(frame)
 local args = getArgs(frame)
 return p._after(args[1]) or ""
end

return p