# Module:Medical cases chart/data

--- Example usage:
---
--- =p._externalData({datapage="COVID-19 cases in Santa Clara County, California.tab",datarecoveries="hospitalized",datacases="totalConfirmedCases"})  
local p = {}
local lang = mw.getContentLanguage
local english = mw.getLanguage("en")  
local function round(x)
return (math.modf(x + (x < 0 and -0.5 or 0.5)))
end  
local function formatChange(previous, current)
if not previous or previous == 0 then
return
end
if previous == current then
return "="
end  
local change = current / previous * 100 - 100
local sign = change < 0 and "−" or "+"
return mw.ustring.format("%s%s%%", sign, lang:formatNum(round(math.abs(change))))
end  
function p._externalData(args)
local data = mw.ext.data.get(args.datapage)  
local dateIndex
local deathsIndex
local recoveriesIndex
local casesIndex
local class4Index
local class5Index
for i, field in ipairs(data.schema.fields) do
if field.name == "date" or field.name == args.datadate then
dateIndex = i
elseif field.name == "deaths" or field.name == args.datadeaths then
deathsIndex = i
elseif field.name == "recoveries" or field.name == args.datarecoveries then
recoveriesIndex = i
elseif field.name == "cases" or field.name == args.datacases then
casesIndex = i
elseif field.name == "class4" or field.name == args.dataclass4 then
class4Index = i
elseif field.name == "class5" or field.name == args.dataclass5 then
class5Index = i
end
end
assert(dateIndex, "Date field not found.")
assert(deathsIndex or not args.datadeaths, "Deaths field not found.")
assert(recoveriesIndex or not args.datarecoveries, "Recoveries field not found.")
assert(casesIndex or not args.datacases, "Cases field not found.")
assert(class4Index or not args.dataclass4, "Class 4 field not found.")
assert(class5Index or not args.dataclass5, "Class 5 field not found.")  
-- Restructure the data as tables with keys.
local records = {}
for i, row in ipairs(data.data) do
local record = {
date = row[dateIndex],
deaths = deathsIndex and row[deathsIndex],
recoveries = recoveriesIndex and row[recoveriesIndex],
cases = casesIndex and row[casesIndex],
class4 = class4Index and row[class4Index],
class5 = class5Index and row[class5Index],
options = {},
streak = 1,
}
local prevRecord = records[#records] or {}
if casesIndex and not prevRecord.cases and record.cases and record.cases > 0 then
record.options.firstright1 = "y"
end
if deathsIndex and prevRecord.deaths == 0 and record.deaths and record.deaths > 0 then
record.options.firstright2 = "y"
end
if deathsIndex and (prevRecord.deaths or prevRecord.assumedDeaths) and not record.deaths then
record.assumedDeaths = prevRecord.deaths or prevRecord.assumedDeaths
end
if casesIndex and (prevRecord.cases or prevRecord.assumedCases) and not record.cases then
record.assumedCases = prevRecord.cases or prevRecord.assumedCases
end
if record.deaths == prevRecord.deaths
and record.recoveries == prevRecord.recoveries
and record.cases == prevRecord.cases
and record.class4 == prevRecord.class4
and record.class5 == prevRecord.class5 then
record.streak = prevRecord.streak + 1
end
table.insert(records, record)
end  
-- Collapse streaks of identical data.
for i = #records, 1, -1 do
local record = records[i]
if record.streak > 3 then
for j = i, i - record.streak + 3, -1 do
table.remove(records, j)
end
i = i - record.streak + 2
record = records[i]
record.options.collapse = "y"
record.options.id = english:formatDate("M", record.date):lower
record.date = nil
end
end  
-- Stringify the data.
local rows = {}
for i, record in ipairs(records) do
local prevRecord = records[i - 1] or {}
local row = {
record.date or "",
tostring(record.deaths or record.assumedDeaths or ""),
tostring(record.recoveries or ""),
tostring(record.cases or record.assumedCases or ""),
tostring(record.class4 or ""),
tostring(record.class5 or ""),
record.cases and lang:formatNum(record.cases) or "",
record.cases and formatChange(prevRecord.cases or prevRecord.assumedCases, record.cases) or "",
record.deaths and lang:formatNum(record.deaths) or "",
record.deaths and formatChange(prevRecord.deaths or prevRecord.assumedDeaths, record.deaths) or "",
}
for k, v in pairs(record.options) do
table.insert(row, string.format("%s=%s", k, v))
end
table.insert(rows, table.concat(row, ";"))
end
return table.concat(rows, "\n")
end  
function p.externalData
local args = {}
for k,v in pairs(.args) do
if (v or *) ~= * then
args['data'..k] = v
end
end
return p._externalData(args)
end
return p