Documentation for this module may be created at Mòideal:Teamplaid:Handle/doc

local Handle = { suite  = "Handle",
                 serial = "2019-07-14",
                 item   = 19644424 }
--[=[
Template:Handle   {{DOI}} {{HDL}}
require: URIutil
]=]
local Failsafe = Handle



local Config = {
   parProblem  = "problem",
   scheme      = false,
   doi         = { showArticle = "Digital Object Identifier",
                   showName    = "DOI",
                   stemURL     = "//doi.org/" },
   hdl         = { showArticle = false,
                   showName    = "Handle",
                   stemURL     = "//hdl.handle.net/" },
   errCat      = false,
   errClass    = "error_Handle",
   errClasses  = false,
   errHide     = false,
   errNS       = false,
   errDate     = { en = "Bad ISO year (month)",
                   de = "ISO-Jahr (ggf. Monat) fehlerhaft" },
   errInvalid  = { en = "Invalid:",
                   de = "Ungültig:" },
   errScheme   = { en = "Bad #invoke|scheme=" },
   errUnkown   = { en = "Unkown parameter:",
                   de = "Parameter unbekannt:" },
   problemNote = { en = "(currently unavailable)",
                   de = "(zurzeit nicht erreichbar)" }
}



Config.fault = function ( alert )
    -- Format error message by class=error
    -- Parameter:
    --     alert  -- string, error message
    -- Returns:
    --     string, HTML span
    return tostring( mw.html.create( "span" )
                            :addClass( "error" )
                            :wikitext( alert ) )
end -- Config.fault()



local function factory( apply )
    -- Localization of messages
    --     apply  -- string, with message key
    -- Returns message text; at least english
    local r
    entry = Config[ apply ]
    if entry then
        r = entry[ mw.language.getContentLanguage():getCode() ]
        if not r then
            r = entry.en
        end
    else
        r = Config.fault( string.format( "????.%s.????", apply ) )
    end
    return r
end -- factory()



local function faculty( adjust )
    -- Test template arg for boolean
    --     adjust  -- string or nil
    -- Returns boolean
    local r = false
    if adjust then
        r = mw.text.trim( adjust )
        if r ~= ""  and  r ~= "0" then
            r = true
        end
    end
    return r
end -- faculty()



local function failed( alert, add )
    -- Format message with class="error" or similar
    --     alert  -- string, with message key
    --     add    -- string, with additional information, or nil
    -- Returns message with markup
    local lucky, TemplUtl = pcall( require, "Module:TemplUtl" )
    local scope = Config.errClass
    local story = factory( alert )
    local r
    if add then
        story = string.format( "%s %s", story, add )
    end
    if Config.errClasses then
        scope = string.format( "%s %s", scope, Config.errClasses )
    end
    if type( TemplUtl ) == "table" then
        TemplUtl = TemplUtl.TemplUtl()
    end
    if type( TemplUtl ) == "table"  and
       type( TemplUtl.failure ) == "function" then
        r = TemplUtl.failure( story,
                              not Config.errHide,
                              scope,
                              Config.frame )
    else
        -- LEGACY and global wiki mode
        local element = mw.html.create( "span" )
                               :addClass( scope )
        if not Config.frame then
            Config.frame = mw.getCurrentFrame()
        end
        if Config.frame:preprocess( "{{REVISIONID}}" ) == "" then
            Config.errCat  = false
            Config.errHide = false
            element:addClass( "error" )
        end
        if Config.errHide then
            element:css( "display", "none" )
        end
        r = tostring( element:wikitext( story ) )
    end
    if Config.errCat then
        if Config.errNS then
            local ns = mw.title.getCurrentTitle().namespace
            local st = type( Config.errNS )
            if st == "string" then
                local space  = string.format( ".*%%s%d%%s.*", ns )
                local spaces = string.format( " %s ", Config.errNS )
                if spaces:match( space ) then
                    Config.errNS = false
                end
            elseif st == "table" then
                for i = 1, #Config.errNS do
                    if Config.errNS[ i ] == ns then
                        Config.errNS = false
                        break    -- for i
                    end
                end -- for i
            end
        end
        if not Config.errNS then
            r = string.format( "%s[[Category:%s]]", r, Config.errCat )
        end
    end
    return r
end -- failed()



local function fiat( access, args )
    -- Format template request
    --     access  -- string, with trimmed ID
    --     args    -- table, with template parameters
    -- Returns appropriate string
    local r, unknown
    for k, v in pairs( args ) do
        if k ~= 1  and
           k ~= "demo"  and
           k ~= "NoCat"  and
           k ~= Config.parProblem then
            if not unknown then
                unknown = { }
            end
            table.insert( unknown, k )
        end
    end -- for k, v
    if args.demo  or  faculty( args.NoCat ) then
        Config.errCat  = false
        Config.errHide = false
    end
    if unknown then
        local e = mw.html.create( "code" )
        e:wikitext( table.concat( unknown, " " ) )
        r = string.format( "'%s' in Template:%s",
                           tostring( e ), Config.scheme )
        r = failed( "errUnkown", r )
    else
        local lucky, URIutil = pcall( require, "Module:URIutil" )
        if lucky then
            if type( URIutil ) == "table" then
                URIutil = URIutil.URIutil()
            else
                URIutil = "library URIutil invalid"
            end
        end
        if type( URIutil ) ~= "table" then
            error( URIutil, 0 )
        end
        if URIutil[ "is" .. Config.showName ]( access )  then
            local suffer = args[ Config.parProblem ]
            r = URIutil[ "link" .. Config.showName ]( access )
            if Config.showArticle then
                r = string.format( "[[%s|%s]]:%s",
                                   Config.showArticle, Config.scheme, r )
            else
                r = string.format( "%s:%s", Config.scheme, r )
            end
            if suffer  and  suffer ~= "" then
                local scan = "^(2[01]%d%d)(%-?[01]?%d?)$"
                local s, sm = suffer:match( scan )
                local e
                if sm  and  sm ~= "" then
                    s = sm:match( "^%-([01]%d)$" )
                    if s then
                        local m = tonumber( s )
                        if m < 1  or  m > 12 then
                            s = false
                        end
                    end
                end
                if s then
                    e = mw.html.create( "small" )
                               :wikitext( factory( "problemNote" ) )
                    r = string.format( "%s %s", r, tostring( e ) )
                else
                    e = mw.html.create( "code" )
                               :wikitext( Config.parProblem .. "=" )
                    r = failed( "errDate", tostring( e ) )
                end
            end
        else
            r = failed( "errInvalid",
                        string.format( "%s=%s",
                                       Config.showName,
                                       mw.text.nowiki( access ) ) )
        end
    end
    return r
end -- fiat()



Handle.main = function ( argsF, argsT )
    -- Invocation; decide between first and secondary processing
    --     argsF  -- table, with #invoke parameters
    --     argsT  -- table, with template parameters
    -- Returns appropriate string
    local r = argsT[ 1 ]
    if r then
        local cnf = Config[ argsF.scheme ]
        if cnf then
            r = mw.text.trim( r )
            if r == ""  or
               r:find( cnf.stemURL, 1, true )  or
               r:find( Config.errClass, 1, true ) then
                argsF = false
            elseif r:find( "[[", 1, true ) then
                local seek = "%[%[%s*" .. argsF.scheme .. ":"
                if r:lower():find( seek ) then
                    argsF = false
                end
            end
            if argsF then
                Config.errCat     = argsF.errCat
                Config.errClasses = argsF.errClasses
                Config.errHide    = faculty( argsF.errHide )
                Config.errNS      = argsF.errNS
                if argsF.parProblem then
                    Config.parProblem = argsF.parProblem
                end
                Config.scheme = argsF.scheme
                if argsF.showArticle then
                    if argsF.showArticle == "" then
                        Config.showArticle = false
                    else
                        Config.showArticle = argsF.showArticle
                    end
                else
                    Config.showArticle = cnf.showArticle
                end
                Config.showName = cnf.showName
                r               = fiat( r, argsT )
            end
        else
            Config.errHide  = false
            Config.errClass = "error"
            r = failed( "errScheme", argsF.scheme )
        end
    else
        r = ""
    end
    return r
end -- Handle.main()



Failsafe.failsafe = function ( atleast )
    -- Retrieve versioning and check for compliance
    -- Precondition:
    --     atleast  -- string, with required version or "wikidata" or "~"
    --                 or false
    -- Postcondition:
    --     Returns  string  -- with queried version, also if problem
    --              false   -- if appropriate
    local last  = ( atleast == "~" )
    local since = atleast
    local r
    if last  or  since == "wikidata" then
        local item = Failsafe.item
        since = false
        if type( item ) == "number"  and  item > 0 then
            local entity = mw.wikibase.getEntity( string.format( "Q%d",
                                                                 item ) )
            if type( entity ) == "table" then
                local vsn = entity:formatPropertyValues( "P348" )
                if type( vsn ) == "table"  and
                   type( vsn.value ) == "string"  and
                   vsn.value ~= "" then
                    if last  and  vsn.value == Failsafe.serial then
                        r = false
                    else
                        r = vsn.value
                    end
                end
            end
        end
    end
    if type( r ) == "nil" then
        if not since  or  since <= Failsafe.serial then
            r = Failsafe.serial
        else
            r = false
        end
    end
    return r
end -- Failsafe.failsafe()



-- Export
local p = { }

p.f = function ( frame )
    local lucky, r
    Config.frame = frame
    lucky, r = pcall( Handle.main, frame.args, frame:getParent().args )
    if not lucky then
        r = Config.fault( string.format( "%s * %s",
                                         frame:getTitle(), r ) )
    end
    return r
end -- p.f()

p.failsafe = function ( frame )
    -- Versioning interface
    local s = type( frame )
    local since
    if s == "table" then
        since = frame.args[ 1 ]
    elseif s == "string" then
        since = frame
    end
    if since then
        since = mw.text.trim( since )
        if since == "" then
            since = false
        end
    end
    return Failsafe.failsafe( since )  or  ""
end -- p.failsafe()

p.Handle = function ()
    -- Module interface
    return Handle
end -- p.Handle()

return p