(* flunky *)
val path = if (!System.architecture=".hppa") then 
	"/users/staff/sez125/election/" else
	"/usr/local/etc/ftp/pub/a.cumming/election/";
use (path^"parse.sml");
val allFiles = map (fn s=>path^"1983."^s^".txt") ["01","02","03","04","05",
         "06","07","08","09","10", "11","12","13","14","15", "16","17"];
fun uniq l = let
  fun uniq' acc nil = acc
  |   uniq' acc(h::t) = if member acc h then uniq' acc t
  					else uniq' (h::acc) t
in uniq' nil l end;

(* Find the party which gained most seats in the most recent contest *)
fun flunky allFiles = let
  val allSeats = flatten(map read allFiles)
  val winners = map (party o hd o hd o rev o snd) allSeats
  val contenders = uniq winners
  fun countSeats p = length(filter (member [p]) winners)
  val psc = map (fn p => (p, countSeats p)) contenders
  val fl = fst(hd(sort (fn(a,b)=>snd a>snd b) psc))
in fl end;

(* Find the name of the MP for constituency number x *)
fun MP allFiles x = let
  val allConstituencies = flatten(map read allFiles)
  val targetConstituency = nth(allConstituencies,x-1)
  fun nameOf s = substring(s,24,min(30,size s - 24))
in nameOf(hd(hd(rev(snd targetConstituency)))) end;

(* Find the key Tory marginals - Conservative seat where the margin
   between the winner and the runner up is less than or equal to x *)
fun marginal allFiles x = let
  val allSeats = flatten(map read allFiles)
  fun isTorySeatP con = (party(hd(hd(rev(snd con))))="C      ")
  fun isMarginalP con = let
    val contest = hd(rev(snd con))
    val winner_votes = votes(hd contest)
    val runner_up_votes = votes(hd(tl contest))
  in winner_votes - runner_up_votes <= x end
  val targetSeats = filter (fn c => (isTorySeatP c) andalso (isMarginalP c))
		allSeats
in map fst targetSeats end;

(* Redistribute the seats based on popular vote - exclude parties with
   less than barValue% of the national vote *)
fun pr allFiles barValue = let
  val allSeats = flatten(map read allFiles)
  val contests = map (hd o rev o snd) allSeats
  val whoGotWhat = map (fn c => (party c,votes c)) (flatten contests)
  val contenders = uniq (map fst whoGotWhat)
  fun voteTot p = (p,sum(map snd(filter (fn(pn,_)=>pn=p)whoGotWhat)))
  val whoGotWhatCondensed = map voteTot contenders
  val bar = floor(real(sum(map snd whoGotWhatCondensed))*barValue/100.0)
  val newContenders = filter (fn(_,v)=> v>=bar) whoGotWhatCondensed
  val newVoteTot = real(sum(map snd newContenders))
  fun redistrib(p,v) = (p,650.0*(real v)/newVoteTot)
in filter (fn(_,v)=>v>0.5) (map redistrib newContenders) end;

(* Try them out *)
flunky allFiles;
MP allFiles 568;
app print (marginal allFiles 1000);
pr allFiles 5.0;