(******************************************************************************
** Copyright (c) 2004  <little@cs.utah.edu>
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public License
** as published by the Free Software Foundation; either version 2
** of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
** 
** To get a copy of the GNU General Public License, write to the 
** Free Software Foundation, Inc., 59 Temple Place - Suite 330, 
** Boston, MA 02111-1307, USA.
**
** File Name     : checkFcst.ml
** Author        : 
** E-mail        : little@cs.utah.edu
** Date Created  : 02/12/2004
**
** Description   : 
**
** Assumptions   :
**
** ToDo          :
**
*******************************************************************************
** CVS HOOKS
**
** $Source: /home/little/srl_cvs/school/hw/cs6520/ocaml/checkFcst.ml,v $ 
*******************************************************************************
** $Id: checkFcst.ml,v 1.1 2004/02/13 04:30:27 little Exp $ 
******************************************************************************)

open Http_client.Convenience
open OUnit
  
(* A data structure to hold forecast information. *)  
type forecast =
    {
      date : string;
      skyCond : string;
      highTemp : string;
      lowTemp : string;
      pop : string;
    }

(* A variable used to store the URL where the weather is found.
 *
 * string
 *)
let weatherURL = "http://www.wrh.noaa.gov/Saltlake/climate/STP.shtml"

(* Get the raw text from the given url.
 *
 * string -> string
 *)
let getPage url = http_get url

(* Get the test data and put it into a string.
 *
 * string
 *)                  
let getTestPage _ =
  let fileName = "testWeather.txt" in
  let fin = open_in fileName in
  let buf = Buffer.create 4096 in
  let rec loop() =
    let line = input_line fin in
      Buffer.add_string buf line;
      Buffer.add_char buf '\n';
      loop()
  in
    try
      loop()
    with
        End_of_file -> Buffer.contents buf
                    
(* A function that takes the forecast web page and parses out the
 * useful information.
 *
 * string -> string
 *)
let getPreData data =
  let startPrePos = Str.search_forward (Str.regexp "<pre>") data 0 in
  let firstPre = Str.string_after data startPrePos in
  let endPrePos = Str.search_forward (Str.regexp "</pre>") firstPre 0 in
  let preTagData = Str.string_before firstPre endPrePos in
  let startWeather = Str.search_forward
                    (Str.regexp "SALT LAKE CITY +: +") preTagData 0 in
  let dayStr = Str.string_after preTagData (Str.match_end()) in
  let endSLC = Str.search_forward (Str.regexp "[A-Z]") dayStr 0 in
    Str.string_before dayStr endSLC

(* Test getPreData
 *)
let testGetPreData _ =
  let p = getTestPage () in
  let preData = getPreData p in
    assert_equal preData "24 /  -4 /  0.00 /  0 /  7
 "
    
(* Parse the data generated by getPreData.
 *
 * string -> forecast
 *)
let parsePreData s =
  let time = Unix.localtime (Unix.time()) in
  let {Unix.tm_yday = yday;} = time in
  let weatherL = Str.split (Str.regexp " +/ +") s in
    { date = (string_of_int yday);
      skyCond = "";
      highTemp = List.nth weatherL 0;
      lowTemp = List.nth weatherL 1;
      pop = ""
    }

(* Test parsePreData
 *)
let testParsePreData _ =
  let time = Unix.localtime (Unix.time()) in
  let {Unix.tm_yday = yday;} = time in
  let p = getTestPage () in
  let preData = getPreData p in
  let res = parsePreData preData in
    assert_equal res {
      date = (string_of_int yday);
      skyCond = "";
      highTemp = "24";
      lowTemp = "-4";
      pop = ""
    }
    
(* Output the forecast to a string.
 *
 * forecast -> string
 *)
let printFcstOut f =
  Printf.sprintf "%s\t" f.date ^
  Printf.sprintf "%s\t" f.skyCond ^
  Printf.sprintf "%s\t" f.highTemp ^
  Printf.sprintf "%s\t" f.lowTemp ^
  Printf.sprintf "%s\n" f.pop
      
(* Output the forecast to a string with numbered fields.
 *
 * forecast -> string
 *)
let printFcstOutNum f =
  Printf.sprintf "1:%s\t" f.date ^
  Printf.sprintf "2:%s\t" f.skyCond ^
  Printf.sprintf "3:%s\t" f.highTemp ^
  Printf.sprintf "4:%s\t" f.lowTemp ^
  Printf.sprintf "5:%s\n" f.pop
      
(* Output the forecastList data structure to the given channel.
 *
 * forecast list -> out_channel -> unit
 *)
let outputFcstL l chan =
  let time = Unix.localtime (Unix.time ()) in
  let { Unix.tm_mon = mon;
        Unix.tm_mday = mday;
        Unix.tm_year = year;
        Unix.tm_yday = yday;
        Unix.tm_hour = hour;
        Unix.tm_min = min} = time in
    Printf.fprintf chan "Collected: %02d-%02d-%d @ %d:%d\n"
      (mon+1) mday (year+1900) hour min;
    Printf.fprintf chan "Date\tWeather\tHigh\tLow\tProb. of Precip.\n";
    Printf.fprintf chan "%s" (String.concat "" (List.map printFcstOut l))

(* Create a fcst record from a given line of the output file.
 *
 * string -> forecast
 *)
let fcst_of_line fcst =
  let fcstL = Str.split (Str.regexp "\t") fcst in
    { date = List.nth fcstL 0;
      skyCond = List.nth fcstL 1;
      highTemp = List.nth fcstL 2;
      lowTemp = List.nth fcstL 3;
      pop = List.nth fcstL 4
    }

(* Gets line # line from the provided input channel
 *
 * in_channel -> int -> string
 *)
let rec getLine fin line =
  match line with
      0 -> input_line fin
    | i -> let s = input_line fin in
        getLine fin (line - 1)
      
(* Determine the goodness of a forecast.
 *
 * forecast -> int -> int -> int -> unit
 *)
let calcGoodness res yday year pos =
  let fileName = (string_of_int (yday - pos)) ^ "-" ^
                 (string_of_int (1900 + year)) ^ ".fcst" in
  let fin = open_in fileName in
  let line =  getLine fin (pos + 2) in
  let fcst = fcst_of_line line in
    match (((abs (int_of_string (fcst.highTemp) -
                  int_of_string (res.highTemp))) > 4) &&
           ((abs (int_of_string (fcst.lowTemp) -
                  int_of_string (res.lowTemp))) > 4)) with
        true -> Printf.printf "Bad forecast %d day(s) ago.\n" (pos+1)
      | false -> Printf.printf "Good forecast %d day(s) ago.\n" (pos+1)
          
(* Checks the goodness of a forecast for a given number of days.
 *
 * forecast -> int -> int -> int -> int -> unit
 *)
let rec checkGoodness res days yday year pos =
  match (pos = days) with
      true -> ()
    | false -> calcGoodness res yday year pos;
        checkGoodness res days yday year (pos + 1)

(* Check the forecast for the given number of days.
 *
 * unit
 *)      
let checkFcst =
  let p = getPage weatherURL in
  let preData = getPreData p in
  let res = parsePreData preData in
  let days = int_of_string(Sys.argv.(2)) in
  let time = Unix.localtime (Unix.time()) in
  let {Unix.tm_yday = yday;
       Unix.tm_year = year} = time in
    checkGoodness res days (yday-1) year 0


let testCheckFcst _ =
  assert_equal "foo" "foo"
      
let suite = "Testing checkFcst" >::: ["testParsePreData" >:: testParsePreData;
                                      "testGetPreData" >:: testGetPreData]
      
let _ =
  let verbose = ref false in
  let set_verbose _ = verbose := true in
    Arg.parse
      [("-verbose", Arg.Unit set_verbose, "Run the test in verbose mode.");]
      (fun x -> ())
      ("usage: " ^ Sys.argv.(0) ^ " [-verbose]");
    if not (was_successful (run_test_tt ~verbose:!verbose suite)) then
      exit 1