with SDA_Exceptions;        use SDA_Exceptions;
with Ada.Text_IO;           use Ada.Text_IO;
with Ada.Command_Line;      use Ada.Command_Line;
with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
with googleNaive;

procedure pageRank is

    ERROR_args: Exception;

    procedure getArgs(filename: in out Unbounded_String;
                      iteMAX: in out Natural;
                      alpha: in out Float;
                      naif: in out Boolean) is
        i: Natural := 0;
    begin
        -- on vérifie d'abord que le nombre d'arguments est cohérent
        if not(0 < Argument_Count <= 6) then -- verif si double inégalité possible
            raise ERROR_args;
        else
            loop
                -- put(Argument(i));
                if Argument(i) = "-P" then
                    naif := True;
                    i := i + 1;
                elsif Argument(i) = "-A" then
                    alpha := Float'Value(Argument(i+1));
                    i := i + 2;
                elsif Argument(i) = "-I" then
                    iteMAX := Natural'Value(Argument(i+1)); -- verif si les conversions sont bonnes
                    i := i + 2;
                elsif Argument(i)(Argument(i)'Last-4 .. Argument(i)'Last) = ".net" then -- verif les indexs
                    filename := To_Unbounded_String(Argument(i)(Argument(i)'First .. Argument(i)'Last-5));
                    i := i + 1;
                else
                    raise ERROR_args;
                end if;
                exit when i > Argument_Count;
            end loop;
        end if;
    exception
        -- s'il y a un problème on arrête l'exectution et on affiche l'usage.
        when others =>
            put_line("Erreur lors de la saisi de la commande");
            put_line("Usage: pagerank [-I max_iterations] [-A alpha] [-P] fichier_reseau.net");
    end getArgs;

    procedure createG_naive(G: in out T_Google) is
        File : Ada.Text_IO.File_Type;
        N: Natural;
        H, S: T_Google;
        row, col: Natural;

        function rowSum(row: T_Row) return Natural is
            s: Natural := 0;
        begin
            for r in row loop
                s := s + r;
            end loop;
            return s;
        end rowSum;
    begin
        open(File, In_File, filename & ".net");
        get(File, N); -- on récupère le nombre de pages

        -- on créé H
        while not end_of_File(File) loop
            get(File, row);
            get(File, col);
            insert(H, row, col, 1.0);
        end loop;

        -- on créé S
        -- TODO: simplifier tout ça avec l'opérateur "/" sur T_row
        for row in H loop
            p = rowSum(row);
            for j in row loop
                if p = 0 then
                    row(j) := 1/N;
                else
                    if row(j) /= 0 then
                        row(j) := 1/p;
                    end if;
                end if;
            end loop;
        end loop;

        G := S*alpha + ones(N, N)*(1-alpha)/N;

    end createG_naive;

    filename: Unbounded_String;
    iteMAX: Natural := 150;
    naif: Boolean := False;
    alpha: Float := 0.85;

    epsilon: Float := 0.01;
    pi: T_Google;
    G: T_Google;
    N: Positive;

begin

    getArgs(filename, alpha, iteMAX, naif);
    
    initialize(pi, 1, N);
    initialize(G, N, N);
    createG_naive(G);

    for i in 1..N loop
       pi := pi * G;
    end loop;

    -- write2file(filename, pi); à implémenter

end pageRank;