------------------------------------------------------------------------------
--  File:            Comp_Zip_Prc.adb
--  Description:     A Zip comparison tool using Zip-Ada lib.
--                   Demonstrates the Zip.Traverse procedure.
--                   See Comp_Zip for a command-line tool using it.
--  Author:          Gautier de Montmollin
------------------------------------------------------------------------------

with Ada.Text_IO;                       use Ada.Text_IO;
with Ada.Integer_Text_IO;               use Ada.Integer_Text_IO;
with Ada.Characters.Handling;           use Ada.Characters.Handling;
with Interfaces;                        use Interfaces;

with Zip;
with UnZip.Streams;                     use UnZip.Streams;

procedure Comp_Zip_Prc (
  z1, z2            :     Zip.Zip_info;
  quiet             :     Natural;
  password          :     String := "";
  total_differences : out Natural
)
is
  z : array (1 .. 2) of Zip.Zip_info;
  total_1,
  total_2,
  common,
  size_failures,
  compare_failures,
  missing_1_in_2,
  just_a_directory,
  missing_2_in_1 : Natural := 0;
  total_bytes : Integer_64 := 0;

  procedure Compare_1_file (file_name : String) is
    f : array (1 .. 2) of Zipped_File_Type;
    s : array (1 .. 2) of Stream_Access;
    c : array (1 .. 2) of Character;
    p : Integer_64 := 1;

    function Cut_name (n : String; l : Natural) return String is
      dots : constant String := "...";
    begin
      if n'Length > l then
        return dots & n (n'Last - (l - 1) + dots'Length .. n'Last);
      else
        return n;
      end if;
    end Cut_name;

    l : constant := 40;
    mininame : constant String := To_Lower (Cut_name (file_name, l));
    stuffing : constant String (1 .. l - mininame'Length + 1) := (others => ' ');

  begin
    if quiet = 0 then
      Put ("   [" & stuffing & mininame & "] ");
    end if;
    for i in 1 .. 2 loop
      begin
        Open (f (i), z (i), file_name, password);
        if i = 1 then
          total_1 := total_1 + 1;
        end if;
      exception
        when Zip.Entry_name_not_found =>
          if quiet = 0 then
            Put ("   # Not found in archive [" & Zip.Zip_name (z (i)) & ']');
          end if;
          if i = 1 then
            Put_Line ("-- internal error!");
          else
            Close (f (1));
          end if;
          if file_name (file_name'Last) = '/' or file_name (file_name'Last) = '\' then
            just_a_directory := just_a_directory + 1;
            if quiet = 0 then
              Put_Line (" (just a dir.)");
            end if;
          else
            if quiet = 0 then
              New_Line;
            end if;
          end if;
          missing_1_in_2 := missing_1_in_2 + 1;
          return;
      end;
      s (i) := Stream (f (i));
    end loop;
    --  File found, now the comparison:
    while not End_Of_File (f (1)) loop
      if End_Of_File (f (2)) then
        if quiet = 0 then
          Put_Line ("   # Shorter in [" & Zip.Zip_name (z (2)) & "] at position" &
                    Integer_64'Image (p));
        end if;
        Close (f (1));
        Close (f (2));
        size_failures := size_failures + 1;
        return;
      end if;
      --  Read one character in each stream
      for i in 1 .. 2 loop
        Character'Read (s (i), c (i));
      end loop;
      if c (1) /= c (2) then
        if quiet = 0 then
          Put_Line ("   # Difference at position" & Integer_64'Image (p));
        end if;
        Close (f (1));
        Close (f (2));
        compare_failures := compare_failures + 1;
        return;
      end if;
      p := p + 1;
    end loop;
    if not End_Of_File (f (2)) then
      if quiet = 0 then
        Put_Line ("   # Longer in [" & Zip.Zip_name (z (2)) & "]");
      end if;
      Close (f (1));
      Close (f (2));
      size_failures := size_failures + 1;
      return;
    end if;
    Close (f (1));
    Close (f (2));
    if quiet = 0 then
      Put_Line ("OK -" & Integer_64'Image (p - 1) & " bytes compared");
    end if;
    total_bytes := total_bytes + (p - 1);
  end Compare_1_file;

  procedure Compare_all_files is new Zip.Traverse (Compare_1_file);

  err_str : String (1 .. 5);

begin
  z (1) := z1;
  z (2) := z2;
  if quiet <= 3 then
    Put ("* Comparing [" & Zip.Zip_name (z (1)) & "] and [" & Zip.Zip_name (z (2)) & ']');
  end if;
  Compare_all_files (z (1));
  total_2 := Zip.Entries (z (2));
  common := total_1 - missing_1_in_2;
  if quiet < 2 then
    Put_Line ("* === Results ===");
    Put_Line ("  1st archive: [" & Zip.Zip_name (z (1)) & "], total files:" & Natural'Image (total_1));
    Put_Line ("  2nd archive: [" & Zip.Zip_name (z (2)) & "], total files:" & Natural'Image (total_2));
    Put_Line ("  Total files compared: " & Natural'Image (common));
    Put_Line ("  Total of correct bytes: " & Integer_64'Image (total_bytes));
  end if;
  missing_2_in_1 := total_2 - common;
  --  t2 - m21 = t1 - m12 = # common files
  total_differences :=
     size_failures + compare_failures +
     missing_1_in_2 + missing_2_in_1;
  case quiet is
    when 0 .. 2 =>
      New_Line;
      Put_Line ("* === Comparison summary ===");
      Put (err_str, size_failures);
      Put_Line ("    Size failures . . . . . . . . . . . :" & err_str);
      Put (err_str, compare_failures);
      Put_Line ("    Content comparison failures . . . . :" & err_str);
      Put (err_str, missing_1_in_2);
      Put ("    Files of 1st archive missing in 2nd :" & err_str);
      --
      if just_a_directory > 0 then
        Put_Line (" (" & Integer'Image (just_a_directory) & " useless dir. names)");
      else
        New_Line;
      end if;
      --
      Put (err_str, missing_2_in_1);
      for i in err_str'Range loop
        if err_str (i) = ' ' then err_str (i) := '_'; end if;
      end loop;
      Put_Line ("  __Files of 2nd archive missing in 1st :" & err_str & "__");
      --
      Put (err_str, total_differences);
      Put_Line ("  Total of errors . . . . . . . . . . . :" & err_str);
    when 3 =>
      if total_differences = 0 then
        Put_Line (" OK");
      else
        Put (err_str, total_differences);
        Put_Line (" Differences:" & err_str);
      end if;
    when others =>
      null;
  end case;
end Comp_Zip_Prc;