From 3e9ddba3a3711f532726b9e7272ae1548acaeb67 Mon Sep 17 00:00:00 2001
From: Andre Henriques <andr3h3nriqu3s@gmail.com>
Date: Mon, 12 Jun 2023 22:02:53 +0100
Subject: [PATCH] more work on the algorithm

---
 src/main.zig | 63 ++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 56 insertions(+), 7 deletions(-)

diff --git a/src/main.zig b/src/main.zig
index 50a9711..6e0a8e9 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -59,12 +59,14 @@ const BitWalker = struct {
             while (j < new_byte_pos) : (j += 1) {
                 new_mask = @shlExact(new_mask, 1) + 1;
             }
-            //print("{} mask: {b}, new_mask: {b}", .{ bits, old_mask, new_mask });
-            //print("here {b} {b}", .{ byte, old_mask });
-            //print("here_new {b} {b}", .{ next_byte, new_mask });
 
             var result = @shrExact(byte & old_mask, self.in_byte_position) + @shlExact(next_byte & new_mask, @intCast(u3, 8 - @as(u4, self.in_byte_position)));
 
+            print("mask: {b}, new_mask: {b}", .{ old_mask, new_mask });
+            print("here {b} {b}", .{ byte, old_mask });
+            print("here_new {b} {b}", .{ next_byte, new_mask });
+            print("result {}", .{result});
+
             self.position += 1;
             self.in_byte_position = new_byte_pos;
 
@@ -93,6 +95,48 @@ const BitWalker = struct {
     }
 };
 
+fn HuffmanGraph(valueType: type) type {
+    return struct {
+        const Node = struct {
+            left: ?Node,
+            right: ?Node,
+            value: valueType,
+            fn init() Node {}
+        };
+
+        head: Node,
+    };
+}
+
+const DynamicDecoder = struct {
+    const Self = @This();
+
+    len_to_read: usize,
+    codes: [19]u3,
+    walker: *BitWalker,
+
+    fn init(walker: *BitWalker, len_to_read: usize) !Self {
+        const list: [19]u8 = .{ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
+        var codes: [19]u3 = .{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+
+        for (0..(len_to_read + 4)) |i| {
+            print("{} {}", .{ walker.position, walker.in_byte_position });
+            var data: u3 = @intCast(u3, try walker.walk(3));
+            if (data == 0) {
+                continue;
+            }
+            print("{} - {}", .{ list[i], data });
+            codes[i] = data;
+        }
+
+        return .{
+            .len_to_read = len_to_read,
+            .codes = codes,
+            .walker = walker,
+        };
+    }
+};
+
 const LOCAL_FILE_HEADER_SIGNATURE = 0x04034b50;
 const ZipFileHeader = struct {
     version: u16,
@@ -171,9 +215,6 @@ const ZipFileHeader = struct {
 
         var lastBlock = try bitw.walk(1) == 1;
         var blockType = try bitw.walk(2);
-        var number_of_literal_codes = try bitw.walk(5);
-        var number_of_dist_codes = try bitw.walk(5);
-        var number_of_length_codes = try bitw.walk(5);
 
         if (lastBlock) {
             print("last block", .{});
@@ -187,9 +228,17 @@ const ZipFileHeader = struct {
             return error.unsuported_block_type;
         }
 
+        var number_of_literal_codes = try bitw.walk(5);
+        var number_of_dist_codes = try bitw.walk(5);
+        var number_of_length_codes = try bitw.walk(5);
+
         print("number of literal codes: {}", .{number_of_literal_codes});
         print("number of dist codes: {}", .{number_of_dist_codes});
-        print("number_of_length_coes: {}", .{number_of_length_codes});
+        print("number_of_length_codes: {}", .{number_of_length_codes});
+
+        var dynamic_decoder = try DynamicDecoder.init(&bitw, number_of_length_codes);
+
+        _ = dynamic_decoder;
 
         self.decompressed = true;
     }