Merge pull request #5 from mat-1/code-gen

Code gen

5 files changed, 310 insertions, 0 deletions

diff --git a/code-generator/README.md b/code-generator/README.md
new file mode 100644
index 00000000..5b9a6139
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+++ b/code-generator/README.md
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+Tools for generating code.
+
+The directory name doesn't start with `azalea-` because it's not a Rust crate.
+
+## Usage
+
+Generate packet:\
+`python main.py [packet id] [clientbound or serverbound] \[game/handshake/login/status\]`
diff --git a/code-generator/main.py b/code-generator/main.py
new file mode 100644
index 00000000..5ab3219f
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+++ b/code-generator/main.py
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+from mappings import Mappings
+import packetcodegen
+import requests
+import json
+import sys
+import os
+
+print(
+    f'\033[92mFinding Minecraft version...\033[m')
+version_manifest_data = requests.get(
+    'https://launchermeta.mojang.com/mc/game/version_manifest.json').json()
+minecraft_version = version_manifest_data['latest']['release']
+print(
+    f'\033[92mUsing \033[1m{minecraft_version}..\033[m')
+package_url = next(
+    filter(lambda v: v['id'] == minecraft_version, version_manifest_data['versions']))['url']
+package_data = requests.get(package_url).json()
+client_jar_url = package_data['downloads']['client']['url']
+
+skipping_burger = False
+try:
+    with open('burger.json', 'r') as f:
+        burger_data = json.load(f)[0]
+        if burger_data['version']['id'] == minecraft_version:
+            skipping_burger = True
+            print(
+                f'\033[92mSkipping Burger step because the burger.json is up-to-date.\033[m')
+except FileNotFoundError:
+    pass
+
+if not skipping_burger:
+    print('\033[92mDownloading Burger...\033[m')
+    r = os.system('git clone https://github.com/pokechu22/Burger')
+    os.system('cd Burger && git pull')
+    print('\033[92mDownloading client jar...\033[m')
+    with open('client.jar', 'wb') as f:
+        f.write(requests.get(client_jar_url).content)
+
+    print(f'\033[92mExtracting data with Burger...\033[m')
+    os.system(
+        'cd Burger && python munch.py ../client.jar --output ../burger.json')
+
+client_mappings_url = package_data['downloads']['client_mappings']['url']
+mappings = Mappings.parse(requests.get(client_mappings_url).text)
+
+with open('burger.json', 'r') as f:
+    burger_data = json.load(f)
+
+burger_packets_data = burger_data[0]['packets']['packet']
+packet_id, direction, state = int(sys.argv[1]), sys.argv[2], sys.argv[3]
+print(
+    f'Generating code for packet id: {packet_id} with direction {direction} and state {state}')
+packetcodegen.generate(burger_packets_data, mappings,
+                       packet_id, direction, state)
+
+os.system('cd .. && cargo fmt')
+
+print('Done!')
diff --git a/code-generator/mappings.py b/code-generator/mappings.py
new file mode 100644
index 00000000..fb3e8bda
--- /dev/null
+++ b/code-generator/mappings.py
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+class Mappings:
+    __slots__ = ('classes', 'fields', 'methods')
+
+    def __init__(self, classes, fields, methods):
+        self.classes = classes
+        self.fields = fields
+        self.methods = methods
+
+    @staticmethod
+    def parse(mappings_txt):
+        classes = {}
+        fields = {}
+        methods = {}
+
+        current_obfuscated_class_name = None
+
+        for line in mappings_txt.splitlines():
+            if line.startswith('#') or line == '':
+                continue
+
+            if line.startswith('    '):
+                # if a line starts with 4 spaces, that means it's a method or a field
+                if '(' in line:
+                    # if it has an opening parenthesis, it's a method
+                    real_name_with_parameters_and_line, obfuscated_name = line.strip().split(' -> ')
+                    real_name_with_parameters = real_name_with_parameters_and_line.split(
+                        ':')[-1]
+
+                    real_name = real_name_with_parameters.split('(')[0]
+                    parameters = real_name_with_parameters.split('(')[1]
+
+                    if current_obfuscated_class_name not in methods:
+                        methods[current_obfuscated_class_name] = {}
+                    methods[current_obfuscated_class_name][
+                        f'{obfuscated_name}({parameters})'] = real_name
+                else:
+                    # otherwise, it's a field
+                    real_name_with_type, obfuscated_name = line.strip().split(' -> ')
+                    real_name = real_name_with_type.split(' ')[1]
+
+                    if current_obfuscated_class_name not in fields:
+                        fields[current_obfuscated_class_name] = {}
+                    fields[current_obfuscated_class_name][obfuscated_name] = real_name
+            else:
+                # otherwise it's a class
+                real_name, obfuscated_name = line.strip(':').split(' -> ')
+                current_obfuscated_class_name = obfuscated_name
+
+                classes[obfuscated_name] = real_name
+
+        return Mappings(classes, fields, methods)
+
+    def get_field(self, obfuscated_class_name, obfuscated_field_name):
+        return self.fields.get(obfuscated_class_name, {}).get(obfuscated_field_name)
+
+    def get_class(self, obfuscated_class_name):
+        return self.classes[obfuscated_class_name]
+
+    def get_method(self, obfuscated_class_name, obfuscated_method_name, obfuscated_signature):
+        return self.methods[obfuscated_class_name][f'{obfuscated_method_name}({obfuscated_signature})']
diff --git a/code-generator/packetcodegen.py b/code-generator/packetcodegen.py
new file mode 100644
index 00000000..59a48535
--- /dev/null
+++ b/code-generator/packetcodegen.py
@@ -0,0 +1,169 @@
+from utils import to_snake_case, to_camel_case
+from mappings import Mappings
+import os
+
+
+def burger_type_to_rust_type(burger_type):
+    is_var = False
+    uses = set()
+
+    if burger_type == 'byte':
+        field_type_rs = 'i8'
+    elif burger_type == 'short':
+        field_type_rs = 'i16'
+    elif burger_type == 'int':
+        field_type_rs = 'i32'
+    elif burger_type == 'long':
+        field_type_rs = 'i64'
+    elif burger_type == 'float':
+        field_type_rs = 'f32'
+    elif burger_type == 'double':
+        field_type_rs = 'f64'
+
+    elif burger_type == 'varint':
+        is_var = True
+        field_type_rs = 'i32'
+    elif burger_type == 'varlong':
+        is_var = True
+        field_type_rs = 'i64'
+
+    elif burger_type == 'boolean':
+        field_type_rs = 'bool'
+    elif burger_type == 'string':
+        field_type_rs = 'String'
+
+    elif burger_type == 'chatcomponent':
+        field_type_rs = 'Component'
+        uses.add('azalea_chat::component::Component')
+    elif burger_type == 'identifier':
+        field_type_rs = 'ResourceLocation'
+        uses.add('azalea_core::resource_location::ResourceLocation')
+    elif burger_type == 'uuid':
+        field_type_rs = 'Uuid'
+        uses.add('uuid::Uuid')
+    elif burger_type == 'position':
+        field_type_rs = 'BlockPos'
+        uses.add('azalea_core::BlockPos')
+    elif burger_type == 'nbtcompound':
+        field_type_rs = 'azalea_nbt::Tag'
+    elif burger_type == 'itemstack':
+        field_type_rs = 'Slot'
+        uses.add('azalea_core::Slot')
+    elif burger_type == 'metadata':
+        field_type_rs = 'EntityMetadata'
+        uses.add('crate::mc_buf::EntityMetadata')
+    elif burger_type == 'enum':
+        # enums are too complicated, leave those to the user
+        field_type_rs = 'todo!()'
+    elif burger_type.endswith('[]'):
+        field_type_rs, is_var, uses = burger_type_to_rust_type(
+            burger_type[:-2])
+        field_type_rs = f'Vec<{field_type_rs}>'
+    else:
+        print('Unknown field type:', burger_type)
+        exit()
+    return field_type_rs, is_var, uses
+
+
+def write_packet_file(state, packet_name_snake_case, code):
+    with open(f'../azalea-protocol/src/packets/{state}/{packet_name_snake_case}.rs', 'w') as f:
+        f.write(code)
+
+
+def generate(burger_packets, mappings: Mappings, target_packet_id, target_packet_direction, target_packet_state):
+    for packet in burger_packets.values():
+        if packet['id'] != target_packet_id:
+            continue
+
+        direction = packet['direction'].lower()  # serverbound or clientbound
+        state = {'PLAY': 'game'}.get(packet['state'], packet['state'].lower())
+
+        if state != target_packet_state or direction != target_packet_direction:
+            continue
+
+        generated_packet_code = []
+        uses = set()
+        generated_packet_code.append(
+            f'#[derive(Clone, Debug, {to_camel_case(state)}Packet)]')
+        uses.add(f'packet_macros::{to_camel_case(state)}Packet')
+
+        obfuscated_class_name = packet['class'].split('.')[0]
+        class_name = mappings.get_class(
+            obfuscated_class_name).split('.')[-1].split('$')[0]
+
+        generated_packet_code.append(
+            f'pub struct {to_camel_case(class_name)} {{')
+
+        for instruction in packet.get('instructions', []):
+            if instruction['operation'] == 'write':
+                obfuscated_field_name = instruction['field']
+                if '.' in obfuscated_field_name or ' ' in obfuscated_field_name or '(' in obfuscated_field_name:
+                    continue
+                field_name = mappings.get_field(
+                    obfuscated_class_name, obfuscated_field_name)
+                if not field_name:
+                    generated_packet_code.append(f'// TODO: {instruction}')
+                    continue
+
+                field_type = instruction['type']
+                field_type_rs, is_var, instruction_uses = burger_type_to_rust_type(
+                    field_type)
+                if is_var:
+                    generated_packet_code.append('#[var]')
+                generated_packet_code.append(
+                    f'pub {to_snake_case(field_name)}: {field_type_rs},')
+                uses.update(instruction_uses)
+            else:
+                generated_packet_code.append(f'// TODO: {instruction}')
+                continue
+
+        generated_packet_code.append('}')
+
+        if uses:
+            # empty line before the `use` statements
+            generated_packet_code.insert(0, '')
+        for use in uses:
+            generated_packet_code.insert(0, f'use {use};')
+
+        print(generated_packet_code)
+        write_packet_file(state, to_snake_case(class_name),
+                          '\n'.join(generated_packet_code))
+        print()
+
+        mod_rs_dir = f'../azalea-protocol/src/packets/{state}/mod.rs'
+        with open(mod_rs_dir, 'r') as f:
+            mod_rs = f.read().splitlines()
+
+        pub_mod_line = f'pub mod {to_snake_case(class_name)};'
+        if pub_mod_line not in mod_rs:
+            mod_rs.insert(0, pub_mod_line)
+            packet_mod_rs_line = f'        {hex(packet["id"])}: {to_snake_case(class_name)}::{to_camel_case(class_name)},'
+
+            in_serverbound = False
+            in_clientbound = False
+            for i, line in enumerate(mod_rs):
+                if line.strip() == 'Serverbound => {':
+                    in_serverbound = True
+                    continue
+                elif line.strip() == 'Clientbound => {':
+                    in_clientbound = True
+                    continue
+                elif line.strip() in ('}', '},'):
+                    if (in_serverbound and direction == 'serverbound') or (in_clientbound and direction == 'clientbound'):
+                        mod_rs.insert(i, packet_mod_rs_line)
+                        break
+                    in_serverbound = in_clientbound = False
+                    continue
+
+                if line.strip() == '' or line.strip().startswith('//') or (not in_serverbound and direction == 'serverbound') or (not in_clientbound and direction == 'clientbound'):
+                    continue
+
+                line_packet_id_hex = line.strip().split(':')[0]
+                assert line_packet_id_hex.startswith('0x')
+                line_packet_id = int(line_packet_id_hex[2:], 16)
+                if line_packet_id > packet['id']:
+                    mod_rs.insert(i, packet_mod_rs_line)
+                    break
+
+            with open(mod_rs_dir, 'w') as f:
+                f.write('\n'.join(mod_rs))
diff --git a/code-generator/utils.py b/code-generator/utils.py
new file mode 100644
index 00000000..5336d574
--- /dev/null
+++ b/code-generator/utils.py
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+import urllib.request
+import gzip
+import json
+import re
+import io
+
+
+def to_snake_case(name):
+    s = re.sub('([A-Z])', r'_\1', name)
+    return s.lower().strip('_')
+
+
+def to_camel_case(name):
+    s = re.sub('_([a-z])', lambda m: m.group(1).upper(), name)
+    return s[0].upper() + s[1:]