From 85503e88e1ce76d99d9be40492f77021364e63bd Mon Sep 17 00:00:00 2001
From: Tom van der Lee <t0m.vd.l33@gmail.com>
Date: Wed, 7 Dec 2022 11:44:48 +0100
Subject: Day 7

---
 day7/__init__.py | 181 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 181 insertions(+)
 create mode 100644 day7/__init__.py

(limited to 'day7/__init__.py')

diff --git a/day7/__init__.py b/day7/__init__.py
new file mode 100644
index 0000000..279201a
--- /dev/null
+++ b/day7/__init__.py
@@ -0,0 +1,181 @@
+# -*- coding: utf-8 -*-
+from abc import ABC
+from dataclasses import dataclass, field
+from enum import Enum
+from typing import Set, List, Optional, Tuple, Dict, Iterator, Any
+
+from aoc import BaseAssignment
+
+
+class Action(Enum):
+    ls = "ls"
+    cd = "cd"
+
+
+@dataclass(kw_only=True)
+class Command:
+    action: Tuple[Action, List[str]]
+    output: Optional[List[str]]
+
+    @classmethod
+    def from_input(cls, input: str) -> "Command":
+        action, *args = input[2:].split(" ")
+
+        return Command(action=(Action(action), args), output=[])
+
+
+@dataclass(kw_only=True)
+class Inode(ABC):
+    name: str
+    parent: "Folder" = None
+    size: int = NotImplemented
+
+
+@dataclass(kw_only=True)
+class Folder(Inode):
+    children: Dict[str, Inode] = field(default_factory=dict)
+
+    @property
+    def size(self) -> int:
+        return sum([inode.size for inode in self.children.values()])
+
+    @size.setter
+    def size(self, value: int):
+        pass
+
+    def __iter__(self):
+        yield self
+
+        for inode in self.children.values():
+            if isinstance(inode, Folder):
+                for item in iter(inode):
+                    yield item
+            else:
+                yield inode
+
+
+@dataclass(kw_only=True)
+class File(Inode):
+    pass
+
+
+@dataclass
+class FileSystem:
+    current: Folder = None
+    root: Folder = field(default_factory=lambda: Folder(name="/"))
+
+    capacity = 70000000
+
+    @classmethod
+    def from_commands(cls, commands: List[Command]) -> "FileSystem":
+        file_system = cls()
+
+        for command in commands:
+            file_system.parse_command(command)
+
+        return file_system
+
+    def __post_init__(self):
+        self.current = self.root
+
+    def parse_command(self, command: Command):
+        match command.action:
+            case [Action.ls, _]:
+                self.create_inodes(command.output or [])
+            case [Action.cd, arguments]:
+                self.change_directory(*arguments)
+
+    def create_inodes(self, inodes: List[str]):
+        for item in inodes:
+            size, name = item.split(" ")
+
+            inode = (
+                Folder(name=name, parent=self.current)
+                if size == "dir"
+                else File(name=name, parent=self.current, size=int(size))
+            )
+
+            if name in self.current.children:
+                raise Exception(f"File/Folder already exists {name}")
+
+            self.current.children[name] = inode
+
+    def change_directory(self, name: str):
+        match name:
+            case "..":
+                new_dir = self.current.parent
+            case "/":
+                new_dir = self.root
+            case name:
+                new_dir = self.current.children.get(name)
+
+        if new_dir is None or isinstance(new_dir, File):
+            raise Exception(f"No such folder {name}")
+
+        self.current = new_dir
+
+    def __iter__(self):
+        return iter(self.root)
+
+    @property
+    def free_space(self):
+        return self.capacity - self.root.size
+
+
+class Assignment(BaseAssignment, ABC):
+    @staticmethod
+    def parse_terminal_output(output: Iterator[str]) -> List[Command]:
+        commands = []
+        command = None
+
+        for item in output:
+            if item.startswith("$"):
+                if command is not None:
+                    commands.append(command)
+
+                command = Command.from_input(item)
+            else:
+                command.output.append(item)
+
+        if command is not None:
+            commands.append(command)
+
+        return commands
+
+
+class AssignmentOne(Assignment):
+    example_result = 95437
+
+    def run(self, input: Iterator) -> Any:
+        commands = self.parse_terminal_output(input)
+        file_system = FileSystem.from_commands(commands)
+
+        items = [
+            inode.size
+            for inode in file_system
+            if isinstance(inode, Folder) and inode.name != "/" and inode.size <= 100000
+        ]
+
+        return sum(items)
+
+
+class AssignmentTwo(Assignment):
+    example_result = 24933642
+
+    def run(self, input: Iterator) -> Any:
+        commands = self.parse_terminal_output(input)
+        file_system = FileSystem.from_commands(commands)
+
+        update_size = 30000000
+        space_to_free = update_size - file_system.free_space
+
+        eligible_for_deletion = sorted(
+            [
+                inode
+                for inode in file_system
+                if isinstance(inode, Folder) and inode.size >= space_to_free
+            ],
+            key=lambda node: node.size,
+        )
+
+        return eligible_for_deletion[0].size
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