// Make ano object with all the directories keyed on directory full paths
export const getDirectories = (commandInput: string) => {
  const commands = commandInput.split("\n");

  const directories: Record<string, Record<string, string>> = {};
  // keep track of the current path to be able to push and pop directories
  let currentPath: string[] = ["/"];

  const handleChangeDir = (dir: string) => {
    switch (dir) {
      case "/":
        currentPath = ["/"];
        break;
      case "..":
        currentPath.pop();
        break;
      default:
        currentPath.push(dir);
    }
  };

  commands.forEach((command) => {
    // If it starts with $ then it's a command
    const commandMatch = command.match(/^\$ ([a-z]*) ?([a-z,A-Z,//,.]*)?/);
    if (commandMatch) {
      switch (commandMatch[1]) {
        case "cd":
          // handle change dir
          handleChangeDir(commandMatch[2]);
        case "ls":
        // eat list
      }
    } else {
      // otherwise it's a directory or a file
      const currentDirectory = currentPath.join(",");
      if (!directories[currentDirectory]) {
        directories[currentDirectory] = {};
      }
      const [first, name] = command.split(" ");
      if (first === "dir") {
        // put the directory in the object
        directories[currentDirectory][`${currentDirectory},${name}`] = first;
      } else {
        // put the file size in the object
        directories[currentDirectory][name] = first;
      }
    }
  });

  return directories;
};

// recursive function to populate the sizes of all the directories (assuming no loops)
const getDirectorySize = (
  directories: Record<string, Record<string, string>>,
  targetDir: string
) => {
  let size = 0;
  const directory = directories[targetDir];
  for (const key in directory) {
    if (directory[key] === "dir") {
      size += getDirectorySize(directories, key);
    } else {
      size += +directory[key];
    }
  }
  return size;
};

export const getTargetDirectoriesSize = (
  directories: Record<string, Record<string, string>>
) => {
  let sum = 0;
  let best = { dir: "fake", size: Infinity }; // start it off big
  const avail = 70000000 - getDirectorySize(directories, "/");
  const needed = 30000000 - avail;

  for (const key in directories) {
    const size = getDirectorySize(directories, key);
    // The best is the smallest directory that's big enough to free up at least the needed space
    if (size >= needed && size < best.size) {
      best = { dir: key, size };
    }
    // if it's too big we don't care anymore, don't bother...
    if (size <= 100000) {
      sum += size;
    }
  }
  return { sum, best };
};