enum Point {
  FILLED = "#",
  EMPTY = ".",
}

type Present = Point[][];
type Region = {
  width: number;
  height: number;
};
interface Tree {
  region: Region;
  presents: number[];
}

interface SituationSummary {
  presents: Present[];
  trees: Tree[];
}

export default async function ChristmasTreeFarm() {
}

function do_presents_fit(tree: Tree, presents: Present[]): boolean {
}

function do_present_pair_fit(tree: Tree, p_a: Present, p_b: Present): boolean {
}

function rotate_present_90_deg(present: Present): Present {
}

function flip_present_horizontal(present: Present): Present {
}

function flip_present_vertical(present: Present): Present {
}

export async function read_situation_summary(
  path: string,
): Promise<SituationSummary> {
  const txt_input = await Deno.readTextFile(path);
  // NOTE: should be done with splits to avoid performance issues on final sample
  const block_list = txt_input.split("\n\n");

  const present_list: Present[] = [];
  const tree_list: Tree[] = [];

  block_list.forEach((block) => {
    if (block.includes("x")) {
      // Tree
      const raw_trees = block.split("\n");
      raw_trees.forEach((t) => {
        if (!t || t.length < 1) {
          return;
        }
        const [raw_region, raw_presents] = t.split(": ");
        const region: Tree["region"] = {
          width: parseInt(raw_region.split("x")[0]),
          height: parseInt(raw_region.split("x")[1]),
        };
        const presents: Tree["presents"] = raw_presents.split(" ").map((p) => {
          const p_n = parseInt(p);
          if (p_n === p_n) {
            return p_n;
          }
          return undefined;
        }).filter((p) => p !== undefined);

        tree_list.push({ region, presents });
      });
    } else {
      // Present
      const raw_present = block.split("\n").slice(1);
      const present: Present = raw_present.map((line) =>
        line.split("").map((p) =>
          p === Point.FILLED ? Point.FILLED : Point.EMPTY
        )
      );
      present_list.push(present);
    }
  });

  return {
    presents: present_list,
    trees: tree_list,
  };
}