const std = @import("std");
const slurp = @import("util/file.zig").slurp;

var gpa = std.heap.GeneralPurposeAllocator(.{}){};
const allocator = gpa.allocator();

const Hand = enum(u8) { Rock = 1, Paper = 2, Scissors = 3 };
const Outcome = enum(u8) { Win = 6, Draw = 3, Lose = 0 };

const KV_Hand = struct { @"0": []const u8, @"1": Hand };
const KV_Outcome = struct { @"0": []const u8, @"1": Outcome };

const Player_A_KV = std.ComptimeStringMap(Hand, [_]KV_Hand{
    .{ .@"0" = "A", .@"1" = .Rock },
    .{ .@"0" = "B", .@"1" = .Paper },
    .{ .@"0" = "C", .@"1" = .Scissors },
});

const Outcome_KV = std.ComptimeStringMap(Outcome, [_]KV_Outcome{
    .{ .@"0" = "X", .@"1" = .Lose },
    .{ .@"0" = "Y", .@"1" = .Draw },
    .{ .@"0" = "Z", .@"1" = .Win },
});

pub fn main() !void {
    const file_buffer = try slurp(allocator, "./input");
    defer allocator.free(file_buffer);

    var iter = std.mem.split(u8, file_buffer, "\n");

    var score: u16 = 0;

    while (iter.next()) |line| {
        if (line.len > 0)
            score += match(
                Player_A_KV.get(&[_]u8{line[0]}).?,
                Outcome_KV.get(&[_]u8{line[2]}).?,
            );
    }

    std.debug.print("{d}\n", .{score});
}

fn match(a: Hand, b: Outcome) u8 {
    switch (a) {
        .Rock => {
            switch (b) {
                .Win => return @enumToInt(b) + @enumToInt(Hand.Paper),
                .Lose => return @enumToInt(b) + @enumToInt(Hand.Scissors),
                .Draw => return @enumToInt(b) + @enumToInt(Hand.Rock),
            }
        },
        .Paper => {
            switch (b) {
                .Win => return @enumToInt(b) + @enumToInt(Hand.Scissors),
                .Lose => return @enumToInt(b) + @enumToInt(Hand.Rock),
                .Draw => return @enumToInt(b) + @enumToInt(Hand.Paper),
            }
        },
        .Scissors => {
            switch (b) {
                .Win => return @enumToInt(b) + @enumToInt(Hand.Rock),
                .Lose => return @enumToInt(b) + @enumToInt(Hand.Paper),
                .Draw => return @enumToInt(b) + @enumToInt(Hand.Scissors),
            }
        },
    }
}