const std = @import("std");

pub fn main() !void {
    const reader = std.io.getStdIn().reader();
    const writer = std.io.getStdOut().writer();

    //? Fibonacci calculation
    try writer.print("Fib Calc: \n", .{});
    const resFib: i8 = calcFib(5);
    std.debug.print("Fib Res: {d} \n", .{resFib});

    try writer.print("\n", .{});

    //? Zahlen raten 
    try writer.print("Zahlen raten: \n", .{});
    try zahlenRaten(reader, writer, 50);
}


pub fn calcFib(n: i8) i8 {
    if (n == 0) {
        return 1;
    }
    return n * calcFib(n - 1);
}


pub fn zahlenRaten(reader: anytype, writer: anytype,  upperLimit: i8) !void {
    const rand = std.crypto.random;
    const target: i64 = rand.intRangeLessThan(i64, 0, upperLimit);

    var counter: i8 = 0;

    while (true) {
        counter += 1;
        
        const guess = try getOneIntInput(reader, writer);

        if (guess < target) {
            try writer.print("{d} is too small \n", .{guess});
            continue;
        }

        if (guess > target) {
            try writer.print("{d} is too big \n", .{guess});
            continue;
        }

        try writer.print("{d} is the correct guess!\nIt took you {d} tries.\n", .{guess, counter});
        break;
    }
}

pub fn getOneIntInput(reader: anytype, writer: anytype) !i8 {
    var buff: [256]u8 = undefined;

    while(true) {
        try writer.print("> ", .{});
        const amountBytesRead = try reader.read(&buff);

        const uncleanData: []u8 = buff[0..(amountBytesRead - 1)];
        const data = std.mem.trimRight(u8, uncleanData, "\r\n");

        const guess = std.fmt.parseInt(i8, data, 10) catch |err|{
            switch (err) {
                error.InvalidCharacter => {
                    try writer.print("Invald character: {s}, try again! \n", .{data});
                },
                error.Overflow => {
                    try writer.print("Overflow: {s}, try again! \n", .{data});
                }
            }
            try writer.print("\n", .{});
            continue;
        };

        return guess;
    }
}