#include <stdio.h>
#include <stdlib.h>
#include "maybe.h"


#define unless(expr) if (!(expr))

#define between(value, min, max) (({ \
    __typeof__(value) _value = (value); \
    __typeof__(min) _min = (min); \
    __typeof__(max) _max = (max); \
    _value >= _min && _value <= _max; \
}))



#define unwrap_or_else(option, else_block) ({ \
    __typeof__(option) _option_##__LINE__ = (option); \
    if (!_option_##__LINE__.tag) else_block; \
    _option_##__LINE__.value; \
})

#define unwrap_or_else2(option, else_block) ({ \
    __typeof__(option) _option_##__LINE__ = (option); \
    if (!_option_##__LINE__.tag) { \
        __typeof__(option.err) err = _option_##__LINE__.err; \
        else_block; \
    } \
    _option_##__LINE__.value; \
})

#define unwrap(option) ({ \
    __typeof__(option) _option_##__LINE__ = (option); \
    if (!_option_##__LINE__.tag) { \
        fprintf(stderr, "FATAL: File \"%s\", line %d, in %s\n", __FILE__, __LINE__, __func__); abort(); \
    } \
    _option_##__LINE__.value; \
})

#define unwrap_err(result) ({ \
    __typeof__(result) _result_##__LINE__ = (result); \
    if (_result_##__LINE__.tag) { \
        fprintf(stderr, "FATAL: File \"%s\", line %d, in %s\n", __FILE__, __LINE__, __func__); abort(); \
    } \
    _result_##__LINE__.err; \
})

#define result_map(result, func) ({ \
    __typeof__(result) _result = (result); \
    if (_result.tag) _result.value = func(_result.value); \
    _result; \
})

#define result_map_err(result, func) ({ \
    __typeof__(result) _result = (result); \
    if (!_result.tag) _result.err = func(_result.err); \
    _result; \
})

#define unwrap_or_else3(result, var, else_block) ({ \
    __typeof__(result) _result = (result); \
    var = _result.err; \
    _result.tag ? _result.value : (else_block); \
})


Option(int) get_foo(bool a) {
    printf("get_foo() called\n");
    return a ? Some(5) : None(int);
}

Result(str, int) get_string(bool a) {
    printf("get_string() called\n");
    return a ? Ok("Hello, world!", int) : Err(str, 66);
}

int foo() {
    puts("Computing foo");
    return 5;
}


str hello(str value) {
    printf("hello: %s\n", value);
    return "foo!";
}

int main() {
/*
    unless (i == 0 || i == 1) {
        printf("Hello!\n");
    }
*/
    if between(foo(), 1, 8) {
        printf("Hello!\n");
    }

    int x = unwrap_or(get_foo(false), 66);

    printf("x = %d\n", x);

    int z = unwrap_or_else(get_foo(true), {
        return 1;
    });

    printf("z = %d\n", z);

    int a = unwrap(get_foo(true));

    printf("a %d\n", a);

    Result(str, int) b = get_string(false);


    int c = unwrap_err(b);

    printf("c %d\n", c);

    str d = unwrap_or(get_string(true), "foo!");
    printf("d %s\n", d);

    str e = unwrap_or_else2(get_string(false), {
        printf("> %d\n", err);
    });

    Result(str, int) f = result_map(get_string(false), hello);
    printf("f %d\n", f.err);


    str g = unwrap_or_else3(get_string(true), int err, {
        printf("?? %i\n", err);
        goto error;
        "";
    });

    //Result(str, int) xx = Ok(100, int);


    //Result(str, int) l = Ok(5, int);


/*
    int c;
    if unwrap(get_foo(true), c) {
        printf("Hello, world!\n%d\n", c);
    }
*/
    //int y = expect(get_foo(true), "the world is collapsing!");
/*
    int i = unwrap_or( get_foo(true) ) {
        printf("fuck!\n");
    }
*/
ret:
    return 0;
error:
    return 1;
}