#ifndef GUF_ASSERT_H
#define GUF_ASSERT_H
#include <stdio.h>
#include <assert.h>
#include "guf_common.h"

typedef enum guf_err {
    GUF_ERR_NONE = 0,
    GUF_ERR_UNSPECIFIED,
    GUF_ERR_ALLOC_FAIL,
    GUF_ERR_NULL_PTR,
    GUF_ERR_INT_OVERFLOW,
    GUF_ERR_DIV_BY_ZERO,
    GUF_ERR_DOMAIN,
    GUF_ERR_IDX_RANGE,
    GUF_ERR_INVALID_ARG,
    GUF_ERR_RUNTIME,
    GUF_ERR_LOGIC,
    GUF_ERR_NOT_FOUND,
    GUF_ERR_ALREADY_EXISTS,
    GUF_ERR_ASSERT_FAIL,
    GUF_ERR_TYPES_NUM
} guf_err;

typedef void(*guf_panic_handler_fn)(guf_err err, const char *msg);

extern guf_panic_handler_fn guf_global_panic_handler; 

extern void guf_set_global_panic_handler(guf_panic_handler_fn panic_handler);
extern void guf_panic_handler_default(guf_err err, const char *msg);
extern const char *guf_err_to_str(guf_err err);

#define GUF_FILE_LINE_STR() "file '" __FILE__ "' line " GUF_STRINGIFY(__LINE__)
#define GUF_ERR_MSG(msg) msg " (" GUF_FILE_LINE_STR() ")"
#define GUF_ERR_MSG_EMPTY() "(" GUF_FILE_LINE_STR() ")"

extern void guf_panic(guf_err err, const char *msg);

#define GUF_PANIC(err) guf_panic(err, "(" GUF_FILE_LINE_STR() ")");

// Break on debug, cf. https://nullprogram.com/blog/2022/06/26/ (last retrieved 2025-01-07)
#if __GNUC__ || __clang__
    #define GUF_DEBUG_BREAK_CODE __builtin_trap()
#elif _MSC_VER
    #define GUF_DEBUG_BREAK_CODE __debugbreak()
#else
    #define GUF_DEBUG_BREAK_CODE abort()
#endif

#ifndef NDEBUG
    #define GUF_ASSERT(COND) do { \
         if (!(COND)) { \
            guf_global_panic_handler(GUF_ERR_ASSERT_FAIL, "(assertion '" #COND "' " GUF_FILE_LINE_STR() ")"); \
            abort(); \
         }\
    } while(0);
#else
    #define GUF_ASSERT(COND)
#endif

#define GUF_ASSERT_RELEASE(COND) do { \
    if (!(COND)) { \
        guf_global_panic_handler(GUF_ERR_ASSERT_FAIL, "(release assertion '" #COND "' " GUF_FILE_LINE_STR() ")"); \
        abort();\
    } \
} while (0);

static inline void guf_err_set_or_panic(guf_err *err, guf_err err_val, const char *panic_msg)
{
    if (!err) {
        guf_panic(err_val, panic_msg);
    } else {
        *err = err_val;
    }
}

static inline void guf_err_set_if_not_null(guf_err *err, guf_err err_val)
{
    if (err) {
        *err = err_val;
    }
}
#endif

#ifdef GUF_INIT
#undef GUF_INIT
static const char *guf_err_type_str[] = {
    [GUF_ERR_NONE] = "Not an error", 
    [GUF_ERR_UNSPECIFIED] = "Error", 
    [GUF_ERR_ALLOC_FAIL] = "Allocation error",
    [GUF_ERR_NULL_PTR] = "Null pointer dereference",
    [GUF_ERR_DOMAIN] = "Domain error", 
    [GUF_ERR_INT_OVERFLOW] = "Integer overflow",
    [GUF_ERR_DIV_BY_ZERO] = "Division by zero",
    [GUF_ERR_IDX_RANGE] = "Index out of range",
    [GUF_ERR_INVALID_ARG] = "Invalid argument", 
    [GUF_ERR_NOT_FOUND] = "Not found error",
    [GUF_ERR_ALREADY_EXISTS] = "Already exists error",
    [GUF_ERR_RUNTIME] = "Runtime error", 
    [GUF_ERR_LOGIC] = "Logic error", 
    [GUF_ERR_ASSERT_FAIL] = "Assertion failed"
};

extern void guf_panic(guf_err err, const char *msg)
{
    if (!guf_global_panic_handler) {
        fputs("libguf panic (note: guf_global_panic_handler is NULL)\n", stderr);
        if (msg) {
            fputs(": ", stderr);
            fputs(msg, stderr);
        }
        abort();
    }
    guf_global_panic_handler(err, msg);
    abort(); // Just in case...
}

extern void guf_set_global_panic_handler(guf_panic_handler_fn panic_handler)
{
    guf_global_panic_handler = panic_handler;
}

extern const char *guf_err_to_str(guf_err err)
{
    if (GUF_STATIC_BUF_SIZE(guf_err_type_str) != GUF_ERR_TYPES_NUM) {
        puts("Note: size of guf_err_type_str != GUF_ERR_TYPES_NUM");
    }

    if (err < 0 || err >= GUF_ERR_TYPES_NUM) {
        return "Invalid error code";
    } else {
        if (err > GUF_STATIC_BUF_SIZE(guf_err_type_str)) {
            return "Invalid error string";
        }
        return guf_err_type_str[err];
    }
}

extern void guf_panic_handler_default(guf_err err, const char *msg)
{
    fputs("libguf panic: ", stderr);
    fputs(guf_err_to_str(err), stderr);
    fputc(' ', stderr);
    if (msg && err != GUF_ERR_NONE) {
        fputs(msg, stderr);
    }
    fputc('\n', stderr);

    #ifndef NDEBUG
        GUF_DEBUG_BREAK_CODE;
    #endif
    abort();
}

guf_panic_handler_fn guf_global_panic_handler = guf_panic_handler_default;

#endif