/*
 * TODO:
 *   - application shouldn't be dying on all failures, have a way
 *     to configure that ... just die without calling exit()
 *   - look at at the jrk_sv_chop_delim_loop stuff. there must
 *     must be a better way of handling things.
 */

#include <stdint.h>

#ifdef JRK_IMPLEMENTATION_WITH_SHORTNAMES
  #define JRK_IMPLEMENTATION
  #define JRK_SHORTNAMES
#endif // JRK_IMPLEMENTATION_WITH_SHORTNAMES

typedef int8_t i8;
typedef int16_t i16;
typedef int32_t i32;
typedef int64_t i64;

typedef uint8_t u8;
typedef uint16_t u16;
typedef uint32_t u32;
typedef uint64_t u64;

typedef float f32;
typedef double f64;

#define JRK_UNUSED(x) (void)x
#define JRK_ARRSIZE(arr) (sizeof(arr) / sizeof(arr[0]))

typedef struct {
    u8 *data;
    u64 count;
    u64 capacity;
} jrk_Arena;

typedef struct {
    char *items;
    u64 count;
    u64 capacity;
} jrk_StringBuilder;

typedef struct {
    char *data;
    u64 count;
} jrk_StringView;

void *jrk_ecalloc(u64, u64);
void *jrk_erealloc(void*, u64);

jrk_Arena jrk_arena_create(u64);
void *jrk__arena_push(jrk_Arena*, u64);
void jrk_arena_expand(jrk_Arena*, u64);

i32 jrk_rand_num(i32);
i32 jrk_rand_num_range(i32, i32);

i32 jrk_fd_open_read(char*);
i32 jrk_fd_open_write(char*);
i32 jrk_fd_open_write_append(char*);
u64 jrk_fd_size(i32);
void jrk_fd_close(i32);

i32 jrk_sb_appendf(jrk_StringBuilder*, const char*, ...);
void jrk_sb_fd_read_all(jrk_StringBuilder*, i32);
u64 jrk_sb_fd_write_all(jrk_StringBuilder*, i32);
void jrk_sb_write_file(jrk_StringBuilder*, char*);
void jrk_sb_read_entire_file(jrk_StringBuilder*, char*);
void jrk_sb_append_buf_at(jrk_StringBuilder*, char*, u64, u64);

jrk_StringView jrk_sv_from_parts(char*, u64);
jrk_StringView jrk_sv_trim_right(jrk_StringView);
jrk_StringView jrk_sv_trim_left(jrk_StringView);
jrk_StringView jrk_sv_trim(jrk_StringView);
jrk_StringView jrk_sv_from_cstr(char*);
jrk_StringView jrk_sv_chop_delim(jrk_StringView*, char delim);

/* XXX: im not thrilled with this api, the memory can get messy real fast */
#define jrk_sv_chop_delim_loop(sv, it, delim) \
    for (jrk_StringView it = jrk_sv_chop_delim(sv, delim); it.count != 0; it = jrk_sv_chop_delim(sv, delim))

/* NOTE: no shortname as 'assert' is just too generic */
#define jrk_assert(c, msg) do { if (!(c)) jrk_die("jrk_assert: "msg); } while(0)
#define jrk_assertv(c, msg, ...) do { if (!(c)) jrk_diev("jrk_assert: "msg, __VA_ARGS__); } while(0)

#define jrk_shift(x, n) ((n)--, *(x)++)
#define jrk_shift_loop(x, n, it) for (char *it = jrk_shift(x, n); n >= 0; it = jrk_shift(x, n))

#define jrk_emalloc(n) jrk_ecalloc(1, n)

#define jrk_arena_destroy(arena) ((arena.data) ? free(arena.data) : (void) 0)
#define jrk_arena_push_array(arena, type, n) (type *) jrk__arena_push(arena, sizeof(type) * n)
#define jrk_arena_push_struct(arena, type) (type *) jrk__arena_push(arena, sizeof(type))

#define jrk_sb_to_sv(sb) jrk_sv_from_parts((sb).items, (sb).count)

#define JRK_DA_DEFAULT_INIT_CAPACITY 16
#define jrk_da_reserve(da, expected_capacity)                                               \
    do {                                                                                    \
        if ((expected_capacity) > (da)->capacity) {                                         \
            if ((da)->capacity == 0) {                                                      \
                (da)->capacity = JRK_DA_DEFAULT_INIT_CAPACITY;                              \
            }                                                                               \
            while ((expected_capacity) > (da)->capacity) {                                  \
                (da)->capacity *= 2;                                                        \
            }                                                                               \
            (da)->items = jrk_erealloc((da)->items, (da)->capacity * sizeof(*(da)->items)); \
        }                                                                                   \
    } while (0)

#define jrk_da_append(da, item)                \
    do {                                       \
        jrk_da_reserve((da), (da)->count + 1); \
        (da)->items[(da)->count++] = (item);   \
    } while (0);

#define jrk_da_append_many(da, new_items, new_items_count)                                      \
    do {                                                                                        \
        jrk_da_reserve((da), (da)->count + (new_items_count));                                  \
        memcpy((da)->items + (da)->count, (new_items), (new_items_count)*sizeof(*(da)->items)); \
        (da)->count += (new_items_count);                                                       \
    } while (0)

#define jrk_da_create(name, type) \
    struct name {                 \
        type *items;              \
        u64 count;                \
        u64 capacity;             \
    };                            \
    typedef struct name name

#define jrk_da_free(da)                                                   \
    do {                                                                  \
        jrk_assert((da).items, "bad free: jrk_da_free da.items is NULL"); \
        free((da).items);                                                 \
    } while (0)

#define jrk_da_foreach(type,it,da) for (type *it = (da)->items; it < (da)->items + (da)->count; ++it)

#define jrk_sb_append_null(sb) jrk_da_append(sb, '\0')
#define jrk_sb_free(sb) jrk_da_free(sb)

#define jrk_sb_append_cstr(sb, cstr)  \
    do {                              \
        const char *s = (cstr);       \
        i64 n = strlen(cstr);         \
        jrk_da_append_many(sb, s, n); \
    } while (0)

#define jrk_sb_append_buf(sb, buf, size) jrk_da_append_many(sb, buf, size)

#ifdef JRK_SHORTNAMES
  #define UNUSED               JRK_UNUSED
  #define ARRSIZE              JRK_ARRSIZE

  #define Arena                jrk_Arena
  #define StringBuilder        jrk_StringBuilder
  #define StringView           jrk_StringView

  #define sb_appendf           jrk_sb_appendf
  #define sb_append_null       jrk_sb_append_null
  #define sb_append_buf        jrk_sb_append_buf
  #define sb_append_buf_at     jrk_sb_append_buf_at
  #define sb_append_cstr       jrk_sb_append_cstr
  #define sb_free              jrk_sb_free
  #define sb_fd_read_all       jrk_sb_fd_read_all
  #define sb_fd_write_all      jrk_sb_fd_write_all
  #define sb_to_sv             jrk_sb_to_sv
  #define sb_write_file        jrk_sb_write_file
  #define sb_read_entire_file  jrk_sb_read_entire_file

  #define sv_trim_left         jrk_sv_trim_left
  #define sv_trim_right        jrk_sv_trim_right
  #define sv_trim              jrk_sv_trim
  #define sv_from_cstr         jrk_sv_from_cstr
  #define sv_from_parts        jrk_sv_from_parts
  #define sv_chop_delim        jrk_sv_chop_delim

  #define ecalloc              jrk_ecalloc
  #define erealloc             jrk_erealloc
  #define emalloc              jrk_emalloc

  #define da_reserve           jrk_da_reserve
  #define da_append            jrk_da_append
  #define da_append_many       jrk_da_append_many
  #define da_foreach           jrk_da_foreach
  #define da_create            jrk_da_create
  #define da_free              jrk_da_free

  #define arena_create         jrk_arena_create
  #define arena_destroy        jrk_arena_destroy
  #define arena_push_struct    jrk_arena_push_struct
  #define arena_push_array     jrk_arena_push_array
  #define arena_expand         jrk_arena_expand

  #define rand_num             jrk_rand_num
  #define rand_num_range       jrk_rand_num_range

  #define fd_close             jrk_fd_close
  #define fd_open_read         jrk_fd_open_read
  #define fd_open_write        jrk_fd_open_write
  #define fd_open_write_append jrk_fd_open_write_append

  #define shift                jrk_shift
  #define shift_loop           jrk_shift_loop
#endif // JRK_SHORTNAMES

#ifdef JRK_IMPLEMENTATION
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

#define jrk_die(x)                                                   \
    do {                                                             \
        fprintf(stderr, "%s:%d: error: "x" \n", __FILE__, __LINE__); \
        exit(69);                                                    \
    } while(0)

#define jrk_diev(x, ...)                                                              \
    do {                                                                              \
        fprintf(stderr, "%s:%d: error: "x"\n", __FILE__, __LINE__, __VA_ARGS__);      \
        exit(69);                                                                     \
    } while(0)

#define jrk_edie(x) jrk_diev(x": %s", strerror(errno))
#define jrk_ediev(x, ...) jrk_diev(x": %s", __VA_ARGS__, strerror(errno))

#ifdef JRK_SHORTNAMES
  #define die  jrk_die
  #define diev  jrk_diev
  #define edie jrk_edie
  #define ediev jrk_ediev
#endif // JRK_SHORTNAMES

void *
jrk_ecalloc(u64 nmemb, u64 size)
{
    void *p;

    if (!(p = calloc(nmemb, size)))
        jrk_ediev("jrk_ecalloc(%ld, %ld)", nmemb, size);
    return p;
}

void *
jrk_erealloc(void *ptr, u64 size)
{
    void *p;

    if (!(p = realloc(ptr, size)))
        jrk_ediev("jrk_erealloc(%p, %ld)", ptr, size);
    return p;
}

jrk_Arena
jrk_arena_create(u64 n)
{
    jrk_Arena result;
    result.count = 0;
    result.capacity = n;
    result.data = jrk_ecalloc(result.capacity, 1);
    return result;
}

void *
jrk__arena_push(jrk_Arena *arena, u64 n)
{
    while (arena->count + n >= arena->capacity)
        jrk_arena_expand(arena, arena->capacity * 2);

    void *result = &arena->data[arena->count];
    arena->count += n;
    return result;
}

void
jrk_arena_expand(jrk_Arena *arena, u64 new_capacity)
{
    u8 *tmp = jrk_erealloc(arena->data, new_capacity);

    arena->capacity = new_capacity;
    arena->data = tmp;
}

i32
jrk_sb_appendf(jrk_StringBuilder *sb, const char *fmt, ...)
{
    va_list args;
    va_start(args, fmt);
    i32 n = vsnprintf(NULL, 0, fmt, args);
    va_end(args);

    jrk_da_reserve(sb, sb->count + n + 1);
    va_start(args, fmt);
    vsnprintf(sb->items + sb->count, n + 1, fmt, args);
    va_end(args);
    sb->count += n;

    return n;
}

void
jrk_sb_append_buf_at(jrk_StringBuilder *sb, char *buf, u64 size, u64 idx)
{
    jrk_assertv(idx < sb->count, "jrk_sb_append_buf_at(%p, %p, %ld, %ld): idx is greater than sb->count",
                sb, buf, size, idx);

    u64 new_size = sb->count + size;
    char *temp = jrk_emalloc(new_size);

    memcpy(temp, sb->items, idx);
    memcpy(temp + idx, buf, size);
    memcpy(temp + idx + size, sb->items + idx, sb->count - idx);

    free(sb->items);
    sb->items = temp;
    sb->count = new_size;

    // NOTE: maybe keep it a proper ^2?
    sb->capacity = new_size;
}

u64
jrk_fd_size(i32 fd)
{
    struct stat statbuf = {0};
    if (fstat(fd, &statbuf) < 0)
        jrk_ediev("jrk_fd_size(%d)", fd);

    return statbuf.st_size;
}

void
jrk_sb_fd_read_all(jrk_StringBuilder *sb, i32 fd)
{
    u64 sz = jrk_fd_size(fd);
    jrk_da_reserve(sb, sz);
    if (read(fd, sb->items, sz) < 0)
        jrk_ediev("jrk_sb_fd_read_all(%p, %d)", (void *)sb, fd);

    sb->count = sz;
}

u64
jrk_sb_fd_write_all(jrk_StringBuilder *sb, i32 fd)
{
    i64 result;
    result = write(fd, (void *) sb->items, sb->count);
    if (result < 0)
        jrk_ediev("jrk_sb_fd_write_all(%p, %d)", (void *)sb, fd);

    return result;
}

void
jrk_fd_close(i32 fd)
{
    close(fd);
}

void
jrk_sb_write_file(jrk_StringBuilder *sb, char *path)
{
    i32 fd = jrk_fd_open_write(path);
    jrk_sb_fd_write_all(sb, fd);
    jrk_fd_close(fd);
}

void
jrk_sb_read_entire_file(jrk_StringBuilder *sb, char *path)
{
    i32 fd = jrk_fd_open_read(path);
    jrk_sb_fd_read_all(sb, fd);
    jrk_fd_close(fd);
}

i32
jrk_fd_open_read(char *path)
{
    i32 result = open(path, O_RDONLY);

    if (result < 0)
        jrk_ediev("jrk_fd_open_read(%s)", path);

    return result;
}

i32
jrk_fd_open_write(char *path)
{
    i32 result = open(path,
                     O_WRONLY | O_CREAT | O_TRUNC,
                     S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);

    if (result < 0)
        jrk_ediev("jrk_fd_open_write(%s)", path);

    return result;
}

i32
jrk_fd_open_write_append(char *path)
{
    i32 result = open(path,
                     O_WRONLY | O_CREAT | O_APPEND,
                     S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);

    if (result < 0)
        jrk_ediev("jrk_fd_open_write_append(%s)", path);

    return result;
}

jrk_StringView
jrk_sv_from_parts(char *data, u64 count)
{
    jrk_StringView result = {0};
    result.data = data;

    if (data[count] == '\0')
        result.count = count-1;
    else
        result.count = count;
    return result;
}

jrk_StringView
jrk_sv_from_cstr(char *data)
{
    jrk_StringView result = {0};
    result.data = data;
    result.count = strlen(data);
    return result;
}

jrk_StringView
jrk_sv_trim_right(jrk_StringView sv)
{
    u64 i = 0;
    for (; i < sv.count && isspace(sv.data[sv.count - 1 - i]); ++i);
    return jrk_sv_from_parts(sv.data, sv.count - i);
}

jrk_StringView
jrk_sv_trim_left(jrk_StringView sv)
{
    u64 i = 0;
    for (; i < sv.count && isspace(sv.data[i]); ++i);
    return jrk_sv_from_parts(sv.data + i, sv.count - i);
}

jrk_StringView
jrk_sv_trim(jrk_StringView sv)
{
    return jrk_sv_trim_right(jrk_sv_trim_left(sv));
}

jrk_StringView
jrk_sv_chop_delim(jrk_StringView *sv, char delim)
{
    u64 i = 0;
    while (i < sv->count && sv->data[i] != delim)
        ++i;

    jrk_StringView result = jrk_sv_from_parts(sv->data, i);

    if (i < sv->count) {
        sv->data += i + 1;
        sv->count -= i + 1;
    } else {
        sv->data += i;
        sv->count -= i;
        result.count++;
    }

    return result;
}

i32
jrk_rand_num(i32 upbound)
{
    return rand() % upbound + 1;
}

i32
jrk_rand_num_range(i32 min, i32 max)
{
    return rand() % (max - min + 1) + min;
}

#endif // JRK_IMPLEMENTATION