#include "shared.h"

#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/stat.h>
#include <paths.h>

void error(const char* format, ...) {
    va_list list;
    va_start(list, format);

    vfprintf(stderr, format, list);
    fprintf(stderr, "\n");
    exit(EXIT_FAILURE);
}

FILE* get_file_s(const char* path, const char* type) {
    struct stat s;
    if (lstat(path, &s) < 0) {
        if (type[0] != 'r') goto read;
        fprintf(stderr, "error: failed to read %s: %s\n", path, strerror(errno));
        return NULL;
    }
    if (S_ISDIR(s.st_mode)) {
        fprintf(stderr, "error: %s is a directory\n", path);
        return NULL;
    }

    FILE* file;
read:
    file = fopen(path, type);
    if (file == NULL) {
        fprintf(stderr, "error: failed to %s file %s: %s\n", type[0] == 'r' ? "read" : "write", path, strerror(errno));
    }
    return file;
}

FILE* get_file(const char* path, const char* type) {
    if (streql("-", path) && type[0] == 'r') {
        clearerr(stdin);
        return stdin;
    }
    FILE* file = get_file_s(path, type);
    if (file == NULL) exit(EXIT_FAILURE);
    return file;
}

long int get_number(const char* text) {
    char* end;
    long int n = strtol(text, &end, 10);
    if (text == end) {
        error("error: %s is not a valid number", text);
    }
    return n;
}

long int get_blkm(const char* text) {
    char* end;
    long int n = strtol(text, &end, 10);
    if (text == end) {
        error("error: %s is not a valid bkm", text);
    }
    if (*end == '\0') return n;
    switch (*end) {
        case 'K':
        case 'k':
            return n * 1024;
        case 'B':
        case 'b':
            return n * 512;
        case 'M':
        case 'm':
            return n * 1024 * 1204;
        default:
            error("error: invalid bkm type %c", *end);
    }
    // shouldnt get here anyways
    return 0;
}

bool streql(const char* a, const char* b) {
    if (*a != *b) return false;
    int n = 0;
    while (true) {
        if (*(a+n) != *(b+n)) return false;
        if (*(a+n) == '\0') return true;
        ++n;
    }
}

bool prefix(const char* pre, const char* str) {
    return strncmp(pre, str, strlen(pre)) == 0;
}

static char fs_types[5] = {'K','M','G','T','P'};
void print_file_size(size_t bytes, char buf[5]) {
    int index = 0;
    float next = bytes;
    while (true) {
        if (next < 1000) {
            break;
        }
        if (index == 5) {
            printf("999P");
            return;
        };
        next /= 1024;
        index++;
    }
    
    int n = snprintf(buf, 4, "%u", (int)(next+.5));
    if (index > 0) {
        buf[n] = (fs_types[index - 1]);
        n++;
    }
    buf[n] = '\0';
}

static char* months[12] = 
    {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
void print_date_time(time_t mills, char buf[13]) {
    struct tm* info;
    info = localtime(&mills);
    int n = snprintf(buf, 5, "%s ", months[info->tm_mon]);

    if (info->tm_mday < 10) {
        buf[n] = ' ';
        n++;
    }

    snprintf(buf + n, 13 - n, "%d %02d:%02d ", info->tm_mday, info->tm_hour, info->tm_sec);
}

#ifndef MAJOR
#define MAJOR 0
#endif

#ifndef MINOR
#define MINOR 0
#endif

#ifndef PATCH
#define PATCH 0
#endif

void check_arg (char* arg) {
    if (arg == NULL) {
        error("error: expected another argument after option");
    }
}

static void global_help(void (*help)(void)) {
    printf("LazySphere v%d.%d.%d multi-call binary.\n\n", MAJOR, MINOR, PATCH);
    help();
    exit(EXIT_SUCCESS);
}

void parse_help(int argc, char** argv, void (*help)(void)) {
    if (argc < 1) return;
    for (int i = 0; i < argc; i++) {
        if (!prefix("-", argv[i]) || streql("-", argv[i])) break;
        if (help != NULL && streql("--help", argv[i])) global_help(help);
    }
}

int parse_args(int argc, char** argv, void (*help)(void), int (*short_arg)(char, char*), int (*long_arg)(char*, char*)) {
    if (argc < 1) return 0;

    int start = 0;
    for (int i = 0; i < argc; i++) {
        if (!prefix("-", argv[i]) || streql("-", argv[i])) break;
        if (help != NULL && streql("--help", argv[i])) global_help(help);

        char* next_arg;
        if (i + 1 == argc) {
            next_arg = NULL;
        } else {
            next_arg = argv[i+1];
        }

        int current = i;

        if (prefix("--", argv[i])) {
            if (long_arg == NULL) {
                goto exit;
            }
            int r = long_arg(argv[current], next_arg);
            if (r == ARG_USED) {
                i++;
                start++;
            } else if (r == ARG_IGNORE) {
                goto exit;
            }
        } else {
            if (short_arg == NULL) {
                goto exit;
            }
            for (size_t j = 1; j < strlen(argv[current]); j++) {
                int r = short_arg(argv[current][j], next_arg);
                if (r == ARG_USED) {
                    i++;
                    start++;
                } else if (r == ARG_IGNORE) {
                    goto exit;
                }
            }
        }

        start++;
    }
exit:
    return start;
}

int get_tty() {
    int fd = open(_PATH_TTY, O_RDONLY);
    if (fd < 0) error("error: failed to get tty: %s", strerror(errno));
    return fd;
}

FILE* get_tty_stream(char* type) {
    int fd = get_tty();
    FILE* file = fdopen(fd, type);
    if (file == NULL) {
        error("error: failed to open tty stream: %s", strerror(errno));
    }
    return file;
}