/* SPDX-License-Identifier: Apache-2.0 */

/* Copyright 2025 Thorsten Töpper
 *
 * vim:ts=4:sw=4:expandtab
 */

#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <time.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <errno.h>

#include "output.h"
#include "data_management.h"
#include "options.h"



/* === DEFINITIONS === */

#define out_vsep fputc('|', stdout)

#define out_print_newline() fputc('\n', stdout)
#define out_print_fname(x) printf(" %s ", x->fname)

void out_print_size(struct list_node *ptr);
void out_print_time(time_t tv);
void out_print_time_by_option(struct list_node *ptr);
void out_print_type(struct list_node *ptr);


/* === IMPLEMENTATION === */

inline int fputc_all_cols(char c, FILE *fdout) {
    struct winsize terminal;
    if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &terminal) == -1) {
        if (errno != 25) {
            LOGERR("ERROR: ioctl(STDOUT_FILENO, TIOCGWINSZ,...) failed: %s (errno %d)\n",
                    strerror(errno), errno);
        }
        terminal.ws_col = 72;
    }
    DBGTRC("DEBUG: terminal.ws_col = %d / terminal.ws_row = %d\n", terminal.ws_col, terminal.ws_row);
    /* Somehow not always ws_col == 0, with optimization compiler flags and executed by watch. */
    if (terminal.ws_col == 0) {
        terminal.ws_col = 72;
    }
    return fputc_width_x(c, terminal.ws_col, fdout);
}


/* Not the most performant way, but during output the time critical tasks are already done. */
inline int fputc_width_x(char c, size_t x, FILE *fdout) {
    size_t i=0;

    if (fdout == NULL) {
        LOGERR("ERROR: No output stream given.\n");
        return EOF;
    }

    if ( ! isprint(c) ) { c = '?'; }

    for (i=0; i<x; i++) {
        if (fputc(c, fdout) == EOF) {
            LOGERR("ERROR: Failed to write char 0x%02X to stream %d\n", c, fdout->_fileno);
            return EOF;
        }
    }

    return 1;
}



/* === FORMATTING RELATED FUNCTIONS === */
inline void out_print_size(struct list_node *ptr) {
    printf(" %8ld %2s ", ((ptr->ln_stat.st_size>=1024) ? (ptr->ln_stat.st_size/1024) : ptr->ln_stat.st_size),
            ((ptr->ln_stat.st_size >= 1024) ? "kB" : ""));
}

inline void out_print_time(time_t tv) {
    struct tm *tm = NULL;
    char timestamp[128];

    tm = localtime(&tv);
    if (option_timestamp_long) {
        strftime(timestamp, sizeof(timestamp), "%Y%m%d %H:%M:%S %Z", tm);
        printf(" %20s ", timestamp);
    } else {
        strftime(timestamp, sizeof(timestamp), "%H:%M:%S", tm);
        printf(" %8s ", timestamp);
    }
}

inline void out_print_time_by_option(struct list_node *ptr) {
    time_t time_value = 0;

    switch (option_time_field) {
        case 'm':
            time_value = ptr->ln_stat.st_mtim.tv_sec;
            break;
        case 'a':
            time_value = ptr->ln_stat.st_atim.tv_sec;
            break;
        case 'c':
            time_value = ptr->ln_stat.st_ctim.tv_sec;
            break;
        default:
            LOGERR("WARNING: option_time_field has invalid value %c 0x%02X - going by default m\n",
                option_time_field, option_time_field);
            option_time_field = 'm';
            time_value = ptr->ln_stat.st_mtim.tv_sec;
            break;
        };
    out_print_time(time_value);
}

inline void out_print_type(struct list_node *ptr) {
    char entry[16] = "";

    /* regular file, directory and symlinks are most common */
    if (S_ISREG(ptr->ln_stat.st_mode)) {
        sprintf(entry, "regular file");
    } else if (S_ISDIR(ptr->ln_stat.st_mode)) {
        sprintf(entry, "directory");
    } else if (S_ISLNK(ptr->ln_stat.st_mode)) {
        sprintf(entry, "symlink");
    } else if (S_ISBLK(ptr->ln_stat.st_mode)) {
        sprintf(entry, "block");
    } else if (S_ISCHR(ptr->ln_stat.st_mode)) {
        sprintf(entry, "char");
    } else if (S_ISFIFO(ptr->ln_stat.st_mode)) {
        sprintf(entry, "fifo");
    } else if (S_ISSOCK(ptr->ln_stat.st_mode)) {
        sprintf(entry, "socket");
    /* The following macros operate on the complete struct stat */
    } else if (S_TYPEISMQ(&(ptr->ln_stat))) {
        sprintf(entry, "message queue");
    } else if (S_TYPEISSEM(&(ptr->ln_stat))) {
        sprintf(entry, "semaphore");
    } else if (S_TYPEISSHM(&(ptr->ln_stat))) {
        sprintf(entry, "shared memory");
#if 0
    /* Although mentioned in the POSIX man page, not part of glibc */
    } else if (S_TYPEISTMO(&(ptr->ln_stat))) {
        sprintf(entry, "memory object");
#endif
    } else {
        sprintf(entry, "unidentified");
    }
    /* The ones longer than 12 characters are rare. */
    printf(" %-12s ", entry);
}
/* === END OF FORMATTING FUNCTIONS === */



/* The most simple default output, formatted output is planned */
void print_list(struct list_head *list) {
    struct list_head *lh = list;
    struct list_node *ptr;
    size_t total_size = 0;

    if (list == NULL) return;
    if (option_sort_reverse_order) {
        lh = create_list_sort_reversed(list);
        /* be tolerant */
        if (lh == NULL) {
            lh = list;
        }
    }

    ptr = lh->first;
    while (ptr != NULL) {
        out_print_size(ptr);
        out_print_time_by_option(ptr);
        out_print_fname(ptr);
        out_print_newline();

        /* Linux: Neither man stat(2) nor stat(3type) declare why struct stat field st_size
         * would get a negative value assigned. The type off_t masks __off_t or __off64_t
         * which themselves mask bits/types.h __SLONGWORD_TYPE on x86_64 that's long int.
         * Haven't checked libc/kernel code but regardless why, I assume that a negative
         * value would imply a corrupt filesystem.
         */
        total_size += (ptr->ln_stat.st_size>0) ? (unsigned long int)ptr->ln_stat.st_size : 0;
        ptr = ptr->next;
    }
    fputc_all_cols('=', stdout);
    printf("\nTotal size: %lu %s\n", ((total_size>1024) ? total_size/1024 : total_size),
            ((total_size >= 1024) ? "kB" : ""));

    if (lh != list) destroy_list(lh);
}


/* For now with a large walk around common format strings and prevention of attack vectors.
 * n - name
 * s - file size
 * T - type
 *
 * Time related
 * t - timestamp set by option_time_field
 * A - timestamp from atim.tv_sec
 * C - timestamp from ctim.tv_sec
 * M - timestamp from mtim.tv_sec
 */
void print_list_formatted(const char *format, struct list_head *list) {
    struct list_head *lh = list;
    struct list_node *ptr;
    size_t format_len = 0, i = 0;

    if (format == NULL || format[0] == '\0') {
        LOGERR("ERROR: No format string given");
        return;
    }

    if (list == NULL || list->first == NULL) {
        LOGERR("ERROR: No data to print.\n");
        return;
    }

    if (option_sort_reverse_order) {
        lh = create_list_sort_reversed(list);
        /* be tolerant */
        if (lh == NULL) {
            lh = list;
        }
    }

    /* Note: the maximum length needs to be adjusted if the strings
     * shall contain more complicated settings */
    format_len = strnlen(format, 80);

    ptr = lh->first;
    while (ptr != NULL) {
        for (i=0; i < format_len; i++) {
            switch (format[i]) {
                case 'n':
                    out_print_fname(ptr);
                    break;
                case 's':
                    out_print_size(ptr);
                    break;
                case 't':
                    out_print_time_by_option(ptr);
                    break;
                case 'A':
                    out_print_time(ptr->ln_stat.st_atim.tv_sec);
                    break;
                case 'C':
                    out_print_time(ptr->ln_stat.st_ctim.tv_sec);
                    break;
                case 'M':
                    out_print_time(ptr->ln_stat.st_mtim.tv_sec);
                    break;
                case 'T':
                    out_print_type(ptr);
                    break;
                case ' ': /* just ignore this without warning */
                    break;
                default:
                    LOGERR("WARNING: Invalid character 0x%02X ignoring it\n", format[i]);
                    break;
            };
        }
        out_print_newline();
        ptr = ptr->next;
    }
    if (lh != list) destroy_list(lh);
}