Bagian 5: Logging dan Error Reporting

/* cli.c - Implementasi parsing argumen */
#include "cli.h"

#include <string.h>
#include <stdlib.h>

#define PROGRAM_NAME "mtool"
#define PROGRAM_VERSION "1.0.0"

void cli_print_help(FILE *out) {
    fprintf(out,
        "Penggunaan: %s [SUBCOMMAND] [OPTION]... [FILE]\n"
        "\n"
        "Alat pemrosesan teks baris perintah sederhana.\n"
        "\n"
        "Subperintah:\n"
        "  (none)             Baca stdin dan cetak jumlah baris.\n"
        "  help               Tampilkan pesan ini.\n"
        "  version            Tampilkan versi program.\n"
        "  count [FILE]       Hitung jumlah baris di FILE (atau stdin).\n"
        "  head [-n N] [FILE] Cetak N baris pertama (default 10).\n"
        "  tail [-n N] [FILE] Cetak N baris terakhir (default 10).\n"
        "  stats [FILE]       Statistik: jumlah baris, kata, karakter.\n"
        "  grep PATTERN [-i] [FILE]\n"
        "                     Cetak baris yang mengandung PATTERN.\n"
        "\n"
        "Opsi:\n"
        "  -n N               Jumlah baris untuk head/tail.\n"
        "  -i                 Case-insensitive untuk grep.\n"
        "  -v                 Verbose log ke stderr.\n"
        "  --help             Tampilkan pesan bantuan.\n"
        "  --version          Tampilkan versi.\n",
        PROGRAM_NAME);
}

void cli_print_version(FILE *out) {
    fprintf(out, "%s %s\n", PROGRAM_NAME, PROGRAM_VERSION);
}

/* Cek apakah string diawali tanda strip (option). */
static int is_option(const char *s) {
    return s != NULL && s[0] == '-' && s[1] != '\0';
}

int cli_parse(int argc, char *argv[], cli_args *out) {
    if (out == NULL) {
        return -1;
    }
    memset(out, 0, sizeof(*out));
    out->count = 10; /* default untuk head/tail */

    if (argc < 2) {
        out->subcommand = CLI_SUB_COUNT;
        return 0;
    }

    int i = 1;
    /* Deteksi subperintah pertama bila bukan option. */
    if (!is_option(argv[i])) {
        const char *cmd = argv[i];
        if (strcmp(cmd, "help") == 0 || strcmp(cmd, "--help") == 0) {
            out->subcommand = CLI_SUB_HELP;
            out->show_help = 1;
            return 0;
        }
        if (strcmp(cmd, "version") == 0 || strcmp(cmd, "--version") == 0) {
            out->subcommand = CLI_SUB_VERSION;
            out->show_version = 1;
            return 0;
        }
        if (strcmp(cmd, "count") == 0) {
            out->subcommand = CLI_SUB_COUNT;
        } else if (strcmp(cmd, "head") == 0) {
            out->subcommand = CLI_SUB_HEAD;
        } else if (strcmp(cmd, "tail") == 0) {
            out->subcommand = CLI_SUB_TAIL;
        } else if (strcmp(cmd, "stats") == 0) {
            out->subcommand = CLI_SUB_STATS;
        } else if (strcmp(cmd, "grep") == 0) {
            out->subcommand = CLI_SUB_GREP;
        } else if (cmd[0] == '-' && cmd[1] == '-') {
            /* long option tanpa subcommand */
            out->subcommand = CLI_SUB_COUNT;
        } else if (is_option(cmd)) {
            /* short option tanpa subcommand: anggap count */
            out->subcommand = CLI_SUB_COUNT;
        } else {
            /* Bukan subperintah yang dikenal, anggap sebagai path file. */
            out->subcommand = CLI_SUB_COUNT;
            out->file_path = cmd;
            i++;
            return 0;
        }
        i++;
    } else {
        out->subcommand = CLI_SUB_COUNT;
    }

    /* Khusus grep: argumen non-option pertama adalah PATTERN. */
    if (out->subcommand == CLI_SUB_GREP) {
        if (i >= argc) {
            return -1; /* grep butuh pattern */
        }
        out->pattern = argv[i++];
    }

    /* Iterasi sisa argumen. */
    while (i < argc) {
        const char *a = argv[i];
        if (strcmp(a, "-n") == 0) {
            if (i + 1 >= argc) {
                return -1;
            }
            out->count = (int)strtol(argv[++i], NULL, 10);
            if (out->count < 0) {
                return -1;
            }
            i++;
        } else if (strcmp(a, "-i") == 0) {
            out->ignore_case = 1;
            i++;
        } else if (strcmp(a, "-v") == 0) {
            out->verbose = 1;
            i++;
        } else if (strcmp(a, "--help") == 0) {
            out->show_help = 1;
            i++;
        } else if (strcmp(a, "--version") == 0) {
            out->show_version = 1;
            i++;
        } else if (is_option(a)) {
            return -1; /* option tidak dikenal */
        } else {
            /* Argumen non-option: file_path. */
            if (out->file_path == NULL) {
                out->file_path = a;
            } else {
                return -1; /* lebih dari satu file (tidak didukung) */
            }
            i++;
        }
    }
    return 0;
}

/* config.c - Implementasi loader file konfigurasi */
#include "config.h"

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>

void config_init(config *c) {
    if (c == NULL) {
        return;
    }
    c->count = 0;
}

static void strip(char *s) {
    /* Trim whitespace di kiri. */
    char *start = s;
    while (*start != '\0' && isspace((unsigned char)*start)) {
        start++;
    }
    if (start != s) {
        memmove(s, start, strlen(start) + 1);
    }
    /* Trim whitespace di kanan. */
    size_t len = strlen(s);
    while (len > 0 && isspace((unsigned char)s[len - 1])) {
        s[--len] = '\0';
    }
}

static void parse_line(char *line, config *c) {
    /* Lewati komentar dan baris kosong. */
    if (line[0] == '#' || line[0] == ';' || line[0] == '\0') {
        return;
    }
    /* Cari '=' pemisah. */
    char *eq = strchr(line, '=');
    if (eq == NULL) {
        return;
    }
    *eq = '\0';
    char *key = line;
    char *value = eq + 1;
    strip(key);
    strip(value);
    if (key[0] == '\0' || c->count >= CONFIG_ENTRIES_MAX) {
        return;
    }
    config_entry *e = &c->entries[c->count];
    strncpy(e->key, key, CONFIG_KEY_MAX - 1);
    e->key[CONFIG_KEY_MAX - 1] = '\0';
    strncpy(e->value, value, CONFIG_VALUE_MAX - 1);
    e->value[CONFIG_VALUE_MAX - 1] = '\0';
    c->count++;
}

int config_load(config *c, const char *path) {
    if (c == NULL || path == NULL) {
        return -1;
    }
    config_init(c);
    FILE *fp = fopen(path, "r");
    if (fp == NULL) {
        return -1;
    }
    char line[256];
    while (fgets(line, sizeof(line), fp) != NULL) {
        /* Hapus newline. */
        size_t len = strlen(line);
        while (len > 0 && (line[len - 1] == '\n' || line[len - 1] == '\r')) {
            line[--len] = '\0';
        }
        parse_line(line, c);
    }
    fclose(fp);
    return c->count;
}

const char *config_get(const config *c, const char *key) {
    if (c == NULL || key == NULL) {
        return NULL;
    }
    for (int i = 0; i < c->count; i++) {
        if (strcmp(c->entries[i].key, key) == 0) {
            return c->entries[i].value;
        }
    }
    return NULL;
}

int config_get_int(const config *c, const char *key, int default_value) {
    const char *v = config_get(c, key);
    if (v == NULL) {
        return default_value;
    }
    return (int)strtol(v, NULL, 10);
}

/* file_processor.c - Implementasi pemrosesan file */
#include "file_processor.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

FILE *file_open(const char *path, const char *mode) {
    if (path == NULL) {
        if (strcmp(mode, "r") == 0) {
            return stdin;
        }
        if (strcmp(mode, "w") == 0) {
            return stdout;
        }
        return NULL;
    }
    return fopen(path, mode);
}

static void close_file(FILE *fp, const char *path) {
    if (path != NULL && fp != NULL) {
        fclose(fp);
    }
    (void)fp;
}

/* Helper: duplikasi string (pengganti strdup agar portable C11 murni). */
static char *dup_str(const char *s) {
    size_t len = strlen(s) + 1;
    char *copy = malloc(len);
    if (copy != NULL) {
        memcpy(copy, s, len);
    }
    return copy;
}

/* Helper: cek apakah string `s` mengandung substring `pattern`
 * secara case-insensitive. */
static int contains_ci(const char *s, const char *pattern) {
    if (pattern[0] == '\0') {
        return 1;
    }
    for (const char *p = s; *p != '\0'; p++) {
        const char *si = p;
        const char *pi = pattern;
        while (*si != '\0' && *pi != '\0' &&
               tolower((unsigned char)*si) == tolower((unsigned char)*pi)) {
            si++;
            pi++;
        }
        if (*pi == '\0') {
            return 1;
        }
    }
    return 0;
}

int file_stats_compute(const char *path, file_stats *out) {
    if (out == NULL) {
        return -1;
    }
    out->lines = 0;
    out->words = 0;
    out->chars = 0;
    FILE *fp = file_open(path, "r");
    if (fp == NULL) {
        return -1;
    }
    int prev_was_space = 1;
    int c;
    while ((c = fgetc(fp)) != EOF) {
        out->chars++;
        if (c == '\n') {
            out->lines++;
            prev_was_space = 1;
        } else if (isspace(c)) {
            prev_was_space = 1;
        } else {
            if (prev_was_space) {
                out->words++;
            }
            prev_was_space = 0;
        }
    }
    /* Hitung baris terakhir bila tidak diakhiri newline. */
    if (out->chars > 0 && !prev_was_space && out->lines == 0) {
        out->lines = 1;
    }
    close_file(fp, path);
    return 0;
}

int file_head(const char *path, int n) {
    if (n < 0) {
        return -1;
    }
    FILE *fp = file_open(path, "r");
    if (fp == NULL) {
        return -1;
    }
    int printed = 0;
    char buf[4096];
    while (printed < n && fgets(buf, sizeof(buf), fp) != NULL) {
        fputs(buf, stdout);
        printed++;
    }
    close_file(fp, path);
    return printed;
}

int file_tail(const char *path, int n) {
    if (n <= 0) {
        return 0;
    }
    FILE *fp = file_open(path, "r");
    if (fp == NULL) {
        return -1;
    }
    /* Alokasikan buffer sirkular untuk N baris terakhir. */
    char **ring = calloc((size_t)n, sizeof(char *));
    if (ring == NULL) {
        close_file(fp, path);
        return -1;
    }
    int idx = 0;
    int filled = 0;
    char buf[4096];
    while (fgets(buf, sizeof(buf), fp) != NULL) {
        if (ring[idx] != NULL) {
            free(ring[idx]);
        }
        ring[idx] = dup_str(buf);
        idx = (idx + 1) % n;
        if (filled < n) {
            filled++;
        }
    }
    /* Cetak sesuai urutan kronologis. */
    int start = (filled < n) ? 0 : idx;
    for (int k = 0; k < filled; k++) {
        int pos = (start + k) % n;
        if (ring[pos] != NULL) {
            fputs(ring[pos], stdout);
            free(ring[pos]);
        }
    }
    free(ring);
    close_file(fp, path);
    return filled;
}

int file_grep(const char *path, const char *pattern, int ignore_case) {
    if (pattern == NULL) {
        return -1;
    }
    FILE *fp = file_open(path, "r");
    if (fp == NULL) {
        return -1;
    }
    int printed = 0;
    char buf[4096];
    while (fgets(buf, sizeof(buf), fp) != NULL) {
        int match;
        if (ignore_case) {
            match = contains_ci(buf, pattern);
        } else {
            match = (strstr(buf, pattern) != NULL);
        }
        if (match) {
            fputs(buf, stdout);
            printed++;
        }
    }
    close_file(fp, path);
    return printed;
}

/* logger.c - Implementasi logger */
#include "logger.h"

#include <stdarg.h>
#include <string.h>
#include <time.h>

static log_level g_min_level = LOG_INFO;
static FILE     *g_out        = NULL;

static const char *level_name(log_level l) {
    switch (l) {
        case LOG_DEBUG: return "DEBUG";
        case LOG_INFO:  return "INFO";
        case LOG_WARN:  return "WARN";
        case LOG_ERROR: return "ERROR";
        case LOG_OFF:   return "OFF";
        default:        return "?";
    }
}

void log_init(log_level min, FILE *out) {
    g_min_level = min;
    g_out = (out != NULL) ? out : stderr;
}

void log_write(log_level level, const char *file, int line,
               const char *fmt, ...) {
    if (level < g_min_level || g_out == NULL) {
        return;
    }
    /* Timestamp sederhana: detik sejak epoch. */
    time_t now = time(NULL);
    struct tm *tm_info = localtime(&now);
    char ts[20];
    strftime(ts, sizeof(ts), "%Y-%m-%d %H:%M:%S", tm_info);

    /* Ambil basename file agar log ringkas. */
    const char *slash = strrchr(file, '/');
    const char *base = (slash != NULL) ? slash + 1 : file;

    fprintf(g_out, "[%s] [%s] %s:%d ", ts, level_name(level), base, line);

    va_list ap;
    va_start(ap, fmt);
    vfprintf(g_out, fmt, ap);
    va_end(ap);

    fputc('\n', g_out);
    fflush(g_out);
}

/* main.c - Program utama command-line tool "mtool" */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "cli.h"
#include "config.h"
#include "file_processor.h"
#include "logger.h"

/* Konfigurasi default bila file config ada. */
static const char *CONFIG_FILE = ".mtoolrc";

static int run_subcommand(const cli_args *args) {
    file_stats stats;

    switch (args->subcommand) {
        case CLI_SUB_HELP:
            cli_print_help(stdout);
            return 0;
        case CLI_SUB_VERSION:
            cli_print_version(stdout);
            return 0;
        case CLI_SUB_COUNT: {
            if (args->file_path == NULL) {
                /* Hitung baris dari stdin. */
                int c;
                long count = 0;
                while ((c = fgetc(stdin)) != EOF) {
                    if (c == '\n') {
                        count++;
                    }
                }
                printf("%ld\n", count);
                return 0;
            }
            if (file_stats_compute(args->file_path, &stats) != 0) {
                LOG_ERROR("tidak bisa membuka file: %s", args->file_path);
                return 1;
            }
            printf("%ld %s\n", stats.lines, args->file_path);
            return 0;
        }
        case CLI_SUB_HEAD:
            if (file_head(args->file_path, args->count) < 0) {
                LOG_ERROR("head gagal");
                return 1;
            }
            return 0;
        case CLI_SUB_TAIL:
            if (file_tail(args->file_path, args->count) < 0) {
                LOG_ERROR("tail gagal");
                return 1;
            }
            return 0;
        case CLI_SUB_STATS:
            if (file_stats_compute(args->file_path, &stats) != 0) {
                LOG_ERROR("tidak bisa membuka file: %s",
                          args->file_path ? args->file_path : "stdin");
                return 1;
            }
            printf("%8ld baris  %8ld kata  %8ld karakter  %s\n",
                   stats.lines, stats.words, stats.chars,
                   args->file_path ? args->file_path : "-");
            return 0;
        case CLI_SUB_GREP:
            if (args->pattern == NULL) {
                fprintf(stderr, "grep butuh PATTERN\n");
                return 1;
            }
            if (file_grep(args->file_path, args->pattern,
                          args->ignore_case) < 0) {
                LOG_ERROR("grep gagal");
                return 1;
            }
            return 0;
        case CLI_SUB_NONE:
        default:
            cli_print_help(stderr);
            return 1;
    }
}

int main(int argc, char *argv[]) {
    /* Inisialisasi logger default: level INFO ke stderr. */
    log_init(LOG_INFO, stderr);

    /* Muat config opsional bila ada. */
    config cfg;
    config_init(&cfg);
    if (config_load(&cfg, CONFIG_FILE) > 0) {
        const char *lvl = config_get(&cfg, "log_level");
        if (lvl != NULL) {
            if (strcmp(lvl, "DEBUG") == 0) {
                log_init(LOG_DEBUG, stderr);
            } else if (strcmp(lvl, "WARN") == 0) {
                log_init(LOG_WARN, stderr);
            } else if (strcmp(lvl, "ERROR") == 0) {
                log_init(LOG_ERROR, stderr);
            }
        }
    }

    cli_args args;
    if (cli_parse(argc, argv, &args) != 0) {
        fprintf(stderr, "Argumen tidak valid. Jalankan '%s help'.\n",
                argv[0]);
        return 2;
    }

    if (args.verbose) {
        log_init(LOG_DEBUG, stderr);
    }

    if (args.show_help) {
        cli_print_help(stdout);
        return 0;
    }
    if (args.show_version) {
        cli_print_version(stdout);
        return 0;
    }

    LOG_DEBUG("subcommand=%d file=%s",
               (int)args.subcommand,
               args.file_path ? args.file_path : "(stdin)");

    return run_subcommand(&args);
}

/* tests.c - Unit test untuk CLI tool */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

#include "cli.h"
#include "config.h"
#include "file_processor.h"

static int tests_run = 0;
static int tests_pass = 0;

#define ASSERT(cond, msg) \
    do { \
        tests_run++; \
        if (cond) { \
            tests_pass++; \
        } else { \
            printf("FAIL: %s (line %d)\n", msg, __LINE__); \
        } \
    } while (0)

static void test_cli_parse_count(void) {
    char *argv[] = {"mtool", "count", "data.txt"};
    cli_args args;
    int rc = cli_parse(3, argv, &args);
    ASSERT(rc == 0, "count harus sukses");
    ASSERT(args.subcommand == CLI_SUB_COUNT, "subcommand = COUNT");
    ASSERT(args.file_path != NULL, "file_path = data.txt");
    ASSERT(strcmp(args.file_path, "data.txt") == 0, "file_path benar");
}

static void test_cli_parse_head_with_n(void) {
    char *argv[] = {"mtool", "head", "-n", "5", "data.txt"};
    cli_args args;
    int rc = cli_parse(5, argv, &args);
    ASSERT(rc == 0, "head -n 5 harus sukses");
    ASSERT(args.subcommand == CLI_SUB_HEAD, "subcommand = HEAD");
    ASSERT(args.count == 5, "count = 5");
}

static void test_cli_parse_grep(void) {
    char *argv[] = {"mtool", "grep", "hello", "-i", "data.txt"};
    cli_args args;
    int rc = cli_parse(5, argv, &args);
    ASSERT(rc == 0, "grep harus sukses");
    ASSERT(args.subcommand == CLI_SUB_GREP, "subcommand = GREP");
    ASSERT(strcmp(args.pattern, "hello") == 0, "pattern = hello");
    ASSERT(args.ignore_case == 1, "ignore_case = 1");
}

static void test_cli_parse_help_version(void) {
    char *argv1[] = {"mtool", "help"};
    cli_args args;
    ASSERT(cli_parse(2, argv1, &args) == 0, "help sukses");
    ASSERT(args.subcommand == CLI_SUB_HELP, "subcommand = HELP");

    char *argv2[] = {"mtool", "version"};
    ASSERT(cli_parse(2, argv2, &args) == 0, "version sukses");
    ASSERT(args.subcommand == CLI_SUB_VERSION, "subcommand = VERSION");

    char *argv3[] = {"mtool", "--help"};
    ASSERT(cli_parse(2, argv3, &args) == 0, "--help sukses");
    ASSERT(args.show_help == 1, "show_help = 1");
}

static void test_cli_parse_unknown_option(void) {
    char *argv[] = {"mtool", "head", "-Z"};
    cli_args args;
    int rc = cli_parse(3, argv, &args);
    ASSERT(rc == -1, "opsi tidak dikenal = error");
}

static void test_config_load(void) {
    const char *path = "/tmp/test_mtool.cfg";
    FILE *fp = fopen(path, "w");
    ASSERT(fp != NULL, "bisa membuat file config");
    fprintf(fp, "# komentar\n");
    fprintf(fp, "log_level = DEBUG\n");
    fprintf(fp, "default_count = 25\n");
    fprintf(fp, "; komentar titik koma\n");
    fprintf(fp, "name = mtool\n");
    fclose(fp);

    config c;
    int n = config_load(&c, path);
    ASSERT(n == 3, "harus ada 3 entri");

    const char *v = config_get(&c, "log_level");
    ASSERT(v != NULL && strcmp(v, "DEBUG") == 0, "log_level = DEBUG");

    int i = config_get_int(&c, "default_count", 10);
    ASSERT(i == 25, "default_count = 25");

    /* key tidak ada -> default */
    i = config_get_int(&c, "tidak_ada", 42);
    ASSERT(i == 42, "key tidak ada = default");
}

static void test_file_stats(void) {
    const char *path = "/tmp/test_mtool_data.txt";
    FILE *fp = fopen(path, "w");
    ASSERT(fp != NULL, "bisa membuat file data");
    fprintf(fp, "hello world\n");
    fprintf(fp, "second line here\n");
    fprintf(fp, "third\n");
    fclose(fp);

    file_stats s;
    int rc = file_stats_compute(path, &s);
    ASSERT(rc == 0, "stats harus sukses");
    ASSERT(s.lines == 3, "lines = 3");
    ASSERT(s.words == 6, "words = 6");
    ASSERT(s.chars > 0, "chars > 0");
}

static void test_file_head_tail(void) {
    const char *path = "/tmp/test_mtool_data.txt";
    /* File ini sudah dibuat di test sebelumnya. */

    /* Head 2 baris: kembalikan jumlah baris yang dicetak. */
    int n = file_head(path, 2);
    ASSERT(n == 2, "head harus cetak 2 baris");

    /* Head dengan n melebihi total baris: tetap OK, cetak semua. */
    n = file_head(path, 100);
    ASSERT(n == 3, "head 100 harus cetak 3 baris (semua)");

    n = file_tail(path, 1);
    ASSERT(n == 1, "tail 1 harus cetak 1 baris");

    n = file_tail(path, 100);
    ASSERT(n == 3, "tail 100 harus cetak 3 baris");
}

static void test_file_grep(void) {
    const char *path = "/tmp/test_mtool_data.txt";

    int n = file_grep(path, "line", 0);
    ASSERT(n == 1, "grep 'line' case-sensitive = 1 (second line here)");

    n = file_grep(path, "LINE", 0);
    ASSERT(n == 0, "grep 'LINE' case-sensitive = 0");

    n = file_grep(path, "LINE", 1);
    ASSERT(n == 1, "grep 'LINE' case-insensitive = 1");

    n = file_grep(path, "hello", 0);
    ASSERT(n == 1, "grep 'hello' = 1");
}

int main(void) {
    test_cli_parse_count();
    test_cli_parse_head_with_n();
    test_cli_parse_grep();
    test_cli_parse_help_version();
    test_cli_parse_unknown_option();
    test_config_load();
    test_file_stats();
    test_file_head_tail();
    test_file_grep();

    printf("\n=== Hasil Test ===\n");
    printf("Total : %d\n", tests_run);
    printf("Lulus : %d\n", tests_pass);
    printf("Gagal : %d\n", tests_run - tests_pass);
    return (tests_run == tests_pass) ? 0 : 1;
}