index.c

#include "mvcs.h"

/* Read index file */
int read_index(index_entry_t **entries, int *count) {
    FILE *f = fopen(INDEX_FILE, "r");
    if (!f) {
        *entries = NULL;
        *count = 0;
        return 0;
    }
    
    index_entry_t *ent = malloc(sizeof(index_entry_t) * MAX_INDEX_ENTRIES);
    if (!ent) {
        fclose(f);
        return -1;
    }
    
    *count = 0;
    char line[MAX_PATH_LEN + HASH_HEX_SIZE + 20];
    
    while (fgets(line, sizeof(line), f) && *count < MAX_INDEX_ENTRIES) {
        char hash_hex[HASH_HEX_SIZE];
        int mode;
        char path[MAX_PATH_LEN];
        
        if (sscanf(line, "%64s %o %4095s", hash_hex, &mode, path) == 3) {
            hex_to_hash(hash_hex, ent[*count].hash);
            ent[*count].mode = mode;
            strncpy(ent[*count].path, path, MAX_PATH_LEN - 1);
            ent[*count].path[MAX_PATH_LEN - 1] = '\0';
            (*count)++;
        }
    }
    
    fclose(f);
    *entries = ent;
    return 0;
}

/* Write index file */
int write_index(index_entry_t *entries, int count) {
    FILE *f = fopen(INDEX_FILE, "w");
    if (!f) return -1;
    
    for (int i = 0; i < count; i++) {
        char hash_hex[HASH_HEX_SIZE];
        hash_to_hex(entries[i].hash, hash_hex);
        fprintf(f, "%s %o %s\n", hash_hex, entries[i].mode, entries[i].path);
    }
    
    fclose(f);
    return 0;
}

/* Add file to index */
int add_to_index(const char *path) {
    /* Check if file exists */
    if (!file_exists(path)) {
        fprintf(stderr, "File not found: %s\n", path);
        return -1;
    }
    
    if (is_directory(path)) {
        fprintf(stderr, "Cannot add directory (not implemented): %s\n", path);
        return -1;
    }
    
    /* Hash the file */
    unsigned char hash[HASH_SIZE];
    if (write_blob(path, hash) != 0) {
        fprintf(stderr, "Failed to hash file: %s\n", path);
        return -1;
    }
    
    /* Read current index */
    index_entry_t *entries;
    int count;
    if (read_index(&entries, &count) != 0) {
        return -1;
    }
    
    /* Check if file already in index */
    int found = -1;
    for (int i = 0; i < count; i++) {
        if (strcmp(entries[i].path, path) == 0) {
            found = i;
            break;
        }
    }
    
    /* Get file mode */
    struct stat st;
    if (stat(path, &st) != 0) {
        fprintf(stderr, "Failed to stat file: %s\n", path);
        free(entries);
        return -1;
    }
    int mode = st.st_mode & 0777;
    
    /* Update or add entry */
    if (found >= 0) {
        memcpy(entries[found].hash, hash, HASH_SIZE);
        entries[found].mode = mode;
    } else {
        if (count >= MAX_INDEX_ENTRIES) {
            fprintf(stderr, "Index full\n");
            if (entries) free(entries);
            return -1;
        }
        memcpy(entries[count].hash, hash, HASH_SIZE);
        entries[count].mode = mode;
        strncpy(entries[count].path, path, MAX_PATH_LEN - 1);
        entries[count].path[MAX_PATH_LEN - 1] = '\0';
        count++;
    }
    
    /* Write updated index */
    int ret = write_index(entries, count);
    free(entries);
    
    return ret;
}