#define _GNU_SOURCE
#include "rcfile.h"

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

/* Suffixes appended to the resolved base directory to form the rc-file
 * path -- kept as two separate constants (rather than one shared tail)
 * since the XDG_CONFIG_HOME branch is already rooted at a "config home"
 * directory while the HOME fallback still needs the "/.config" segment. */
#define RCFILE_XDG_SUFFIX  "/xce_test/rc"
#define RCFILE_HOME_SUFFIX "/.config/xce_test/rc"

char* rcfile_resolve_path(void)
{
    const char* xdg_config_home = getenv("XDG_CONFIG_HOME");
    if (xdg_config_home && *xdg_config_home) {
        size_t len = strlen(xdg_config_home) + strlen(RCFILE_XDG_SUFFIX) + 1;
        char*  path = (char*)malloc(len);
        if (!path)
            return NULL;
        snprintf(path, len, "%s%s", xdg_config_home, RCFILE_XDG_SUFFIX);
        return path;
    }

    const char* home = getenv("HOME");
    if (home && *home) {
        size_t len = strlen(home) + strlen(RCFILE_HOME_SUFFIX) + 1;
        char*  path = (char*)malloc(len);
        if (!path)
            return NULL;
        snprintf(path, len, "%s%s", home, RCFILE_HOME_SUFFIX);
        return path;
    }

    return NULL;
}

int rcfile_load(const char* path, int (*runner)(char* line))
{
    if (!path)
        return 0;

    FILE* f = fopen(path, "r");
    if (!f) {
        if (errno == ENOENT)
            return 0; /* missing rc file: silent no-op success */
        fprintf(stderr, "xce_test: warning: could not open rc file %s: %s\n",
                path, strerror(errno));
        return 0; /* present but unreadable: non-fatal warning */
    }

    int     rc   = 0;
    char*   line = NULL;
    size_t  cap  = 0;
    ssize_t n;
    while ((n = getline(&line, &cap, f)) != -1) {
        if (n > 0 && line[n - 1] == '\n')
            line[n - 1] = '\0';
        rc = runner(line);
        if (rc != 0)
            break;
    }

    /* fopen() succeeds on a directory on this platform -- the failure only
     * surfaces on the first read (getline() returns -1 with errno==EISDIR
     * and ferror(f) set, feof(f) NOT set). Treat that the same as an open
     * failure: one non-fatal stderr warning, no runner calls attributed to
     * it (rc is still 0 here since no line was ever successfully read). */
    if (rc == 0 && ferror(f)) {
        fprintf(stderr, "xce_test: warning: could not read rc file %s: %s\n",
                path, strerror(errno));
    }

    free(line);
    fclose(f);
    return rc;
}