// SPDX-License-Identifier: GPL-2.0-only
/*
 * (c) 2009 Arnaldo Carvalho de Melo <acme@redhat.com>
 */

#include "strlist.h"
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <linux/zalloc.h>

static
struct rb_node *strlist__node_new(struct rblist *rblist __maybe_unused, const void *entry)
{
        const char *s = entry;
        struct rb_node *rc = NULL;
        struct str_node *snode = malloc(sizeof(*snode));

        if (snode != NULL) {
                snode->s = strdup(s);
                if (snode->s == NULL)
                        goto out_delete;
                rc = &snode->rb_node;
        }

        return rc;

out_delete:
        free(snode);
        return NULL;
}

static void str_node__delete(struct str_node *snode)
{
        zfree((char **)&snode->s);
        free(snode);
}

static
void strlist__node_delete(struct rblist *rblist __maybe_unused, struct rb_node *rb_node)
{
        struct str_node *snode = container_of(rb_node, struct str_node, rb_node);

        str_node__delete(snode);
}

static int strlist__node_cmp(struct rb_node *rb_node, const void *entry)
{
        const char *str = entry;
        struct str_node *snode = container_of(rb_node, struct str_node, rb_node);

        return strcmp(snode->s, str);
}

int strlist__add(struct strlist *slist, const char *new_entry)
{
        return rblist__add_node(&slist->rblist, new_entry);
}

int strlist__load(struct strlist *slist, const char *filename)
{
        char entry[1024];
        int err;
        FILE *fp = fopen(filename, "r");

        if (fp == NULL)
                return -errno;

        while (fgets(entry, sizeof(entry), fp) != NULL) {
                const size_t len = strlen(entry);

                if (len == 0)
                        continue;
                entry[len - 1] = '\0';

                err = strlist__add(slist, entry);
                if (err != 0)
                        goto out;
        }

        err = 0;
out:
        fclose(fp);
        return err;
}

void strlist__remove(struct strlist *slist, struct str_node *snode)
{
        rblist__remove_node(&slist->rblist, &snode->rb_node);
}

struct str_node *strlist__find(struct strlist *slist, const char *entry)
{
        struct str_node *snode = NULL;
        struct rb_node *rb_node = rblist__find(&slist->rblist, entry);

        if (rb_node)
                snode = container_of(rb_node, struct str_node, rb_node);

        return snode;
}

static int strlist__parse_list_entry(struct strlist *slist, const char *s,
                                     const char *subst_dir)
{
        int err;
        char *subst = NULL;

        if (strncmp(s, "file://", 7) == 0)
                return strlist__load(slist, s + 7);

        if (subst_dir) {
                err = -ENOMEM;
                if (asprintf(&subst, "%s/%s", subst_dir, s) < 0)
                        goto out;

                if (access(subst, F_OK) == 0) {
                        err = strlist__load(slist, subst);
                        goto out;
                }

                if (slist->file_only) {
                        err = -ENOENT;
                        goto out;
                }
        }

        err = strlist__add(slist, s);
out:
        free(subst);
        return err;
}

static int strlist__parse_list(struct strlist *slist, const char *list, const char *subst_dir)
{
        char *sep, *s = strdup(list), *sdup = s;
        int err;

        if (s == NULL)
                return -ENOMEM;

        while ((sep = strchr(s, ',')) != NULL) {
                *sep = '\0';
                err = strlist__parse_list_entry(slist, s, subst_dir);
                if (err != 0)
                        return err;
                s = sep + 1;
        }

        err = *s ? strlist__parse_list_entry(slist, s, subst_dir) : 0;
        free(sdup);
        return err;
}

struct strlist *strlist__new(const char *list, const struct strlist_config *config)
{
        struct strlist *slist = malloc(sizeof(*slist));

        if (slist != NULL) {
                bool file_only = false;
                const char *dirname = NULL;

                if (config) {
                        dirname = config->dirname;
                        file_only = config->file_only;
                }

                rblist__init(&slist->rblist);
                slist->rblist.node_cmp    = strlist__node_cmp;
                slist->rblist.node_new    = strlist__node_new;
                slist->rblist.node_delete = strlist__node_delete;

                slist->file_only = file_only;

                if (list && strlist__parse_list(slist, list, dirname) != 0)
                        goto out_error;
        }

        return slist;
out_error:
        free(slist);
        return NULL;
}

void strlist__delete(struct strlist *slist)
{
        if (slist != NULL)
                rblist__delete(&slist->rblist);
}

struct str_node *strlist__entry(const struct strlist *slist, unsigned int idx)
{
        struct str_node *snode = NULL;
        struct rb_node *rb_node;

        rb_node = rblist__entry(&slist->rblist, idx);
        if (rb_node)
                snode = container_of(rb_node, struct str_node, rb_node);

        return snode;
}