config.c

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (C) 2019 Daniel Borkmann <daniel@iogearbox.net> */

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

#include "l2md.h"

enum {
	STATE_NONE = 0,
	STATE_GENERAL,
	STATE_REPO,
	STATE_MAX,
};

static void config_dump(struct config *cfg)
{
	struct config_repo *repo;
	struct config_url *url;
	uint32_t i, j;

	if (!verbose_enabled)
		return;

	verbose("general.base = %s\n", cfg->general.base);
	verbose("general.maildir = %s\n", cfg->general.maildir);
	verbose("general.period = %u\n", cfg->general.period);

	repo_for_each(cfg, repo, i) {
		verbose("repos.%s.maildir = %s\n", repo->name, repo->maildir);
		verbose("repos.%s.initial_import = %u\n", repo->name, repo->initial_import);
		url_for_each(repo, url, j) {
			verbose("repos.%s.url = %s\n", repo->name, url->path);
			verbose("repos.%s.oid_maildir = %s\n",
				repo->name, url->oid_known ? url->oid_maildir :
				"[unknown]");
		}
	}
}

static void config_probe_oids(struct config *cfg)
{
	struct config_repo *repo;
	struct config_url *url;
	char path[PATH_MAX];
	uint32_t i, j;
	int ret;

	repo_for_each(cfg, repo, i) {
		url_for_each(repo, url, j) {
			repo_local_oid(cfg, repo, url, path, sizeof(path));
			ret = xread_file(path, url->oid_maildir,
					 sizeof(url->oid_maildir) - 1, false);
			if (!ret)
				url->oid_known = true;
		}
	}
}

static void config_set_basedir(struct config *cfg, const char *dir)
{
	wordexp_t p;

	wordexp(dir, &p, 0);
	dir = p.we_wordv[0];
	strlcpy(cfg->general.base, dir, sizeof(cfg->general.base));
	wordfree(&p);
}

static void config_set_maildir(struct config *cfg, const char *dir, bool root)
{
	struct config_repo *repo = repo_last(cfg);
	char *maildir = root ? cfg->general.maildir : repo->maildir;
	wordexp_t p;

	wordexp(dir, &p, 0);
	dir = p.we_wordv[0];
	strlcpy(maildir, dir, sizeof(repo->maildir));
	wordfree(&p);
}

static void config_set_initial_import(struct config *cfg, uint32_t limit)
{
	struct config_repo *repo = repo_last(cfg);

	repo->initial_import = limit;
	if (repo->initial_import > 0)
		repo->limit = true;
}

static void config_new_url(struct config *cfg, const char *git_url)
{
	struct config_repo *repo = repo_last(cfg);
	struct config_url *url;

	repo->urls_num++;
	repo->urls = xrealloc(repo->urls, sizeof(*repo->urls) *
			      repo->urls_num);
	url = url_last(repo);
	memset(url, 0, sizeof(*url));
	strlcpy(url->path, git_url, sizeof(url->path));
}

static void config_new_repo(struct config *cfg, const char *name)
{
	struct config_repo *repo;

	cfg->repos_num++;
	cfg->repos = xrealloc(cfg->repos, sizeof(*cfg->repos) *
			      cfg->repos_num);
	repo = repo_last(cfg);
	memset(repo, 0, sizeof(*repo));
	config_set_maildir(cfg, cfg->general.maildir, false);
	strlcpy(repo->name, name, sizeof(repo->name));
}

static void config_set_defaults(struct config *cfg, const char *homedir)
{
	char path[PATH_MAX];

	cfg->general.period = 60;

	slprintf(path, sizeof(path), "%s/.l2md", homedir);
	strlcpy(cfg->general.base, path, sizeof(cfg->general.base));

	slprintf(path, sizeof(path), "%s/maildir", cfg->general.base);
	strlcpy(cfg->general.maildir, path, sizeof(cfg->general.maildir));
}

void config_uninit(struct config *cfg)
{
	struct config_repo *repo;
	uint32_t i;

	repo_for_each(cfg, repo, i)
		xfree(repo->urls);
	xfree(cfg->repos);
	xfree(cfg);
}

struct config *config_init(int argc, char **argv)
{
	const char *homedir = getenv("HOME");
	char buff[1024], tmp[1024];
	char path[PATH_MAX];
	bool seen[STATE_MAX] = {};
	int state = STATE_NONE;
	struct config *cfg;
	FILE *fp;

	if (argc > 1) {
		if (argc == 2 && !strncmp(argv[1], "--verbose",
					  sizeof("--verbose")))
			verbose_enabled = true;
		else
			panic("Usage: %s [--verbose]\n", argv[0]);
	}

	if (!homedir)
		panic("Cannot retrieve $HOME from env!\n");

	slprintf(path, sizeof(path), "%s/.l2mdconfig", homedir);
	fp = fopen(path, "r");
	if (!fp)
		panic("Cannot open config %s: %s\n", tmp, strerror(errno));

	cfg = xzmalloc(sizeof(*cfg));
	config_set_defaults(cfg, homedir);

	while (fgets(buff, sizeof(buff), fp)) {
		uint32_t val;

		if (buff[0] == '#' || buff[0] == '\n')
			continue;

		seen[state] = true;
		switch (state) {
		case STATE_NONE:
		state_next:
			if (!strcmp(buff, "[general]\n")) {
				state = STATE_GENERAL;
			} else if (sscanf(buff, "[repo %[a-z0-9-]]\n",
					  tmp) == 1) {
				state = STATE_REPO;
				config_new_repo(cfg, tmp);
			} else {
				panic("Cannot parse: '%s'\n", buff);
			}
			break;

		case STATE_GENERAL:
			if (seen[STATE_REPO])
				panic("[general] config must be before [repo *] config");
			else if (sscanf(buff, "\tperiod = %u", &val) == 1)
				cfg->general.period = val;
			else if (sscanf(buff, "\tmaildir = %s", tmp) == 1)
				config_set_maildir(cfg, tmp, true);
			else if (sscanf(buff, "\tbase = %s", tmp) == 1)
				config_set_basedir(cfg, tmp);
			else
				goto state_next;
			break;

		case STATE_REPO:
			if (sscanf(buff, "\turl = %s", tmp) == 1)
				config_new_url(cfg, tmp);
			else if (sscanf(buff, "\tmaildir = %s", tmp) == 1)
				config_set_maildir(cfg, tmp, false);
			else if (sscanf(buff, "\tinitial_import = %u", &val) == 1)
				config_set_initial_import(cfg, val);
			else
				goto state_next;
			break;

		default:
			panic("Invalid parser state: %d\n", state);
		};
	}

	fclose(fp);

	config_probe_oids(cfg);
	config_dump(cfg);

	return cfg;
}