#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include <limits.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/fcntl.h>
#include <sys/stat.h>

#include <talloc/talloc.h>
#include <list/list.h>
#include <log/log.h>
#include <process/process.h>

#include "platform.h"

static const char *partition = "common";
static const char *sysparams_dir = "/sys/firmware/opal/sysparams/";

struct param {
	char			*name;
	char			*value;
	bool			modified;
	struct list_item	list;
};

struct platform_powerpc {
	struct list		params;
};

static const char *known_params[] = {
	"auto-boot?",
	"petitboot,network",
	"petitboot,timeout",
	"petitboot,bootdev",
	NULL,
};

#define to_platform_powerpc(p) \
	(struct platform_powerpc *)(p->platform_data)

/* a partition max a max size of 64k * 16bytes = 1M */
static const int max_partition_size = 64 * 1024 * 16;

static bool param_is_known(const char *param, unsigned int len)
{
	const char *known_param;
	unsigned int i;

	for (i = 0; known_params[i]; i++) {
		known_param = known_params[i];
		if (len == strlen(known_param) &&
				!strncmp(param, known_param, len))
			return true;
	}

	return false;
}

static int parse_nvram_params(struct platform_powerpc *platform,
		char *buf, int len)
{
	char *pos, *name, *value;
	unsigned int paramlen;
	int i, count;

	/* discard 2 header lines:
	 * "common" partiton"
	 * ------------------
	 */
	pos = buf;
	count = 0;

	for (i = 0; i < len; i++) {
		if (pos[i] == '\n')
			count++;
		if (count == 2)
			break;
	}

	if (i == len) {
		fprintf(stderr, "failure parsing nvram output\n");
		return -1;
	}

	for (pos = buf + i; pos < buf + len; pos += paramlen + 1) {
		unsigned int namelen;
		struct param *param;
		char *newline;

		newline = strchr(pos, '\n');
		if (!newline)
			break;

		*newline = '\0';

		paramlen = strlen(pos);

		name = pos;
		value = strchr(pos, '=');
		if (!value)
			continue;

		namelen = value - name;
		if (namelen == 0)
			continue;

		if (!param_is_known(name, namelen))
			continue;

		value++;

		param = talloc(platform, struct param);
		param->modified = false;
		param->name = talloc_strndup(platform, name, namelen);
		param->value = talloc_strdup(platform, value);
		list_add(&platform->params, &param->list);
	}

	return 0;
}

static int parse_nvram(struct platform_powerpc *platform)
{
	struct process *process;
	const char *argv[5];
	int rc;

	argv[0] = "nvram";
	argv[1] = "--print-config";
	argv[2] = "--partition";
	argv[3] = partition;
	argv[4] = NULL;

	process = process_create(platform);
	process->path = "nvram";
	process->argv = argv;
	process->keep_stdout = true;

	rc = process_run_sync(process);

	if (rc || !process_exit_ok(process)) {
		fprintf(stderr, "nvram process returned "
				"non-zero exit status\n");
		rc = -1;
	} else {
		rc = parse_nvram_params(platform, process->stdout_buf,
					    process->stdout_len);
	}

	process_release(process);
	return rc;
}

static int write_nvram(struct platform_powerpc *platform)
{
	struct process *process;
	struct param *param;
	const char *argv[6];
	int rc;

	argv[0] = "nvram";
	argv[1] = "--update-config";
	argv[2] = NULL;
	argv[3] = "--partition";
	argv[4] = partition;
	argv[5] = NULL;

	process = process_create(platform);
	process->path = "nvram";
	process->argv = argv;

	list_for_each_entry(&platform->params, param, list) {
		char *paramstr;

		if (!param->modified)
			continue;

		paramstr = talloc_asprintf(platform, "%s=%s",
				param->name, param->value);
		argv[2] = paramstr;

		rc = process_run_sync(process);

		talloc_free(paramstr);

		if (rc || !process_exit_ok(process)) {
			rc = -1;
			pb_log("nvram update process returned "
					"non-zero exit status\n");
			break;
		}
	}

	process_release(process);
	return rc;
}

static const char *get_param(struct platform_powerpc *platform,
		const char *name)
{
	struct param *param;

	list_for_each_entry(&platform->params, param, list)
		if (!strcmp(param->name, name))
			return param->value;
	return NULL;
}

static void set_param(struct platform_powerpc *platform, const char *name,
		const char *value)
{
	struct param *param;

	list_for_each_entry(&platform->params, param, list) {
		if (strcmp(param->name, name))
			continue;

		if (!strcmp(param->value, value))
			return;

		talloc_free(param->value);
		param->value = talloc_strdup(param, value);
		param->modified = true;
		return;
	}


	param = talloc(platform, struct param);
	param->modified = true;
	param->name = talloc_strdup(platform, name);
	param->value = talloc_strdup(platform, value);
	list_add(&platform->params, &param->list);
}

static int parse_hwaddr(struct interface_config *ifconf, char *str)
{
	int i;

	if (strlen(str) != strlen("00:00:00:00:00:00"))
		return -1;

	for (i = 0; i < HWADDR_SIZE; i++) {
		char byte[3], *endp;
		unsigned long x;

		byte[0] = str[i * 3 + 0];
		byte[1] = str[i * 3 + 1];
		byte[2] = '\0';

		x = strtoul(byte, &endp, 16);
		if (endp != byte + 2)
			return -1;

		ifconf->hwaddr[i] = x & 0xff;
	}

	return 0;
}

static int parse_one_interface_config(struct config *config,
		char *confstr)
{
	struct interface_config *ifconf;
	char *tok, *saveptr;

	ifconf = talloc_zero(config, struct interface_config);

	if (!confstr || !strlen(confstr))
		goto out_err;

	/* first token should be the mac address */
	tok = strtok_r(confstr, ",", &saveptr);
	if (!tok)
		goto out_err;

	if (parse_hwaddr(ifconf, tok))
		goto out_err;

	/* second token is the method */
	tok = strtok_r(NULL, ",", &saveptr);
	if (!tok || !strlen(tok) || !strcmp(tok, "ignore")) {
		ifconf->ignore = true;

	} else if (!strcmp(tok, "dhcp")) {
		ifconf->method = CONFIG_METHOD_DHCP;

	} else if (!strcmp(tok, "static")) {
		ifconf->method = CONFIG_METHOD_STATIC;

		/* ip/mask, [optional] gateway */
		tok = strtok_r(NULL, ",", &saveptr);
		if (!tok)
			goto out_err;
		ifconf->static_config.address =
			talloc_strdup(ifconf, tok);

		tok = strtok_r(NULL, ",", &saveptr);
		if (tok) {
			ifconf->static_config.gateway =
				talloc_strdup(ifconf, tok);
		}

	} else {
		pb_log("Unknown network configuration method %s\n", tok);
		goto out_err;
	}

	config->network.interfaces = talloc_realloc(config,
			config->network.interfaces,
			struct interface_config *,
			++config->network.n_interfaces);

	config->network.interfaces[config->network.n_interfaces - 1] = ifconf;

	return 0;
out_err:
	talloc_free(ifconf);
	return -1;
}

static int parse_one_dns_config(struct config *config,
		char *confstr)
{
	char *tok, *saveptr;

	for (tok = strtok_r(confstr, ",", &saveptr); tok;
			tok = strtok_r(NULL, ",", &saveptr)) {

		char *server = talloc_strdup(config, tok);

		config->network.dns_servers = talloc_realloc(config,
				config->network.dns_servers, const char *,
				++config->network.n_dns_servers);

		config->network.dns_servers[config->network.n_dns_servers - 1]
				= server;
	}

	return 0;
}

static void populate_network_config(struct platform_powerpc *platform,
		struct config *config)
{
	char *val, *saveptr = NULL;
	const char *cval;
	int i;

	cval = get_param(platform, "petitboot,network");
	if (!cval || !strlen(cval))
		return;

	val = talloc_strdup(config, cval);

	for (i = 0; ; i++) {
		char *tok;

		tok = strtok_r(i == 0 ? val : NULL, " ", &saveptr);
		if (!tok)
			break;

		if (!strncasecmp(tok, "dns,", strlen("dns,")))
			parse_one_dns_config(config, tok + strlen("dns,"));
		else
			parse_one_interface_config(config, tok);

	}

	talloc_free(val);
}

static void populate_bootdev_config(struct platform_powerpc *platform,
		struct config *config)

{
	const char *val;

	config->boot_device = NULL;

	val = get_param(platform, "petitboot,bootdev");
	if (!val || !strlen(val))
		return;

	if (!strncmp(val, "uuid:", strlen("uuid:"))) {
		config->boot_device = talloc_strdup(config,
						val + strlen("uuid:"));

	} else if (!strncmp(val, "mac:", strlen("mac:"))) {
		config->boot_device = talloc_strdup(config,
						val + strlen("mac:"));

	} else {
		pb_log("bootdev config is in an unknown format "
				"(expected uuid:... or mac:...)");
	}
}

static void populate_config(struct platform_powerpc *platform,
		struct config *config)
{
	const char *val;
	char *end;
	unsigned long timeout;

	/* if the "auto-boot?' property is present and "false", disable auto
	 * boot */
	val = get_param(platform, "auto-boot?");
	config->autoboot_enabled = !val || strcmp(val, "false");

	val = get_param(platform, "petitboot,timeout");
	if (val) {
		timeout = strtoul(val, &end, 10);
		if (end != val) {
			if (timeout >= INT_MAX)
				timeout = INT_MAX;
			config->autoboot_timeout_sec = (int)timeout;
		}
	}

	populate_network_config(platform, config);

	populate_bootdev_config(platform, config);
}

static char *iface_config_str(void *ctx, struct interface_config *config)
{
	char *str;

	/* todo: HWADDR size is hardcoded as 6, but we may need to handle
	 * different hardware address formats */
	str = talloc_asprintf(ctx, "%02x:%02x:%02x:%02x:%02x:%02x,",
			config->hwaddr[0], config->hwaddr[1],
			config->hwaddr[2], config->hwaddr[3],
			config->hwaddr[4], config->hwaddr[5]);

	if (config->ignore) {
		str = talloc_asprintf_append(str, "ignore");

	} else if (config->method == CONFIG_METHOD_DHCP) {
		str = talloc_asprintf_append(str, "dhcp");

	} else if (config->method == CONFIG_METHOD_STATIC) {
		str = talloc_asprintf_append(str, "static,%s%s%s",
				config->static_config.address,
				config->static_config.gateway ? "," : "",
				config->static_config.gateway ?: "");
	}
	return str;
}

static char *dns_config_str(void *ctx, const char **dns_servers, int n)
{
	char *str;
	int i;

	str = talloc_strdup(ctx, "dns,");
	for (i = 0; i < n; i++) {
		str = talloc_asprintf_append(str, "%s%s",
				i == 0 ? "" : ",",
				dns_servers[i]);
	}

	return str;
}

static void update_string_config(struct platform_powerpc *platform,
		const char *name, const char *value)
{
	const char *cur;

	cur = get_param(platform, name);

	/* don't set an empty parameter if it doesn't already exist */
	if (!cur && !strlen(value))
		return;

	set_param(platform, name, value);
}

static void update_network_config(struct platform_powerpc *platform,
	struct config *config)
{
	unsigned int i;
	char *val;

	val = talloc_strdup(platform, "");

	for (i = 0; i < config->network.n_interfaces; i++) {
		char *iface_str = iface_config_str(platform,
					config->network.interfaces[i]);
		val = talloc_asprintf_append(val, "%s%s",
				*val == '\0' ? "" : " ", iface_str);
		talloc_free(iface_str);
	}

	if (config->network.n_dns_servers) {
		char *dns_str = dns_config_str(platform,
						config->network.dns_servers,
						config->network.n_dns_servers);
		val = talloc_asprintf_append(val, "%s%s",
				*val == '\0' ? "" : " ", dns_str);
		talloc_free(dns_str);
	}

	update_string_config(platform, "petitboot,network", val);

	talloc_free(val);
}

static void update_bootdev_config(struct platform_powerpc *platform,
		struct config *config)
{
	char *val, *tmp = NULL;

	if (!config->boot_device)
		val = "";
	else
		tmp = val = talloc_asprintf(platform,
				"uuid:%s", config->boot_device);

	update_string_config(platform, "petitboot,bootdev", val);
	talloc_free(tmp);
}

static int update_config(struct platform_powerpc *platform,
		struct config *config, struct config *defaults)
{
	char *tmp = NULL;
	const char *val;

	if (config->autoboot_enabled == defaults->autoboot_enabled)
		val = "";
	else
		val = config->autoboot_enabled ? "true" : "false";
	update_string_config(platform, "auto-boot?", val);

	if (config->autoboot_timeout_sec == defaults->autoboot_timeout_sec)
		val = "";
	else
		val = tmp = talloc_asprintf(platform, "%d",
				config->autoboot_timeout_sec);

	update_string_config(platform, "petitboot,timeout", val);
	if (tmp)
		talloc_free(tmp);

	update_network_config(platform, config);

	update_bootdev_config(platform, config);

	return write_nvram(platform);
}

static void set_exclusive_devtype(struct config *config,
		enum device_type devtype)
{
	config->n_boot_priorities = 2;
	config->boot_priorities = talloc_realloc(config,
			config->boot_priorities, struct boot_priority,
			config->n_boot_priorities);
	config->boot_priorities[0].type = devtype;
	config->boot_priorities[0].priority = 0;
	config->boot_priorities[1].type = DEVICE_TYPE_ANY;
	config->boot_priorities[1].priority = -1;
}

/* bootdev options that we recognise */
enum ipmi_bootdev {
	IPMI_BOOTDEV_NONE = 0x00,
	IPMI_BOOTDEV_NETWORK = 0x01,
	IPMI_BOOTDEV_DISK = 0x2,
	IPMI_BOOTDEV_SAFE = 0x3,
	IPMI_BOOTDEV_CDROM = 0x5,
	IPMI_BOOTDEV_SETUP = 0x6,
};

static int read_bootdev_sysparam(const char *name, uint8_t *val)
{
	uint8_t buf[2];
	char path[50];
	int fd, rc;

	strcpy(path, sysparams_dir);
	assert(strlen(name) < sizeof(path) - strlen(path));
	strcat(path, name);

	fd = open(path, O_RDONLY);
	if (fd < 0) {
		pb_debug("powerpc: can't access sysparam %s\n",
				name);
		return -1;
	}

	rc = read(fd, buf, sizeof(buf));

	close(fd);

	/* bootdev definitions should only be one byte in size */
	if (rc != 1) {
		pb_debug("powerpc: sysparam %s read returned %d\n",
				name, rc);
		return -1;
	}

	pb_debug("powerpc: sysparam %s: 0x%02x\n", name, buf[0]);

	switch (buf[0]) {
	default:
		return -1;
	case IPMI_BOOTDEV_NONE:
	case IPMI_BOOTDEV_NETWORK:
	case IPMI_BOOTDEV_DISK:
	case IPMI_BOOTDEV_SAFE:
	case IPMI_BOOTDEV_CDROM:
	case IPMI_BOOTDEV_SETUP:
		*val = buf[0];
	}

	return 0;
}

static int write_bootdev_sysparam(const char *name, uint8_t val)
{
	char path[50];
	int fd, rc;

	strcpy(path, sysparams_dir);
	assert(strlen(name) < sizeof(path) - strlen(path));
	strcat(path, name);

	fd = open(path, O_WRONLY);
	if (fd < 0) {
		pb_debug("powerpc: can't access sysparam %s for writing\n",
				name);
		return -1;
	}

	for (;;) {
		errno = 0;
		rc = write(fd, &val, sizeof(val));
		if (rc == sizeof(val)) {
			rc = 0;
			break;
		}

		if (rc <= 0 && errno != EINTR) {
			pb_log("powerpc: error updating sysparam %s: %s",
					name, strerror(errno));
			rc = -1;
			break;
		}
	}

	close(fd);

	if (!rc)
		pb_debug("powerpc: set sysparam %s: 0x%02x\n", name, val);

	return rc;
}

static void parse_opal_sysparams(struct config *config)
{
	uint8_t next_bootdev, default_bootdev;
	bool next_valid, default_valid;
	int rc;

	rc = read_bootdev_sysparam("next-boot-device", &next_bootdev);
	next_valid = rc == 0;

	rc = read_bootdev_sysparam("default-boot-device", &default_bootdev);
	default_valid = rc == 0;

	/* nothing valid? no need to change the config */
	if (!next_valid && !default_valid)
		return;

	if (next_valid) {
		/* invalidate next-boot-device setting */
		write_bootdev_sysparam("next-boot-device", 0xff);
	} else {
		next_bootdev = default_bootdev;
	}

	switch (next_bootdev) {
	case IPMI_BOOTDEV_NONE:
		return;
	case IPMI_BOOTDEV_DISK:
		set_exclusive_devtype(config, DEVICE_TYPE_DISK);
		break;
	case IPMI_BOOTDEV_NETWORK:
		set_exclusive_devtype(config, DEVICE_TYPE_NETWORK);
		break;
	case IPMI_BOOTDEV_CDROM:
		set_exclusive_devtype(config, DEVICE_TYPE_OPTICAL);
		break;
	case IPMI_BOOTDEV_SETUP:
		config->autoboot_enabled = false;
		break;
	case IPMI_BOOTDEV_SAFE:
		config->autoboot_enabled = false;
		config->safe_mode = true;
		break;
	}
}

static int load_config(struct platform *p, struct config *config)
{
	struct platform_powerpc *platform = to_platform_powerpc(p);
	int rc;

	rc = parse_nvram(platform);
	if (rc)
		return rc;

	populate_config(platform, config);

	parse_opal_sysparams(config);

	return 0;
}

static int save_config(struct platform *p, struct config *config)
{
	struct platform_powerpc *platform = to_platform_powerpc(p);
	struct config *defaults;
	int rc;

	defaults = talloc_zero(platform, struct config);
	config_set_defaults(defaults);

	rc = update_config(platform, config, defaults);

	talloc_free(defaults);
	return rc;
}

static bool probe(struct platform *p, void *ctx)
{
	struct platform_powerpc *platform;
	struct stat statbuf;
	int rc;

	/* we need a device tree */
	rc = stat("/proc/device-tree", &statbuf);
	if (rc)
		return false;

	if (!S_ISDIR(statbuf.st_mode))
		return false;

	platform = talloc(ctx, struct platform_powerpc);
	list_init(&platform->params);

	p->platform_data = platform;
	return true;
}

static struct platform platform_powerpc = {
	.name		= "powerpc",
	.dhcp_arch_id	= 0x000e,
	.probe		= probe,
	.load_config	= load_config,
	.save_config	= save_config,
};

register_platform(platform_powerpc);