/* lib9p/tests/test_server/main.c - Main entry point for test 9P server
 *
 * Copyright (C) 2024-2025  Luke T. Shumaker <lukeshu@lukeshu.com>
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */

#include <error.h>

#include <lib9p/srv.h>
#include <libcr/coroutine.h>
#include <libhw/generic/net.h>
#include <libhw/generic/alarmclock.h>
#include <libhw/host_alarmclock.h>
#include <libhw/host_net.h>
#include <libmisc/macro.h>
#include <util9p/static.h>

#include "static.h"

/* configuration **************************************************************/

#include "config.h"

#ifndef CONFIG_SRV9P_NUM_CONNS
	#error config.h must define CONFIG_SRV9P_NUM_CONNS
#endif

/* globals ********************************************************************/

static implements_lib9p_srv_file *get_root(struct lib9p_srv_ctx *, struct lib9p_s);

const char *hexdig = "0123456789abcdef";

struct {
	struct hostnet_tcp_listener     listeners[CONFIG_SRV9P_NUM_CONNS];
	struct lib9p_srv                srv;
} globals = {
	.srv = (struct lib9p_srv){
		.rootdir = get_root,
	},
};

/* api ************************************************************************/

struct api_file {
	implements_lib9p_srv_file;

	uint64_t pathnum;
};

static void api_free(implements_lib9p_srv_file *) {}
static uint32_t api_chio(implements_lib9p_srv_file *, struct lib9p_srv_ctx *, bool, bool, bool) { return 0; }

static void api_wstat(implements_lib9p_srv_file *, struct lib9p_srv_ctx *ctx, struct lib9p_stat) { lib9p_error(&ctx->basectx, LINUX_EROFS, "cannot wstat API file"); }
static void api_remove(implements_lib9p_srv_file *, struct lib9p_srv_ctx *ctx) { lib9p_error(&ctx->basectx, LINUX_EROFS, "cannot remove API file"); }

static struct lib9p_qid api_qid(implements_lib9p_srv_file *_self) {
	struct api_file *self = VCALL_SELF(struct api_file, implements_lib9p_srv_file, _self);
	assert(self);

	return (struct lib9p_qid){
		.type = LIB9P_QT_FILE,
		.vers = 1,
		.path = self->pathnum,
	};
}
static struct lib9p_stat api_stat(implements_lib9p_srv_file *_self, struct lib9p_srv_ctx *) {
	struct api_file *self = VCALL_SELF(struct api_file, implements_lib9p_srv_file, _self);
	assert(self);

	return (struct lib9p_stat){
		.kern_type                = 0,
		.kern_dev                 = 0,
		.file_qid                 = api_qid(self),
		.file_mode                = 0222,
		.file_atime               = 1728337905,
		.file_mtime               = 1728337904,
		.file_size                = 0,
		.file_name                = lib9p_str("shutdown"),
		.file_owner_uid           = lib9p_str("root"),
		.file_owner_gid           = lib9p_str("root"),
		.file_last_modified_uid   = lib9p_str("root"),
		.file_extension           = lib9p_str(NULL),
		.file_owner_n_uid         = 0,
		.file_owner_n_gid         = 0,
		.file_last_modified_n_uid = 0,
	};
}
static uint32_t api_pwrite(implements_lib9p_srv_file *, struct lib9p_srv_ctx *, void *, uint32_t byte_count, uint64_t) {
	if (byte_count == 0)
		return 0;
	for (int i = 0; i < CONFIG_SRV9P_NUM_CONNS; i++)
		VCALL(&globals.listeners[i], close);
	return byte_count;
}

static struct lib9p_srv_file_vtable api_file_vtable = {
	.free   = api_free,
	.qid    = api_qid,
	.chio   = api_chio,

	.stat   = api_stat,
	.wstat  = api_wstat,
	.remove = api_remove,

	.pread  = NULL,
	.pwrite = api_pwrite,
};

/* file tree ******************************************************************/

enum { PATH_BASE = __COUNTER__ };
#define PATH_COUNTER __COUNTER__ - PATH_BASE

#define STATIC_FILE(STRNAME, SYMNAME)                                             \
	((struct util9p_static_file){                                             \
		._util9p_static_common = {                                        \
			.vtable = &util9p_static_file_vtable,                     \
			                                                          \
			.u_name = "root", .u_num = 0, /* owner user */            \
			.g_name = "root", .g_num = 0, /* owner group */           \
			.m_name = "root", .m_num = 0, /* last-modified-by user */ \
			                                                          \
			.pathnum = PATH_COUNTER,                                  \
			.name    = STRNAME,                                       \
			.perm    = 0444,                                          \
			.atime   = 1728337905,                                    \
			.mtime   = 1728337904,                                    \
		},                                                                \
		.data_start            = _binary_static_##SYMNAME##_start,        \
		.data_end              = _binary_static_##SYMNAME##_end,          \
	})

#define STATIC_DIR(STRNAME, ...)                                                  \
	((struct util9p_static_dir){                                              \
		._util9p_static_common = {                                        \
			.vtable = &util9p_static_dir_vtable,                      \
			                                                          \
			.u_name = "root", .u_num = 0, /* owner user */            \
			.g_name = "root", .g_num = 0, /* owner group */           \
			.m_name = "root", .m_num = 0, /* last-modified-by user */ \
			                                                          \
			.pathnum = PATH_COUNTER,                                  \
			.name    = STRNAME,                                       \
			.perm    = 0555,                                          \
			.atime   = 1728337905,                                    \
			.mtime   = 1728337904,                                    \
		},                                                                \
		.members = { __VA_ARGS__ __VA_OPT__(,) NULL },                    \
	})

/* NB: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118814 */
static struct util9p_static_dir root =
	STATIC_DIR("",
	           &STATIC_DIR("Documentation",
	                      &STATIC_FILE("x", Documentation_x)),
	           &STATIC_FILE("README.md", README_md),
	           &((struct api_file){.vtable = &api_file_vtable, .pathnum = PATH_COUNTER}));

static implements_lib9p_srv_file *get_root(struct lib9p_srv_ctx *LM_UNUSED(ctx), struct lib9p_s LM_UNUSED(treename)) {
	return &root;
}

/* main ***********************************************************************/

static COROUTINE read_cr(void *_i) {
	int i = *((int *)_i);
	cr_begin();

	hostnet_tcp_listener_init(&globals.listeners[i], 9000);

	lib9p_srv_read_cr(&globals.srv, &globals.listeners[i]);

	cr_end();
}

static COROUTINE init_cr(void *) {
	cr_begin();

	sleep_for_ms(1);

	for (int i = 0; i < CONFIG_SRV9P_NUM_CONNS; i++) {
		char name[] = {'r', 'e', 'a', 'd', '-', hexdig[i], '\0'};
		if (!coroutine_add(name, read_cr, &i))
			error(1, 0, "coroutine_add(read_cr, &i)");
	}
	for (int i = 0; i < 2*CONFIG_SRV9P_NUM_CONNS; i++) {
		char name[] = {'w', 'r', 'i', 't', 'e', '-', hexdig[i], '\0'};
		if (!coroutine_add(name, lib9p_srv_write_cr, &globals.srv))
			error(1, 0, "coroutine_add(lib9p_srv_write_cr, &globals.srv)");
	}

	cr_exit();
}

int main() {
	struct hostclock clock_monotonic = {
		.vtable   = &hostclock_vtable,
		.clock_id = CLOCK_MONOTONIC,
	};
	bootclock = &clock_monotonic;
	coroutine_add("init", init_cr, NULL);
	coroutine_main();
	return 0;
}