/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2006-03-12     Bernard      first version
 * 2018-11-02     heyuanjie    fix complie error in iar
 */

#include <rtthread.h>
#include <rthw.h>
#include <dfs_file.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/statfs.h>

#ifndef RT_USING_DFS
    #error  "lwp need file system(RT_USING_DFS)"
#endif

#include "lwp.h"

#define DBG_TAG    "LWP"
#define DBG_LVL    DBG_WARNING
#include <rtdbg.h>

extern void lwp_user_entry(void *args, const void *text, void *data);

/**
 * RT-Thread light-weight process
 */
void lwp_set_kernel_sp(uint32_t *sp)
{
    struct rt_lwp *user_data;
    user_data = (struct rt_lwp *)rt_thread_self()->lwp;
    user_data->kernel_sp = sp;
}

uint32_t *lwp_get_kernel_sp(void)
{
    struct rt_lwp *user_data;
    user_data = (struct rt_lwp *)rt_thread_self()->lwp;

    return user_data->kernel_sp;
}

static int lwp_argscopy(struct rt_lwp *lwp, int argc, char **argv)
{
    int size = sizeof(int)*3; /* store argc, argv, NULL */
    int *args;
    char *str;
    char **new_argv;
    int i;
    int len;

    for (i = 0; i < argc; i ++)
    {
        size += (rt_strlen(argv[i]) + 1);
    }
    size  += (sizeof(int) * argc);

    args = (int*)rt_malloc(size);
    if (args == RT_NULL)
        return -1;

    str = (char*)((int)args + (argc + 3) * sizeof(int));
    new_argv = (char**)&args[2];
    args[0] = argc;
    args[1] = (int)new_argv;

    for (i = 0; i < argc; i ++)
    {
        len = rt_strlen(argv[i]) + 1;
        new_argv[i] = str;
        rt_memcpy(str, argv[i], len);
        str += len;
    }
    new_argv[i] = 0;
    lwp->args = args;

    return 0;
}

static int lwp_load(const char *filename, struct rt_lwp *lwp, uint8_t *load_addr, size_t addr_size)
{
    int fd;
    uint8_t *ptr;
    int result = RT_EOK;
    int nbytes;
    struct lwp_header header;
    struct lwp_chunk  chunk;

    /* check file name */
    RT_ASSERT(filename != RT_NULL);
    /* check lwp control block */
    RT_ASSERT(lwp != RT_NULL);

    if (load_addr != RT_NULL)
    {
        lwp->lwp_type = LWP_TYPE_FIX_ADDR;
        ptr = load_addr;
    }
    else
    {
        lwp->lwp_type = LWP_TYPE_DYN_ADDR;
        ptr = RT_NULL;
    }

    /* open lwp */
    fd = open(filename, 0, O_RDONLY);
    if (fd < 0)
    {
        dbg_log(DBG_ERROR, "open file:%s failed!\n", filename);
        result = -RT_ENOSYS;
        goto _exit;
    }

    /* read lwp header */
    nbytes = read(fd, &header, sizeof(struct lwp_header));
    if (nbytes != sizeof(struct lwp_header))
    {
        dbg_log(DBG_ERROR, "read lwp header return error size: %d!\n", nbytes);
        result = -RT_EIO;
        goto _exit;
    }

    /* check file header */
    if (header.magic != LWP_MAGIC)
    {
        dbg_log(DBG_ERROR, "erro header magic number: 0x%02X\n", header.magic);
        result = -RT_EINVAL;
        goto _exit;
    }

    /* read text chunk info */
    nbytes = read(fd, &chunk, sizeof(struct lwp_chunk));
    if (nbytes != sizeof(struct lwp_chunk))
    {
        dbg_log(DBG_ERROR, "read text chunk info failed!\n");
        result = -RT_EIO;
        goto _exit;
    }

    dbg_log(DBG_LOG, "chunk name: %s, total len %d, data %d, need space %d!\n",
            "text", /*chunk.name*/ chunk.total_len, chunk.data_len, chunk.data_len_space);

    /* load text */
    {
        lwp->text_size = RT_ALIGN(chunk.data_len_space, 4);
        if (load_addr)
            lwp->text_entry = ptr;
        else
        {
#ifdef RT_USING_CACHE
            lwp->text_entry = (rt_uint8_t *)rt_malloc_align(lwp->text_size, RT_CPU_CACHE_LINE_SZ);
#else
            lwp->text_entry = (rt_uint8_t *)rt_malloc(lwp->text_size);
#endif

            if (lwp->text_entry == RT_NULL)
            {
                dbg_log(DBG_ERROR, "alloc text memory faild!\n");
                result = -RT_ENOMEM;
                goto _exit;
            }
            else
            {
                dbg_log(DBG_LOG, "lwp text malloc : %p, size: %d!\n", lwp->text_entry, lwp->text_size);
            }
        }
        dbg_log(DBG_INFO, "load text %d  => (0x%08x, 0x%08x)\n", lwp->text_size, (uint32_t)lwp->text_entry, (uint32_t)lwp->text_entry + lwp->text_size);

        nbytes = read(fd, lwp->text_entry, chunk.data_len);
        if (nbytes != chunk.data_len)
        {
            dbg_log(DBG_ERROR, "read text region from file failed!\n");
            result = -RT_EIO;
            goto _exit;
        }
#ifdef RT_USING_CACHE
        else
        {
            rt_hw_cpu_dcache_ops(RT_HW_CACHE_FLUSH, lwp->text_entry, lwp->text_size);
            rt_hw_cpu_icache_ops(RT_HW_CACHE_INVALIDATE, lwp->text_entry, lwp->text_size);
        }
#endif

        if (ptr != RT_NULL) ptr += nbytes;

        /* skip text hole */
        if ((chunk.total_len - sizeof(struct lwp_chunk) - chunk.data_len))
        {
            dbg_log(DBG_LOG, "skip text hole %d!\n", (chunk.total_len - sizeof(struct lwp_chunk) - chunk.data_len));
            lseek(fd, (chunk.total_len - sizeof(struct lwp_chunk) - chunk.data_len), SEEK_CUR);
        }
    }

    /* load data */
    nbytes = read(fd, &chunk, sizeof(struct lwp_chunk));
    if (nbytes != sizeof(struct lwp_chunk))
    {
        dbg_log(DBG_ERROR, "read data chunk info failed!\n");
        result = -RT_EIO;
        goto _exit;
    }

    dbg_log(DBG_LOG, "chunk name: %s, total len %d, data %d, need space %d!\n",
            chunk.name, chunk.total_len, chunk.data_len, chunk.data_len_space);

    {
        lwp->data_size = RT_ALIGN(chunk.data_len_space, 4);
        if (load_addr)
            lwp->data = ptr;
        else
        {
            lwp->data = rt_malloc(lwp->data_size);
            if (lwp->data == RT_NULL)
            {
                dbg_log(DBG_ERROR, "alloc data memory faild!\n");
                result = -RT_ENOMEM;
                goto _exit;
            }
            else
            {
                dbg_log(DBG_LOG, "lwp data malloc : %p, size: %d!\n", lwp->data, lwp->data_size);
                rt_memset(lwp->data, 0, lwp->data_size);
            }
        }

        dbg_log(DBG_INFO, "load data %d => (0x%08x, 0x%08x)\n", lwp->data_size, (uint32_t)lwp->data, (uint32_t)lwp->data + lwp->data_size);
        nbytes = read(fd, lwp->data, chunk.data_len);
        if (nbytes != chunk.data_len)
        {
            dbg_log(DBG_ERROR, "read data region from file failed!\n");
            result = -RT_ERROR;
            goto _exit;
        }
    }

_exit:
    if (fd >= 0)
        close(fd);

    if (result != RT_EOK)
    {
        if (lwp->lwp_type == LWP_TYPE_DYN_ADDR)
        {
            dbg_log(DBG_ERROR, "lwp dynamic load faild, %d\n", result);
            if (lwp->text_entry)
            {
                dbg_log(DBG_LOG, "lwp text free: %p\n", lwp->text_entry);
#ifdef RT_USING_CACHE
                rt_free_align(lwp->text_entry);
#else
                rt_free(lwp->text_entry);
#endif
            }
            if (lwp->data)
            {
                dbg_log(DBG_LOG, "lwp data free: %p\n", lwp->data);
                rt_free(lwp->data);
            }
        }
    }

    return result;
}

static void lwp_cleanup(struct rt_thread *tid)
{
    struct rt_lwp *lwp;

    dbg_log(DBG_INFO, "thread: %s, stack_addr: %08X\n", tid->name, tid->stack_addr);

    lwp = (struct rt_lwp *)tid->lwp;

    if (lwp->lwp_type == LWP_TYPE_DYN_ADDR)
    {
        dbg_log(DBG_INFO, "dynamic lwp\n");
        if (lwp->text_entry)
        {
            dbg_log(DBG_LOG, "lwp text free: %p\n", lwp->text_entry);
#ifdef RT_USING_CACHE
            rt_free_align(lwp->text_entry);
#else
            rt_free(lwp->text_entry);
#endif
        }
        if (lwp->data)
        {
            dbg_log(DBG_LOG, "lwp data free: %p\n", lwp->data);
            rt_free(lwp->data);
        }
    }

    dbg_log(DBG_LOG, "lwp free memory pages\n");
    rt_lwp_mem_deinit(lwp);

    /* cleanup fd table */
    rt_free(lwp->fdt.fds);
    rt_free(lwp->args);

    dbg_log(DBG_LOG, "lwp free: %p\n", lwp);
    rt_free(lwp);

    /* TODO: cleanup fd table */
}

static void lwp_thread(void *parameter)
{
    rt_thread_t tid;
    struct rt_lwp *lwp;

    lwp = (struct rt_lwp *)parameter;
    rt_lwp_mem_init(lwp);
    tid = rt_thread_self();
    tid->lwp = lwp;
    tid->cleanup = lwp_cleanup;

    lwp_user_entry(lwp->args, lwp->text_entry, lwp->data);
}

struct rt_lwp *rt_lwp_self(void)
{
    return (struct rt_lwp *)rt_thread_self()->lwp;
}

int exec(char *filename, int argc, char **argv)
{
    struct rt_lwp *lwp;
    int result;

    if (filename == RT_NULL)
        return -RT_ERROR;

    lwp = (struct rt_lwp *)rt_malloc(sizeof(struct rt_lwp));
    if (lwp == RT_NULL)
    {
        dbg_log(DBG_ERROR, "lwp struct out of memory!\n");
        return -RT_ENOMEM;
    }
    dbg_log(DBG_INFO, "lwp malloc : %p, size: %d!\n", lwp, sizeof(struct rt_lwp));

    rt_memset(lwp, 0, sizeof(*lwp));
    if (lwp_argscopy(lwp, argc, argv) != 0)
    {
        rt_free(lwp);
        return -ENOMEM;
    }

    result = lwp_load(filename, lwp, RT_NULL, 0);
    if (result == RT_EOK)
    {
        rt_thread_t tid;

        tid = rt_thread_create("user", lwp_thread, (void *)lwp,
                               1024 * 4, 2, 200);
        if (tid != RT_NULL)
        {
            dbg_log(DBG_LOG, "lwp kernel => (0x%08x, 0x%08x)\n", (rt_uint32_t)tid->stack_addr, (rt_uint32_t)tid->stack_addr + tid->stack_size);
            rt_thread_startup(tid);
            return RT_EOK;
        }
        else
        {
#ifdef RT_USING_CACHE
            rt_free_align(lwp->text_entry);
#else
            rt_free(lwp->text_entry);
#endif
            rt_free(lwp->data);
        }
    }

    rt_free(lwp->args);
    rt_free(lwp);

    return -RT_ERROR;
}