#include "cp.h"

uint32_t dst_mode = O_RDWR | O_CREAT;
uint32_t arg = 0;

void cp_real(int fd, const char *src, const char *dst)
{
    if ((arg & PARAM_L)) {
        if (arg & PARAM_V)
            printf("link %s -> %s\n", src, dst);
        link(src, dst);
    } else if ((arg & PARAM_S)) {
        if (arg & PARAM_V)
            printf("symlink %s -> %s\n", src, dst);
        symlink(src, dst);
    } else {
        if (arg & PARAM_V)
            printf("copydata %s -> %s\n", src, dst);
        struct stat src_statbuf;
        fstat(fd, &src_statbuf);
        int dstfd = open(dst, dst_mode, 0644);
        struct stat dst_statbuf;
        fstat(dstfd, &dst_statbuf);
        if (!dst_statbuf.st_size)
            ftruncate(dstfd, src_statbuf.st_size);
        char buf[100];
        int size;
        while ((size = read(fd, buf, sizeof(buf))) > 0)
            write(dstfd, buf, size);
    }
}

char buf1[512];
char buf2[512];

void cp(const char *src, const char *dst)
{
    arg |= PARAM_R;
    dst_mode |= O_TRUNC;
    arg |= PARAM_F;
    int srcfd = open(src, O_RDONLY);
    if (srcfd < 0) {
        MY_ERR("source file not exist");
        return;
    }
    struct stat src_statbuf;
    fstat(srcfd, &src_statbuf);
    int dstfd = open(dst, O_RDONLY);
    struct stat dst_statbuf;
    if (dstfd > 0)
        fstat(dstfd, &dst_statbuf);
    if (dstfd > 0 && !S_ISDIR(dst_statbuf.st_mode) && !(arg & PARAM_F)) {
        MY_ERR("dest file is exist");
        goto exit;
    }
    if (S_ISDIR(src_statbuf.st_mode)) {
        if (arg & PARAM_V)
            printf("process directory %s\n", src);
        if (!(arg & PARAM_R)) {
            MY_ERR("source file is directory");
            goto exit;
        }
        mkdir(dst, 0775);

        DIR *pDir;
        struct dirent *ent;
        pDir = opendir(src);
        while ((ent = readdir(pDir)) != NULL) {
            if (!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, ".."))
                continue;
            strcpy(buf1, src);
            strcat(buf1, "/");
            strcat(buf1, ent->d_name);
            strcpy(buf2, dst);
            strcat(buf2, "/");
            strcat(buf2, ent->d_name);
            cp(buf1, buf2);
        }
    } else {
        if (dstfd > 0 && S_ISDIR(dst_statbuf.st_mode)) {
            if (arg & PARAM_V)
                printf("process directory %s\n", dst);
            strcpy(buf1, dst);
            strcat(buf1, "/");
            get_name(buf2, src);
            strcat(buf1, buf2);
            cp(src, buf1);
        } else {
            cp_real(srcfd, src, dst);
        }
    }
exit:
    close(srcfd);
    close(dstfd);
}

void get_name(char *name, const char *pathname)
{
    if (pathname == NULL)
        return;
    size_t i = strlen(pathname);
    int j;
    for (j = i - 1; j >= 0; --j)
        if (pathname[j] == '/')
            break;
    strcpy(name, pathname + j + 1);
    name[i - j - 1] = '\0';
}

void my_err(const char *err_string, int line)
{
    //fprintf(stderr, "line: %d ", line);
    perror(err_string);
    exit(1);
}