#include "../perf.h"
#include "util.h"
#include "fs.h"
#include <sys/mman.h>
#ifdef HAVE_BACKTRACE_SUPPORT
#include <execinfo.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <byteswap.h>
#include <linux/kernel.h>

/*
 * XXX We need to find a better place for these things...
 */
unsigned int page_size;

bool test_attr__enabled;

bool perf_host  = true;
bool perf_guest = false;

char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";

void event_attr_init(struct perf_event_attr *attr)
{
        if (!perf_host)
                attr->exclude_host  = 1;
        if (!perf_guest)
                attr->exclude_guest = 1;
        /* to capture ABI version */
        attr->size = sizeof(*attr);
}

int mkdir_p(char *path, mode_t mode)
{
        struct stat st;
        int err;
        char *d = path;

        if (*d != '/')
                return -1;

        if (stat(path, &st) == 0)
                return 0;

        while (*++d == '/');

        while ((d = strchr(d, '/'))) {
                *d = '\0';
                err = stat(path, &st) && mkdir(path, mode);
                *d++ = '/';
                if (err)
                        return -1;
                while (*d == '/')
                        ++d;
        }
        return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
}

static int slow_copyfile(const char *from, const char *to, mode_t mode)
{
        int err = -1;
        char *line = NULL;
        size_t n;
        FILE *from_fp = fopen(from, "r"), *to_fp;
        mode_t old_umask;

        if (from_fp == NULL)
                goto out;

        old_umask = umask(mode ^ 0777);
        to_fp = fopen(to, "w");
        umask(old_umask);
        if (to_fp == NULL)
                goto out_fclose_from;

        while (getline(&line, &n, from_fp) > 0)
                if (fputs(line, to_fp) == EOF)
                        goto out_fclose_to;
        err = 0;
out_fclose_to:
        fclose(to_fp);
        free(line);
out_fclose_from:
        fclose(from_fp);
out:
        return err;
}

int copyfile_mode(const char *from, const char *to, mode_t mode)
{
        int fromfd, tofd;
        struct stat st;
        void *addr;
        int err = -1;

        if (stat(from, &st))
                goto out;

        if (st.st_size == 0) /* /proc? do it slowly... */
                return slow_copyfile(from, to, mode);

        fromfd = open(from, O_RDONLY);
        if (fromfd < 0)
                goto out;

        tofd = creat(to, mode);
        if (tofd < 0)
                goto out_close_from;

        addr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fromfd, 0);
        if (addr == MAP_FAILED)
                goto out_close_to;

        if (write(tofd, addr, st.st_size) == st.st_size)
                err = 0;

        munmap(addr, st.st_size);
out_close_to:
        close(tofd);
        if (err)
                unlink(to);
out_close_from:
        close(fromfd);
out:
        return err;
}

int copyfile(const char *from, const char *to)
{
        return copyfile_mode(from, to, 0755);
}

unsigned long convert_unit(unsigned long value, char *unit)
{
        *unit = ' ';

        if (value > 1000) {
                value /= 1000;
                *unit = 'K';
        }

        if (value > 1000) {
                value /= 1000;
                *unit = 'M';
        }

        if (value > 1000) {
                value /= 1000;
                *unit = 'G';
        }

        return value;
}

static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
{
        void *buf_start = buf;
        size_t left = n;

        while (left) {
                ssize_t ret = is_read ? read(fd, buf, left) :
                                        write(fd, buf, left);

                if (ret <= 0)
                        return ret;

                left -= ret;
                buf  += ret;
        }

        BUG_ON((size_t)(buf - buf_start) != n);
        return n;
}

/*
 * Read exactly 'n' bytes or return an error.
 */
ssize_t readn(int fd, void *buf, size_t n)
{
        return ion(true, fd, buf, n);
}

/*
 * Write exactly 'n' bytes or return an error.
 */
ssize_t writen(int fd, void *buf, size_t n)
{
        return ion(false, fd, buf, n);
}

size_t hex_width(u64 v)
{
        size_t n = 1;

        while ((v >>= 4))
                ++n;

        return n;
}

static int hex(char ch)
{
        if ((ch >= '0') && (ch <= '9'))
                return ch - '0';
        if ((ch >= 'a') && (ch <= 'f'))
                return ch - 'a' + 10;
        if ((ch >= 'A') && (ch <= 'F'))
                return ch - 'A' + 10;
        return -1;
}

/*
 * While we find nice hex chars, build a long_val.
 * Return number of chars processed.
 */
int hex2u64(const char *ptr, u64 *long_val)
{
        const char *p = ptr;
        *long_val = 0;

        while (*p) {
                const int hex_val = hex(*p);

                if (hex_val < 0)
                        break;

                *long_val = (*long_val << 4) | hex_val;
                p++;
        }

        return p - ptr;
}

/* Obtain a backtrace and print it to stdout. */
#ifdef HAVE_BACKTRACE_SUPPORT
void dump_stack(void)
{
        void *array[16];
        size_t size = backtrace(array, ARRAY_SIZE(array));
        char **strings = backtrace_symbols(array, size);
        size_t i;

        printf("Obtained %zd stack frames.\n", size);

        for (i = 0; i < size; i++)
                printf("%s\n", strings[i]);

        free(strings);
}
#else
void dump_stack(void) {}
#endif

void get_term_dimensions(struct winsize *ws)
{
        char *s = getenv("LINES");

        if (s != NULL) {
                ws->ws_row = atoi(s);
                s = getenv("COLUMNS");
                if (s != NULL) {
                        ws->ws_col = atoi(s);
                        if (ws->ws_row && ws->ws_col)
                                return;
                }
        }
#ifdef TIOCGWINSZ
        if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
            ws->ws_row && ws->ws_col)
                return;
#endif
        ws->ws_row = 25;
        ws->ws_col = 80;
}

static void set_tracing_events_path(const char *mountpoint)
{
        snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s",
                 mountpoint, "tracing/events");
}

const char *perf_debugfs_mount(const char *mountpoint)
{
        const char *mnt;

        mnt = debugfs_mount(mountpoint);
        if (!mnt)
                return NULL;

        set_tracing_events_path(mnt);

        return mnt;
}

void perf_debugfs_set_path(const char *mntpt)
{
        snprintf(debugfs_mountpoint, strlen(debugfs_mountpoint), "%s", mntpt);
        set_tracing_events_path(mntpt);
}

static const char *find_debugfs(void)
{
        const char *path = perf_debugfs_mount(NULL);

        if (!path)
                fprintf(stderr, "Your kernel does not support the debugfs filesystem");

        return path;
}

/*
 * Finds the path to the debugfs/tracing
 * Allocates the string and stores it.
 */
const char *find_tracing_dir(void)
{
        static char *tracing;
        static int tracing_found;
        const char *debugfs;

        if (tracing_found)
                return tracing;

        debugfs = find_debugfs();
        if (!debugfs)
                return NULL;

        tracing = malloc(strlen(debugfs) + 9);
        if (!tracing)
                return NULL;

        sprintf(tracing, "%s/tracing", debugfs);

        tracing_found = 1;
        return tracing;
}

char *get_tracing_file(const char *name)
{
        const char *tracing;
        char *file;

        tracing = find_tracing_dir();
        if (!tracing)
                return NULL;

        file = malloc(strlen(tracing) + strlen(name) + 2);
        if (!file)
                return NULL;

        sprintf(file, "%s/%s", tracing, name);
        return file;
}

void put_tracing_file(char *file)
{
        free(file);
}

int parse_nsec_time(const char *str, u64 *ptime)
{
        u64 time_sec, time_nsec;
        char *end;

        time_sec = strtoul(str, &end, 10);
        if (*end != '.' && *end != '\0')
                return -1;

        if (*end == '.') {
                int i;
                char nsec_buf[10];

                if (strlen(++end) > 9)
                        return -1;

                strncpy(nsec_buf, end, 9);
                nsec_buf[9] = '\0';

                /* make it nsec precision */
                for (i = strlen(nsec_buf); i < 9; i++)
                        nsec_buf[i] = '0';

                time_nsec = strtoul(nsec_buf, &end, 10);
                if (*end != '\0')
                        return -1;
        } else
                time_nsec = 0;

        *ptime = time_sec * NSEC_PER_SEC + time_nsec;
        return 0;
}

unsigned long parse_tag_value(const char *str, struct parse_tag *tags)
{
        struct parse_tag *i = tags;

        while (i->tag) {
                char *s;

                s = strchr(str, i->tag);
                if (s) {
                        unsigned long int value;
                        char *endptr;

                        value = strtoul(str, &endptr, 10);
                        if (s != endptr)
                                break;

                        if (value > ULONG_MAX / i->mult)
                                break;
                        value *= i->mult;
                        return value;
                }
                i++;
        }

        return (unsigned long) -1;
}

int filename__read_int(const char *filename, int *value)
{
        char line[64];
        int fd = open(filename, O_RDONLY), err = -1;

        if (fd < 0)
                return -1;

        if (read(fd, line, sizeof(line)) > 0) {
                *value = atoi(line);
                err = 0;
        }

        close(fd);
        return err;
}

int filename__read_str(const char *filename, char **buf, size_t *sizep)
{
        size_t size = 0, alloc_size = 0;
        void *bf = NULL, *nbf;
        int fd, n, err = 0;

        fd = open(filename, O_RDONLY);
        if (fd < 0)
                return -errno;

        do {
                if (size == alloc_size) {
                        alloc_size += BUFSIZ;
                        nbf = realloc(bf, alloc_size);
                        if (!nbf) {
                                err = -ENOMEM;
                                break;
                        }

                        bf = nbf;
                }

                n = read(fd, bf + size, alloc_size - size);
                if (n < 0) {
                        if (size) {
                                pr_warning("read failed %d: %s\n",
                                           errno, strerror(errno));
                                err = 0;
                        } else
                                err = -errno;

                        break;
                }

                size += n;
        } while (n > 0);

        if (!err) {
                *sizep = size;
                *buf   = bf;
        } else
                free(bf);

        close(fd);
        return err;
}

const char *get_filename_for_perf_kvm(void)
{
        const char *filename;

        if (perf_host && !perf_guest)
                filename = strdup("perf.data.host");
        else if (!perf_host && perf_guest)
                filename = strdup("perf.data.guest");
        else
                filename = strdup("perf.data.kvm");

        return filename;
}

int perf_event_paranoid(void)
{
        char path[PATH_MAX];
        const char *procfs = procfs__mountpoint();
        int value;

        if (!procfs)
                return INT_MAX;

        scnprintf(path, PATH_MAX, "%s/sys/kernel/perf_event_paranoid", procfs);

        if (filename__read_int(path, &value))
                return INT_MAX;

        return value;
}

void mem_bswap_32(void *src, int byte_size)
{
        u32 *m = src;
        while (byte_size > 0) {
                *m = bswap_32(*m);
                byte_size -= sizeof(u32);
                ++m;
        }
}

void mem_bswap_64(void *src, int byte_size)
{
        u64 *m = src;

        while (byte_size > 0) {
                *m = bswap_64(*m);
                byte_size -= sizeof(u64);
                ++m;
        }
}