// This file is under GNU General Public License 3.0

// see LICENSE.txt

#define _POSIX_C_SOURCE 200809L

#ifdef ANDROID

#ifndef __LP64__ 

#include <time64.h>

#endif

#endif

#include <time.h>

#include <string.h>

#include <stdlib.h>

#include <assert.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <fcntl.h>

#include <regex.h>

#include "platform_unix.h"

#define MAX_PATH 1024

#ifndef LOCAL_DB_FILENAME

#define LOCAL_DB_FILENAME ".pEp_management.db"

#endif

#define SYSTEM_DB_FILENAME "system.db"

#ifndef bool

#define bool int

#define true 1

#define false 0

#endif

#ifdef ANDROID

#include <uuid.h>

/* FIXME : timegm will miss when linking for x86_64 on android, when supported */

#ifndef __LP64__ 

time_t timegm(struct tm* const t) {

    static const time_t kTimeMax = ~(1L << (sizeof(time_t) * CHAR_BIT - 1));

    static const time_t kTimeMin = (1L << (sizeof(time_t) * CHAR_BIT - 1));

    time64_t result = timegm64(t);

    if (result < kTimeMin || result > kTimeMax)

        return -1;

    return result;

}

#endif

char *stpncpy(char *dst, const char *src, size_t n)

{

    if (n != 0) {

        char *d = dst;

        const char *s = src;

        dst = &dst[n];

        do {

            if ((*d++ = *s++) == 0) {

                dst = d - 1;

                /* NUL pad the remaining n-1 bytes */

                while (--n != 0)

                    *d++ = 0;

                break;

            }

        } while (--n != 0);

    }

    return (dst);

}

char *stpcpy(char *dst, const char *src)

{

    for (;; ++dst, ++src) {

        *dst = *src;

        if (*dst == 0)

            break;

    }

    return dst;

}

/*

long int random(void)

{

    static bool seeded = false;

    static unsigned short xsubi[3];

    if(!seeded)

    {

        const long long t = (long long)time(NULL);

        xsubi[0] = (unsigned short)t;

        xsubi[1] = (unsigned short)(t>>16);

        xsubi[2] = (unsigned short)(t>>32);

        seeded = true;

    }

    return nrand48(xsubi);

} */

const char *android_system_db(void)

{

    static char buffer[MAX_PATH];

    static bool done = false;

    if (!done) {

        char *tw_env;

        if(tw_env = getenv("TRUSTWORDS")){

            char *p = stpncpy(buffer, tw_env, MAX_PATH);

            ssize_t len = MAX_PATH - (p - buffer) - 2;

            if (len < strlen(SYSTEM_DB_FILENAME)) {

                assert(0);

                return NULL;

            }

            *p++ = '/';

            strncpy(p, SYSTEM_DB_FILENAME, len);

            done = true;

        }else{

            return NULL;

        }

    }

    return buffer;

}

void uuid_generate_random(pEpUUID out)

{

    uuid_t *uuid;

    uuid_rc_t rc_create;

    size_t size = sizeof(uuid_string_t);

    void *_out = out;

    if ((rc_create = uuid_create(&uuid)) != UUID_RC_OK ||

        uuid_make(uuid, UUID_MAKE_V1) != UUID_RC_OK ||

        uuid_export(uuid, UUID_FMT_BIN, &_out, &size) != UUID_RC_OK)

    {

        memset(out, 0, sizeof(pEpUUID));

    }

    if (rc_create == UUID_RC_OK)

    {

        uuid_destroy(uuid);

    }

}

void uuid_unparse_upper(pEpUUID uu, uuid_string_t out)

{

    uuid_t *uuid;

    uuid_rc_t rc_create;

    size_t size = sizeof(uuid_string_t);

    void *_out = out;

    if ((rc_create = uuid_create(&uuid)) != UUID_RC_OK ||

        uuid_import(uuid, UUID_FMT_BIN, uu, sizeof(pEpUUID)) != UUID_RC_OK ||

        uuid_export(uuid, UUID_FMT_STR, &_out, &size) != UUID_RC_OK)

    {

        memset(out, 0, sizeof(uuid_string_t));

    }

    else 

    {

        out[sizeof(uuid_string_t) - 1] = 0;

    }

    if (rc_create == UUID_RC_OK)

    {

        uuid_destroy(uuid);

    }

}

#endif

#if !defined(BSD) && !defined(__APPLE__)

size_t strlcpy(char* dst, const	char* src, size_t size) {

    size_t retval = strlen(src);

    size_t size_to_copy = (retval < size ? retval : size - 1);

    // strlcpy doc says src and dst not allowed to overlap, as

    // it's undefined. So this is acceptable:

    memcpy((void*)dst, (void*)src, size_to_copy); // no defined error return, but strcpy doesn't either

    dst[size_to_copy] = '\0';

    return retval;

}

size_t strlcat(char* dst, const	char* src, size_t size) {

    size_t start_len = strnlen(dst, size);

    if (start_len == size)

        return size; // no copy, no null termination in size bytes, according to spec

    size_t add_len = strlen(src);

    size_t retval = start_len + add_len;

    size_t size_to_copy = (retval < size ? add_len : (size - start_len) - 1);

    // strlcat doc says src and dst not allowed to overlap, as

    // it's undefined. So this is acceptable:

    memcpy((void*)(dst + start_len), (void*)src, size_to_copy); // no defined error return, but strcpy doesn't either

    dst[start_len + size_to_copy] = '\0';

    return retval;

}

#ifdef USE_NETPGP

// FIXME: This may cause problems - this is a quick compatibility fix for netpgp code

int regnexec(const regex_t* preg, const char* string,

             size_t len, size_t nmatch, regmatch_t pmatch[], int eflags) {

    return regexec(preg, string, nmatch, pmatch, eflags);

}

#endif

#endif

#ifdef NDEBUG

const char *unix_local_db(void)

#else

const char *unix_local_db(int reset)

#endif

{

    static char buffer[MAX_PATH];

    static bool done = false;

    #ifdef NDEBUG

    if (!done)

    #else

    if ((!done) || reset)

    #endif

    {

        char *home_env;

        if((home_env = getenv("HOME"))){

            char *p = stpncpy(buffer, home_env, MAX_PATH);

            ssize_t len = MAX_PATH - (p - buffer) - 2;

            if (len < strlen(LOCAL_DB_FILENAME)) {

                assert(0);

                return NULL;

            }

            *p++ = '/';

            strncpy(p, LOCAL_DB_FILENAME, len);

            done = true;

        }else{

            return NULL;

        }

    }

    return buffer;

}

static const char *gpg_conf_path = ".gnupg";

static const char *gpg_conf_name = "gpg.conf";

static const char *gpg_agent_conf_name = "gpg-agent.conf";

static const char *gpg_conf_empty = "# Created by pEpEngine\n";

#ifdef NDEBUG

static bool ensure_gpg_home(const char **conf, const char **home){

#else

static bool ensure_gpg_home(const char **conf, const char **home, int reset){

#endif    

    static char path[MAX_PATH];

    static char dirname[MAX_PATH];

    static bool done = false;

#ifdef NDEBUG

    if (!done) {

#else

    if (reset || !done) {

#endif        

        char *p;

        ssize_t len;

        char *gpg_home_env = getenv("GNUPGHOME");

        char *home_env = getenv("HOME");

        if(gpg_home_env){

            p = stpncpy(path, gpg_home_env, MAX_PATH);

            len = MAX_PATH - (p - path) - 2;

            if (len < strlen(gpg_conf_name))

            {

                assert(0);

                return false;

            }

        }else if(home_env){

            p = stpncpy(path, home_env, MAX_PATH);

            len = MAX_PATH - (p - path) - 3;

            if (len < strlen(gpg_conf_path) + strlen(gpg_conf_name))

            {

                assert(0);

                return false;

            }

            *p++ = '/';

            strncpy(p, gpg_conf_path, len);

            p += strlen(gpg_conf_path);

            len -= strlen(gpg_conf_path) - 1;

        }else{

            assert(0);

            return false;

        }

        strncpy(dirname, path, MAX_PATH);

        *p++ = '/';

        strncpy(p, gpg_conf_name, len);

        if(access(path, F_OK)){ 

            int fd;

            if(access(dirname, F_OK )) { 

                mkdir(dirname, S_IRUSR | S_IWUSR | S_IXUSR);

            }

            fd = open(path, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);

            if(fd>0) {

                ssize_t res;

                len = strlen(gpg_conf_empty);

                res = write(fd, gpg_conf_empty, len);

                close(fd);

                if(res < len) {

                    assert(0);

                    return false;

                }

            }

        }

        done = true;

    }

    if(conf) *conf=path;

    if(home) *home=dirname;

    return true;

}

#ifdef NDEBUG

static bool ensure_gpg_agent_conf(const char **agent_conf){

#else

static bool ensure_gpg_agent_conf(const char **agent_conf, int reset){    

#endif    

    static char agent_path[MAX_PATH];

    static bool done = false;

#ifdef NDEBUG

    if (!done) {

        const char *dirname;

        if (!ensure_gpg_home(NULL, &dirname)) /* Then dirname won't be set. */

            return false;

#else

    if (reset || !done) {

        const char *dirname;

        if (!ensure_gpg_home(NULL, &dirname, reset)) /* Then dirname won't be set. */

            return false;

#endif

        char *p = stpncpy(agent_path, dirname, MAX_PATH);

        ssize_t len = MAX_PATH - (p - agent_path) - 2;

        if (len < strlen(gpg_agent_conf_name))

        {

            assert(0);

            return false;

        }

        *p++ = '/';

        strncpy(p, gpg_agent_conf_name, len);

        if(access(agent_path, F_OK)){ 

            int fd;

            if(access(dirname, F_OK )) { 

                mkdir(dirname, S_IRUSR | S_IWUSR | S_IXUSR);

            }

            fd = open(agent_path, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);

            if(fd>0) {

                ssize_t res;

                len = strlen(gpg_conf_empty);

                res = write(fd, gpg_conf_empty, len);

                close(fd);

                if(res < len) {

                    assert(0);

                    return false;

                }

            }

        }

        done = true;

    }

    if(agent_conf) *agent_conf=agent_path;

    return true;

}

#ifdef NDEBUG

const char *gpg_conf(void)

{

    const char *conf;

    if(ensure_gpg_home(&conf, NULL))

        return conf;

    return NULL;

}

#else

const char *gpg_conf(int reset)

{

    const char *conf;

    if(ensure_gpg_home(&conf, NULL, reset))

        return conf;

    return NULL;

}

#endif

#ifdef NDEBUG

const char *gpg_home(void)

{

    const char *home;

    if(ensure_gpg_home(NULL, &home))

        return home;

    return NULL;

}

#else

const char *gpg_home(int reset)

{

    const char *home;

    if(ensure_gpg_home(NULL, &home, reset))

        return home;

    return NULL;

}

#endif

#ifdef NDEBUG

const char *gpg_agent_conf(void)

{

    const char *agent_conf;

    if(ensure_gpg_agent_conf(&agent_conf))

        return agent_conf;

    return NULL;

}

#else

const char *gpg_agent_conf(int reset)

{

    const char *agent_conf;

    if(ensure_gpg_agent_conf(&agent_conf, reset))

        return agent_conf;

    return NULL;

}

#endif