#define _POSIX_C_SOURCE 200809L

#include <string.h>

#include <stdlib.h>

#include <assert.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <fcntl.h>

#include "platform_unix.h"

#define MAX_PATH 1024

#define LOCAL_DB_FILENAME ".pEp_management.db"

#define SYSTEM_DB_FILENAME "system.db"

#ifndef bool

#define bool int

#define true 1

#define false 0

#endif

#ifdef ANDROID

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 unsigned short xsubi[3] = {'p', 'E', 'p'};

    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);

            size_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;

}

#endif

const char *unix_local_db(void)

{

    static char buffer[MAX_PATH];

    static bool done = false;

    if (!done) {

        char *home_env;

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

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

            size_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";

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

    static char path[MAX_PATH];

    static char dirname[MAX_PATH];

    static bool done = false;

    if (!done) {

        char *p;

        size_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) {

                write(fd, gpg_conf_empty, strlen(gpg_conf_empty));

                close(fd);

            }

        }

        done = true;

    }

    if(conf) *conf=path;

    if(home) *home=dirname;

    return true;

}

static bool ensure_gpg_agent_conf(const char **agent_conf){

    static char agent_path[MAX_PATH];

    static bool done = false;

    if (!done) {

        const char *dirname;

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

            return false;

        char *p;

        p = stpncpy(agent_path, dirname, MAX_PATH);

        size_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) {

                write(fd, gpg_conf_empty, strlen(gpg_conf_empty));

                close(fd);

            }

        }

        done = true;

    }

    if(agent_conf) *agent_conf=agent_path;

    return true;

}

const char *gpg_conf(void)

{

    const char *conf;

    if(ensure_gpg_home(&conf, NULL))

        return conf;

    return NULL;

}

const char *gpg_home(void)

{

    const char *home;

    if(ensure_gpg_home(NULL, &home))

        return home;

    return NULL;

}

const char *gpg_agent_conf(void)

{

    const char *agent_conf;

    if(ensure_gpg_agent_conf(&agent_conf))

        return agent_conf;

    return NULL;

}