#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>

#include <macLib.h>
#include <epicsVersion.h>

#define EPICSVER EPICS_VERSION*10000+EPICS_REVISION*100+EPICS_MODIFICATION

#ifdef vxWorks
#include "asprintf.h"
#ifdef _WRS_VXWORKS_MAJOR
/* vxWorks 6+ */
#include <private/shellLibP.h>
#else
/* vxWorks 5 */
#include <shellLib.h>
#include "strdup.h"
#endif
#endif

#if defined (_WIN32)
#include "asprintf.h"
#endif

#if (EPICSVER<31400)
extern char** ppGlobalEnviron;
#define OSI_PATH_LIST_SEPARATOR ":"
extern volatile int interruptAccept;

#else
#include <osiFileName.h>
#include <iocsh.h>
#ifndef EPICS_VERSION_INT
epicsShareFunc int epicsShareAPI iocshCmd(const char *cmd);
#endif
#include <epicsExport.h>
#endif

#include "expr.h"
#include "require.h"

#define SAVEENV(var) do { old_##var = getenv(#var); if (old_##var) old_##var=strdup(old_##var); } while(0)
#define RESTOREENV(var) do { if(old_##var) { putenvprintf("%s=%s", #var, old_##var); free(old_##var); }} while(0)

int runScriptDebug=0;

int isAbsPath(const char* filename)
{
#ifdef _WIN32
    /* network path, e.g. "\\x03ma\gac-x03ma\Data1" */
    if (strncmp(filename, "\\\\", 2) == 0)
        return 1;
    /* driver letter, e.g. "C:\Temp" */
    else if (strlen(filename) > 3
            && isalpha(filename[0])
            && filename[1] == ':')
        return 1;
    else
        return 0;
#else
    return filename[0] == '/' ? 1 : 0;
#endif
}

int runScript(const char* filename, const char* args)
{
    MAC_HANDLE *mac = NULL;
    FILE* file = NULL;
    char* line_raw = NULL;
    char* line_exp = NULL;
    long line_raw_size = 256;
    long line_exp_size = line_raw_size;
    long len;
    char** pairs;
    int status = 0;
    char* old_MODULE = NULL;
    char* old_MODULE_DIR = NULL;

    if (!filename)
    {
        fprintf(stderr, "Usage: runScript filename [macro=value,...]\n");
        return -1;
    }

    if (macCreateHandle(&mac,(
#if (EPICSVER>=31501)
        const
#endif
        char*[]){ "", "environ", NULL, NULL }) != 0) goto error;
    macSuppressWarning(mac, 1);
#if (EPICSVER<31403)
    /* Have no environment macro substitution, thus load envionment explicitly */
#ifndef vxWorks
    /* In 3.14 before 3.14.3 we may have non-vxWorks without environment macro substitution */
    /* non-vxWorks systems have environ instead of ppGlobalEnviron */
    #define ppGlobalEnviron environ
#endif
#ifdef _WRS_VXWORKS_MAJOR
    /* VxWorks 6 bug: environment is not NULL terminated ! */
    /* There is a non-public counter 8 bytes after ppGlobalEnviron */
    char** endEnviron = ppGlobalEnviron+((unsigned int*)&ppGlobalEnviron)[2];
    if (runScriptDebug)
            printf("runScript: %u environment variables\n", ((unsigned int*)&ppGlobalEnviron)[2]);
    for (pairs = ppGlobalEnviron; pairs < endEnviron; pairs++)
#else
    for (pairs = ppGlobalEnviron; *pairs; pairs++)
#endif
    {
        char* var, *eq;
        if (runScriptDebug)
            printf("runScript: environ %s\n", *pairs);

        /* take a copy to replace '=' with null byte */
        if ((var = strdup(*pairs)) == NULL) goto error;
        eq = strchr(var, '=');
        if (eq)
        {
            *eq = 0;
            macPutValue(mac, var, eq+1);
        }
        free(var);
    }
#endif

    if ((line_exp = malloc(line_exp_size)) == NULL) goto error;
    if ((line_raw = malloc(line_raw_size)) == NULL) goto error;

#ifdef vxWorks
    /* expand macros (environment variables) in file name because vxWorks shell can't do it */
#if (EPICSVER<31400)
    /* 3.13 version of macExpandString is broken and may write more than allowed */
    while ((len = labs(macExpandString(mac, (char*)filename, line_exp,
            line_exp_size/2))) >= line_exp_size/2)
#else       
    while ((len = labs(macExpandString(mac, filename, line_exp,
            line_exp_size-1))) >= line_exp_size-2)
#endif
    {
        if (runScriptDebug)
            printf("runScript: grow expand buffer: len=%ld size=%ld\n", len, line_exp_size);
        free(line_exp);
        if ((line_exp = malloc(line_exp_size *= 2)) == NULL) goto error;
    }
    filename = line_exp;
#endif

    /* add args to macro definitions */
    if (args)
    {
        if (runScriptDebug)
            printf("runScript: macParseDefns \"%s\"\n", args);
        macParseDefns(mac, (char*)args, &pairs);
        macInstallMacros(mac, pairs);
        free(pairs);
    }

    if (isAbsPath(filename))
    {
        file = fopen(filename, "r");
    }
    else
    {
        const char* dirname;
        const char* end;
        char* fullname;
        const char* path = getenv("SCRIPT_PATH");
        int dirlen;

        for (dirname = path; dirname != NULL; dirname = end)
        {
            end = strchr(dirname, OSI_PATH_LIST_SEPARATOR[0]);
            if (end && end[1] == '/' && end[2] == '/')   /* "http://..." and friends */
                end = strchr(end+2, OSI_PATH_LIST_SEPARATOR[0]);
            if (end) dirlen = (int)(end++ - dirname);
            else dirlen = (int)strlen(dirname);
            if (dirlen == 0) continue; /* ignore empty path elements */
            if (dirname[dirlen-1] == '/') dirlen--;
            asprintf(&fullname, "%.*s/%s",
                dirlen, dirname, filename);
            if (runScriptDebug)
                printf("runScript: trying %s\n", fullname);
            file = fopen(fullname, "r");
            if (!file && (errno & 0xffff) != ENOENT) perror(fullname);
            free(fullname);
            if (file) break;
        }
    }
    if (file == NULL) { perror(filename); return errno; }

    /* save some environments variables */
    SAVEENV(MODULE);
    SAVEENV(MODULE_DIR);

    /* execute script line by line after expanding macros with arguments or environment */
    while (fgets(line_raw, line_raw_size, file))
    {
        char* line_start, *x;
        int fail_ok = 0;

        /* check if we have a line longer than the buffer size */
        while (line_raw[(len = (long)strlen(line_raw))-1] != '\n' && !feof(file))
        {
            if (runScriptDebug)
                    printf("runScript partial line: \"%s\"\n", line_raw);
            if ((line_raw = realloc(line_raw, line_raw_size *= 2)) == NULL) goto error;
            if (fgets(line_raw + len, line_raw_size - len, file) == NULL) break;
        }
        while (len > 0 && isspace((unsigned char)line_raw[len-1])) line_raw[--len] = 0; /* get rid of '\n' and friends */

        /* Remember state of macros in case environment variable gets expanded */
        /* This would otherwise "freeze" environment macros to the state of their first expansion */
        macPushScope(mac);

        if (runScriptDebug)
                printf("runScript raw line (%ld chars): '%s'\n", len, line_raw);
        /* expand and check the buffer size (different epics versions write different may number of bytes)*/
        while ((len = labs(macExpandString(mac, line_raw, line_exp,
#if (EPICSVER<31400)
        /* 3.13 version of macExpandString is broken and may write more than allowed */
                line_exp_size/2))) >= line_exp_size/2)
#else       
                line_exp_size-1))) >= line_exp_size-2)
#endif
        {
            if (runScriptDebug)
                printf("runScript: grow expand buffer: len=%ld size=%ld\n", len, line_exp_size);
            free(line_exp);
            if ((line_exp = malloc(line_exp_size *= 2)) == NULL) goto error;
        }
        if (runScriptDebug)
                printf("runScript expanded line (%ld chars): '%s'\n", len, line_exp);

        macPopScope(mac);

        line_start = line_exp;
        while (isspace((unsigned char)*line_start)) line_start++;
        if (line_start[0] != '#' || line_start[1] != '-')
            printf("%s\n", line_exp);
        if (line_start[0] == 0 || line_start[0] == '#') continue;

        /* find local variable assignments */
        if ((x = strpbrk(line_start, "=(, \t\n\r")) != NULL && *x=='=')
        {
            *x++ = 0;
            replaceExpressions(x, line_raw, line_raw_size);
            if (runScriptDebug)
                printf("runScript: assign %s=%s\n", line_start, line_raw);
            macPutValue(mac, line_start, line_raw);
            continue;
        }
        if (*line_start == '?') {
            fail_ok = 1;
            line_start++;
            while (isspace((unsigned char)*line_start)) line_start++;
        }
#ifdef _WRS_VXWORKS_MAJOR
        if (strlen(line_start) >= 255)
        {
            fprintf(stderr, "runScript: Line too long (>=255):\n%s\n", line_start);
            return -1;
        }
        else
        {
            SHELL_EVAL_VALUE result;
            status = shellInterpEvaluate(line_start, "C", &result);
        }
#elif defined(vxWorks)
        if (strlen(line_start) >= 120)
        {
            fprintf(stderr, "runScript: Line too long (>=120):\n%s\n", line_start);
            return -1;
        }
        status = execute(line_start);
#else
        status = iocshCmd(line_start);
#endif
        if (status != 0) {
            if (fail_ok)
                fprintf(stderr, "runScript: Error ignored\n");
            else {
                fprintf(stderr, "runScript: Error terminated script %s\n", filename);
                break;
            }
        }
    }
    goto end;
error:
    if (errno)
    {
        status = errno;
        perror("runScript");
    }
end:
    free(line_raw);
    free(line_exp);
    if (mac) macDeleteHandle(mac);
    if (file) fclose(file);

    /* restore environment */
    RESTOREENV(MODULE);
    RESTOREENV(MODULE_DIR);

    return status;
}

#if (EPICSVER>=31400)

epicsExportAddress(int, runScriptDebug);
epicsExportAddress(int, exprDebug);

static const iocshFuncDef runScriptDef = {
    "runScript", 2, (const iocshArg *[]) {
        &(iocshArg) { "filename", iocshArgString },
        &(iocshArg) { "substitutions", iocshArgString },
}};

static void runScriptFunc(const iocshArgBuf *args)
{
    runScript(args[0].sval, args[1].sval);
}

static void runScriptRegister(void)
{
    static int firstTime = 1;
    if (firstTime) {
        firstTime = 0;
        iocshRegister (&runScriptDef, runScriptFunc);
    }
}
epicsExportRegistrar(runScriptRegister);
#endif