#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include "JavaScript_Env.h"

#include "PJS_Types.h"
#include "PJS_Common.h"
#include "PJS_Function.h"
#include "PJS_Context.h"
#include "PJS_Runtime.h"
#include "PJS_Class.h"

/* Global class, does nothing */
static JSClass global_class = {
    "global", 0,
    JS_PropertyStub,  JS_PropertyStub,  JS_PropertyStub,  JS_PropertyStub,
    JS_EnumerateStub, JS_ResolveStub,   JS_ConvertStub,   JS_FinalizeStub,
    JSCLASS_NO_OPTIONAL_MEMBERS
};

PJS_Function * PJS_GetFunctionByName(PJS_Context *cx, const char *name) {
    PJS_Function *function;

    function = cx->functions;

    while(function != NULL) {
        if(strcmp(PJS_GetFunctionName(function), name) == 0) {
            return function;
        }
        
        function = function->_next;
    }

    return NULL;
}

PJS_Class * 
PJS_GetClassByName(PJS_Context *cx, const char *name) {
    PJS_Class *cls = NULL;
    
    cls = cx->classes;
    
    while (cls != NULL) {
        if (strcmp(PJS_GetClassName(cls), name) == 0) {
            return cls;
        }
        
        cls = cls->_next;
    }
    
    return NULL;
}

PJS_Class *
PJS_GetClassByPackage(PJS_Context *cx, const char *pkg) {
    PJS_Class *cls = NULL;
    
    cls = cx->classes;

    while (cls != NULL) {
        if (cls->pkg != NULL && strcmp(PJS_GetClassPackage(cls), pkg) == 0) {
            return cls;
        }
        
        cls = cls->_next;
    }
    
    return NULL;
}

/*
  Create PJS_Context structure
*/
PJS_Context * PJS_CreateContext(PJS_Runtime *rt) {
    PJS_Context *pcx;
    JSObject *obj;

    Newz(1, pcx, 1, PJS_Context);
    if (pcx == NULL) {
        croak("Failed to allocate memory for PJS_Context");
    }
    
    /* 
        The 'stack size' param here isn't actually the stack size, it's
        the "chunk size of the stack pool--an obscure memory management
        tuning knob"
        
        http://groups.google.com/group/mozilla.dev.tech.js-engine/browse_thread/thread/be9f404b623acf39
    */
    
    pcx->cx = JS_NewContext(rt->rt, 8192);

    if(pcx->cx == NULL) {
        Safefree(pcx);
        croak("Failed to create JSContext");
    }

#ifdef JSOPTION_DONT_REPORT_UNCAUGHT
    JS_SetOptions(pcx->cx, JSOPTION_DONT_REPORT_UNCAUGHT);
#endif

    obj = JS_NewObject(pcx->cx, &global_class, NULL, NULL);
    if (JS_InitStandardClasses(pcx->cx, obj) == JS_FALSE) {
        PJS_DestroyContext(pcx);
        croak("Standard classes not loaded properly.");
    }

    /* Add context to context list */
    pcx->functions = NULL;
    pcx->classes = NULL;
    pcx->rt = rt;
    pcx->next = rt->list;
    rt->list = pcx;

    JS_SetContextPrivate(pcx->cx, (void *) pcx);

    return pcx;
}

/*
  Free memory occupied by PJS_Context structure
*/
void PJS_DestroyContext(PJS_Context *pcx) {
    PJS_Function *pfunc, *pfunc_next;
    PJS_Class *pcls, *pcls_next;

    if (pcx == NULL) {
        return;
    }
    
    pfunc = pcx->functions;
    
    /* Check if we have any bound functions */
    while (pfunc != NULL) {
        pfunc_next = pfunc->_next;
        PJS_DestroyFunction(pfunc);
        pfunc = pfunc_next;
    }

    pcls = pcx->classes;
    /* Check if we have any bound classes */
    while (pcls != NULL) {
        pcls_next = pcls->_next;
        PJS_free_class(pcls);
        pcls = pcls_next;
    }

    /* Destory context */
    JS_DestroyContext(pcx->cx);

    Safefree(pcx);
}

PJS_Function *
PJS_DefineFunction(PJS_Context *inContext, const char *functionName, SV *perlCallback) {
    PJS_Function *function;
    JSContext    *js_context = inContext->cx;
    
    if (PJS_GetFunctionByName(inContext, functionName) != NULL) {
        warn("Function named '%s' is already defined in the context");
        return NULL;
    }
    
    if ((function = PJS_CreateFunction(functionName, perlCallback)) == NULL) {
        return NULL;
    }
    
    /* Add the function to the javascript context */
    if (JS_DefineFunction(js_context, JS_GetGlobalObject(js_context), functionName, PJS_invoke_perl_function, 0, 0) == JS_FALSE) {
        warn("Failed to define function");
        PJS_DestroyFunction(function);
        return NULL;
    }

    /* Insert function in context linked list */
    function->_next = inContext->functions;
    inContext->functions = function;      

    return function;
}

/* Called by context when a branch occurs */
JSBool PJS_branch_handler(JSContext *cx, JSScript *script) {
    dSP;

    PJS_Context *pcx;
    SV *rv;
    I32 rc = 0;
    JSBool status = JS_TRUE;
    
    pcx = PJS_GET_CONTEXT(cx);

    if (pcx != NULL && pcx->branch_handler) {
        ENTER ;
        SAVETMPS ;

        PUSHMARK(SP);
        
        rc = perl_call_sv(SvRV(pcx->branch_handler), G_SCALAR | G_EVAL);

        SPAGAIN;

        rv = POPs;

        if (!SvTRUE(rv)) {
            status = JS_FALSE;
        }

        if (SvTRUE(ERRSV)) {
            sv_setsv(ERRSV, &PL_sv_undef);
            status = JS_FALSE;
        }
        
        PUTBACK;

        FREETMPS;
        LEAVE;
    }

    return status;
}

JSContext *
PJS_GetJSContext(PJS_Context *fromContext) {
    if (fromContext != NULL) {
        return fromContext->cx;
    }
    
    return NULL;
}