//////////////////////////////////////////////////////////
//     WaS (c) grimore.org - 2012, License: GPLv3              //
// Please see: http://www.gnu.org/licenses/gpl.html     //
// for legal details, rights of fair usage and          //
// the disclaimer and warranty conditions.              //
//////////////////////////////////////////////////////////

integer _comChannel = 0;
vector oPos = ZERO_VECTOR;
vector sPos = ZERO_VECTOR;
integer tItra = 0;
integer fItra = 0;
list tail = [];
list food = [];
integer TRAIL = 1;

//pragma inline
processFood(integer fIdx) {
    if(fIdx == -1) return;
    if(llVecDist(llList2Vector(food, fIdx), llGetPos() + oPos) > .5) jump next;
    ++TRAIL;
    food = llListReplaceList(food, (list)"", fIdx, fIdx);
    generateFood(1);
    llRegionSay(_comChannel, "EAT," + (string)(fIdx+1));
@next;
    processFood(--fIdx);
}

generateFood(integer num) {
    if(num == 0) return;
    vector fPos = <sPos.x + llFrand(5)*llList2Float([-1, 1], (integer)llFrand(2)), sPos.y, sPos.z + llFrand(5)*llList2Float([-1, 1], (integer)llFrand(2))>;
    food += fPos;
    llRezObject("[K] Snake Food", fPos, ZERO_VECTOR, ZERO_ROTATION, ++fItra);
    generateFood(--num);  
}

default
{
    state_entry() {
        sPos = llGetPos();
        _comChannel = ((integer)("0x"+llGetSubString((string)llGetOwner(),-8,-1)) & 0x3FFFFFFF) ^ 0xBFFFFFFF;
        llSetLinkPrimitiveParamsFast(2, [PRIM_POSITION, ZERO_VECTOR]);
        llRegionSay(_comChannel, "CLR");
        generateFood(1+(integer)llFrand(10));
        llListen(_comChannel, "", "", "");
    }
    at_target(integer tnum, vector targetPos, vector ourPos) {
        llStopMoveToTarget();
    }
    listen(integer chan,string name,key id,string mes) {
        if(llGetOwnerKey(id) != llGetOwner()) return;
        if(mes == "UP") state up;
        if(mes == "DOWN") state down;
        if(mes == "LEFT") state left;
        if(mes == "RIGHT") state right;
    }
    changed(integer change) {
        if(change & CHANGED_OWNER) state cleanup;
    }
    on_rez(integer param) {
        state cleanup;
    }
}

state up {
    state_entry() {
        llListen(_comChannel, "", "", "");
        llSetTimerEvent(1);
    }
    listen(integer chan,string name,key id,string mes) {
        if(llGetOwnerKey(id) != llGetOwner()) return;
        if(mes == "UP") state up;
        if(mes == "DOWN") state down;
        if(mes == "LEFT") state left;
        if(mes == "RIGHT") state right;
    }
    timer() {
        processFood(llGetListLength(food)-1);
        if(llFabs(oPos.z + .5) > 5 || ~llListFindList(tail, (list)oPos)) {
            llOwnerSay("Game Over.");
            state cleanup;
        }
        llRegionSay(_comChannel, "DIE," + (string)(tItra-TRAIL));
        if(llGetListLength(tail) == TRAIL) tail = llDeleteSubList(tail, 0, 0);
        llSetLinkPrimitiveParams(2, [PRIM_POS_LOCAL, (oPos+=<0,0,.5>) / llGetRootRotation()]);
        llRezObject("[K] Snake Body", llGetPos() + oPos - <0,0,.5>, ZERO_VECTOR, ZERO_ROTATION, tItra++);
        tail += oPos-<0,0,.5>;
    }
}
state down {
    state_entry() {
        llListen(_comChannel, "", "", "");
        llSetTimerEvent(1);
    }
    listen(integer chan,string name,key id,string mes) {
        if(llGetOwnerKey(id) != llGetOwner()) return;
        if(mes == "UP") state up;
        if(mes == "DOWN") state down;
        if(mes == "LEFT") state left;
        if(mes == "RIGHT") state right;
    }
    timer() {
        processFood(llGetListLength(food)-1);
        if(llFabs(oPos.z - .5) > 5 || ~llListFindList(tail, (list)oPos)) {
            llOwnerSay("Game Over.");
            state cleanup;
        }
        llRegionSay(_comChannel, "DIE," + (string)(tItra-TRAIL));
        if(llGetListLength(tail) == TRAIL) tail = llDeleteSubList(tail, 0, 0);
        llSetLinkPrimitiveParams(2, [PRIM_POS_LOCAL, (oPos-=<0,0,.5>) / llGetRootRotation()]);
        llRezObject("[K] Snake Body", llGetPos() + oPos + <0,0,.5>, ZERO_VECTOR, ZERO_ROTATION, tItra++);
        tail += oPos+<0,0,.5>;
    }
}
state left {
    state_entry() {
        llListen(_comChannel, "", "", "");
        llSetTimerEvent(1);
    }
    listen(integer chan,string name,key id,string mes) {
        if(llGetOwnerKey(id) != llGetOwner()) return;
        if(mes == "UP") state up;
        if(mes == "DOWN") state down;
        if(mes == "LEFT") state left;
        if(mes == "RIGHT") state right;
    }
    timer() {
        processFood(llGetListLength(food)-1);
        if(llFabs(oPos.x - .5) > 5 || ~llListFindList(tail, (list)oPos)) {
            llOwnerSay("Game Over.");
            state cleanup;
        }
        llRegionSay(_comChannel, "DIE," + (string)(tItra-TRAIL));
        if(llGetListLength(tail) == TRAIL) tail = llDeleteSubList(tail, 0, 0);
        llSetLinkPrimitiveParams(2, [PRIM_POS_LOCAL, (oPos-=<.5,0,0>) / llGetRootRotation()]);
        llRezObject("[K] Snake Body", llGetPos() + oPos + <.5,0,0>, ZERO_VECTOR, ZERO_ROTATION, tItra++);
        tail += oPos+<.5,0,0>;
    }
}
state right {
    state_entry() {
        llListen(_comChannel, "", "", "");
        llSetTimerEvent(1);
    }
    listen(integer chan,string name,key id,string mes) {
        if(llGetOwnerKey(id) != llGetOwner()) return;
        if(mes == "UP") state up;
        if(mes == "DOWN") state down;
        if(mes == "LEFT") state left;
        if(mes == "RIGHT") state right;
    }
    timer() {
        processFood(llGetListLength(food)-1);
        if(llFabs(oPos.x + .5) > 5 || ~llListFindList(tail, (list)oPos)) {
            llOwnerSay("Game Over.");
            state cleanup;
        }
        llRegionSay(_comChannel, "DIE," + (string)(tItra-TRAIL));
        if(llGetListLength(tail) == TRAIL) tail = llDeleteSubList(tail, 0, 0);
        llSetLinkPrimitiveParams(2, [PRIM_POS_LOCAL, (oPos+=<.5,0,0>) / llGetRootRotation()]);
        llRezObject("[K] Snake Body", llGetPos() + oPos - <.5,0,0>, ZERO_VECTOR, ZERO_ROTATION, tItra++);
        tail += oPos-<.5,0,0>;
    }
}

state cleanup {
    state_entry() {
        llRegionSay(_comChannel, "CLR");
        llResetScript();
    }
}