#include <setjmp.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "Check.h"
#include "Compiler.h"
#include "DataType.h"
#include "tokenizer/Tokenizer.h"
#include "utils/Functions.h"
#include "utils/Variables.h"
#include "vm/Operation.h"

static Error* error = NULL;
static ByteCode* code;
static int16 line = 1;
static const char* path = NULL;

static jmp_buf errorJump;

#define RETURN_BUFFER 16
#define BREAK_BUFFER 32

#define DT_OPERATION(op)                                                       \
    case RDT_INT: cAddOperation(OP_##op##_INT); break;                         \
    case RDT_FLOAT: cAddOperation(OP_##op##_FLOAT); break;

typedef DataType (*Parser)(void);

static bool onLine = false;

static Variables vars;
static Variables globalVars;
static Functions functions;
static Functions functionQueue;
static Structs structs;

static int returns[RETURN_BUFFER];
static int returnIndex = 0;
static int hasReturn = 0;
static DataType returnType;

static int breaks[BREAK_BUFFER];
static int breakIndex = 0;
static int forWhileStack = 0;
static int continueAt = 0;

typedef struct {
    const char* name;
    Operation intOp;
    Operation floatOp;
    Operation pointerOp;
    char padding[sizeof(Operation)];
} TypedOp;

#define TYPE_OP(NAME, FLOAT, POINTER, text)                                    \
    static const TypedOp TYPED_##NAME = {                                      \
        text, OP_##NAME##_INT, OP_##FLOAT, OP_##POINTER, {0}};
TYPE_OP(MUL, MUL_FLOAT, NOTHING, "*")
TYPE_OP(DIV, DIV_FLOAT, NOTHING, "/")
TYPE_OP(MOD, NOTHING, NOTHING, "%")
TYPE_OP(ADD, ADD_FLOAT, NOTHING, "+")
TYPE_OP(SUB, SUB_FLOAT, NOTHING, "-")
TYPE_OP(LESS, LESS_FLOAT, NOTHING, "<")
TYPE_OP(LESS_EQUAL, LESS_EQUAL_FLOAT, NOTHING, "<=")
TYPE_OP(GREATER, GREATER_FLOAT, NOTHING, ">")
TYPE_OP(GREATER_EQUAL, GREATER_EQUAL_FLOAT, NOTHING, ">=")
TYPE_OP(EQUAL, EQUAL_FLOAT, EQUAL_POINTER, "==")
TYPE_OP(NOT_EQUAL, NOT_EQUAL_FLOAT, NOT_EQUAL_POINTER, "!=")
TYPE_OP(BIT_OR, NOTHING, NOTHING, "|")
TYPE_OP(BIT_XOR, NOTHING, NOTHING, "^")
TYPE_OP(BIT_AND, NOTHING, NOTHING, "&")
TYPE_OP(LEFT_SHIFT, NOTHING, NOTHING, "<<")
TYPE_OP(RIGHT_SHIFT, NOTHING, NOTHING, ">>")

static check_format(2, 3) void cError(int codeLine, const char* format, ...) {
    va_list args;
    va_start(args, format);
    eInitErrorV(error, path, line, codeLine, format, args);
    va_end(args);
    longjmp(errorJump, 0);
}

static const char* cGetName(DataType dt) {
    return dtGetName(&structs, dt);
}

static void cInvalidOperation(int codeLine, DataType a, DataType b,
                              const char* op) {
    cError(codeLine, "invalid operation: %s %s %s", cGetName(a), op,
           cGetName(b));
}

static void cNotDeclared(int codeLine, const char* name) {
    cError(codeLine, "variable %s has not been declared", name);
}

static void cDeclared(int codeLine, const char* name) {
    cError(codeLine, "%s has already been declared", name);
}

static void cTooMuchArguments(int codeLine) {
    cError(codeLine, "too much function arguments");
}

static void cUnexpectedToken(int codeLine, Token t) {
    cError(codeLine, "unexpected token: %s", tGetName(t));
}

static void cCannotGetSize(int codeLine, DataType dt) {
    cError(codeLine, "cannot get size of data type: %s", cGetName(dt));
}

#define BUFFER_SIZE 256

static void cUnknownFunction(Function* f) {
    int max = 0;
    char buffer[BUFFER_SIZE] = {'\0'};
    for(int i = 0; i < f->arguments; i++) {
        const char* name = dtGetName(&structs, f->argumentTypes[i]);
        max += snprintf(buffer + max, (size_t)(BUFFER_SIZE - max),
                        i > 0 ? ", %s" : "%s", name);
    }
    cError(__LINE__, "unknown function: %s(%s)", f->name, buffer);
}

static void cAddOperation(Operation token) {
    unsigned char c = token;
    bcAddBytes(code, &c, 1);
}

static int32 cReserveInt32(void) {
    return bcReserveBytes(code, sizeof(int32));
}

static void cSetInt32(int p, int32 i) {
    bcSetBytes(code, p, &i, sizeof(int32));
}

static void cAddInt32(int32 i) {
    bcAddBytes(code, &i, sizeof(int32));
}

static void cAddInt32Operation(Operation token, int32 i) {
    cAddOperation(token);
    cAddInt32(i);
}

static void cAddByteOperation(Operation token, int8 i) {
    cAddOperation(token);
    bcAddBytes(code, &i, sizeof(int8));
}

static void cAddLine(int16 l) {
    cAddOperation(OP_LINE);
    bcAddBytes(code, &l, sizeof(int16));
}

static Token cReadTokenAndLine(void) {
    hasReturn--;
    Token t;
    if(tReadTokenAndLine(&t, &line)) {
        return T_END;
    }
    return t;
}

static void cConsumeToken(Token wanted) {
    Token t = cReadTokenAndLine();
    if(wanted != t) {
        cError(__LINE__, "expected '%s' got '%s'", tGetName(wanted),
               tGetName(t));
    }
}

static bool cConsumeTokenIf(Token t) {
    return tPeekToken() == t && cReadTokenAndLine() == t;
}

static void cConstantInt32(void) {
    int32 value;
    if(tReadInt32(&value)) {
        cError(__LINE__, "int token without an int");
    }
    cAddInt32Operation(OP_PUSH_INT, value);
}

static void cConstantFloat(void) {
    float value;
    if(tReadFloat(&value)) {
        cError(__LINE__, "float token without a float");
    }
    cAddOperation(OP_PUSH_FLOAT);
    bcAddBytes(code, &value, sizeof(float));
}

static const char* cReadString(void) {
    const char* literal = tReadString();
    if(literal == NULL) {
        cError(__LINE__, "literal without string");
    }
    return literal;
}

static int cGetSize(DataType dt) {
    int size;
    if(dtGetSize(dt, &structs, &size)) {
        cError(__LINE__, "cannot get size of data type");
    }
    return size;
}

static DataType cExtendType(DataType dt) {
    if(cConsumeTokenIf(T_OPEN_SQUARE_BRACKET)) {
        cConsumeToken(T_CLOSE_SQUARE_BRACKET);
        dt = dtToArray(dt);
    }
    return dt;
}

static DataType cReadType(Token t, bool force) {
    switch(t) {
        case T_INT: return dtInt();
        case T_FLOAT: return dtFloat();
        case T_LITERAL: {
            const char* name = cReadString();
            Struct* st = stsSearch(&structs, name);
            if(st == NULL) {
                if(force) {
                    cError(__LINE__, "struct %s does not exist", name);
                } else {
                    return dtVoid();
                }
            }
            return dtStruct(st);
        }
        default:
            if(force) {
                cUnexpectedToken(__LINE__, t);
            }
            return dtVoid();
    }
}

static DataType cReadExtendedType(Token t, bool force) {
    DataType dt = cReadType(t, force);
    if(!dtIsVoid(dt)) {
        dt = cExtendType(dt);
    }
    return dt;
}

static DataType cExpression(void);

static void cLoadRef(DataType type) {
    if(dtIsArray(type)) {
        cAddOperation(OP_LOAD_ARRAY);
        return;
    }
    switch(dtGetType(type)) {
        DT_OPERATION(LOAD);
        default: cError(__LINE__, "cannot load type %s", cGetName(type));
    }
}

static DataType cUnpack(DataType dt) {
    if(!dtIsStruct(dt) && dtRemovePointer(&dt)) {
        cLoadRef(dt);
    }
    return dt;
}

static DataType cUnpackedExpression(void) {
    return cUnpack(cExpression());
}

static void cCallFunctionArguments(Function* f) {
    if(cConsumeTokenIf(T_CLOSE_BRACKET)) {
        return;
    }
    while(true) {
        DataType dt = cUnpackedExpression();
        if(fAddArgument(f, dt, &structs)) {
            cTooMuchArguments(__LINE__);
        } else if(cConsumeTokenIf(T_CLOSE_BRACKET)) {
            return;
        }
        cConsumeToken(T_COMMA);
    }
}

static DataType cCallFunction(const char* name) {
    int returnAddress = bcGetAddress(code);
    Function f;
    fInit(&f, name, line);
    int oldOnLine = onLine;
    onLine = false;
    cCallFunctionArguments(&f);
    onLine = oldOnLine;
    Function* found = fsSearch(&functions, &f);
    if(found == NULL) {
        cUnknownFunction(&f);
    } else if(found->global) {
        cAddInt32Operation(OP_CALL, found->line);
        return found->returnType;
    }
    char push[1 + sizeof(int32)] = {OP_PUSH_INT};
    bcInsertBytes(code, push, sizeof(push), returnAddress);
    cAddOperation(OP_GOSUB);
    if(found->address == -1) {
        f.returnType = found->returnType;
        f.address = cReserveInt32();
        fsAdd(&functionQueue, &f);
    } else {
        cAddInt32(found->address);
    }
    cAddInt32(found->size);
    return found->returnType;
}

static void cStore(DataType left, DataType right, const char* name) {
    if(dtIsArray(left)) {
        if(!dtCompare(left, right)) {
            cInvalidOperation(__LINE__, left, right, name);
        }
        cAddOperation(OP_STORE_ARRAY);
        return;
    }
    if(!dtCompare(left, right)) {
        cInvalidOperation(__LINE__, left, right, name);
    }
    switch(dtGetType(left)) {
        DT_OPERATION(STORE);
        default: cError(__LINE__, "cannot store type %s", cGetName(left));
    }
}

static DataType cLiteral(void) {
    const char* literal = cReadString();
    if(cConsumeTokenIf(T_OPEN_BRACKET)) {
        return cCallFunction(literal);
    }
    Variable v;
    if(!vsSearch(&vars, &v, literal)) {
        if(dtIsPointer(v.type)) {
            if(!dtIsStruct(v.type)) {
                cError(__LINE__,
                       "non struct type %s should not be a pointer here",
                       cGetName(v.type));
            }
            cAddInt32Operation(OP_PUSH_STRUCT_REFERENCE, v.address);
        } else {
            cAddInt32Operation(OP_DEREFERENCE_VAR, v.address);
        }
        return dtToPointer(v.type);
    } else if(!vsSearch(&globalVars, &v, literal)) {
        cAddInt32Operation(OP_DEREFERENCE_GVAR, v.address);
        return dtToPointer(v.type);
    }
    cNotDeclared(__LINE__, literal);
    return dtVoid();
}

static DataType cText(void) {
    cAddOperation(OP_PUSH_TEXT);
    int32 lengthAddress = cReserveInt32();
    int32 length = 0;
    int32 c;
    while(!tReadInt32(&c) && c != 0) {
        cAddInt32(c);
        length++;
    }
    cSetInt32(lengthAddress, length);
    return dtText();
}

static DataType cBracketPrimary(void) {
    DataType result = cExpression();
    cConsumeToken(T_CLOSE_BRACKET);
    return result;
}

static void cArrayIndex(void) {
    if(!dtIsInt(cUnpackedExpression())) {
        cError(__LINE__, "array index must be an int");
    }
}

static DataType cAllocArray(void) {
    DataType dt = cReadType(cReadTokenAndLine(), true);
    if(dtIsArray(dt)) {
        cError(__LINE__, "array type must not be an array");
    }
    cConsumeToken(T_OPEN_SQUARE_BRACKET);
    cArrayIndex();
    cConsumeToken(T_CLOSE_SQUARE_BRACKET);
    cAddInt32Operation(OP_NEW, cGetSize(dt));
    return dtToArray(dt);
}

static DataType cLength(void) {
    DataType array = cUnpackedExpression();
    if(!dtIsArray(array)) {
        cError(__LINE__, "length expects an array");
    }
    cAddOperation(OP_LENGTH);
    return dtInt();
}

static DataType cPrimary(void) {
    Token t = cReadTokenAndLine();
    switch(t) {
        case T_INT_VALUE: cConstantInt32(); return dtInt();
        case T_FLOAT_VALUE: cConstantFloat(); return dtFloat();
        case T_TEXT: return cText();
        case T_OPEN_BRACKET: return cBracketPrimary();
        case T_LITERAL: return cLiteral();
        case T_NEW: return cAllocArray();
        case T_LENGTH: return cLength();
        default: cUnexpectedToken(__LINE__, t); return dtVoid();
    }
}

static void cRemoveReference(DataType* dt, const char* name) {
    if(!dtRemovePointer(dt)) {
        cError(__LINE__, "%s needs a reference not %s", name, cGetName(*dt));
    }
}

static void cExpectType(DataType actual, DataType wanted, const char* name) {
    if(!dtCompare(actual, wanted)) {
        cError(__LINE__, "%s needs %s not %s", name, cGetName(wanted),
               cGetName(actual));
    }
}

static void cChangeType(DataType* dt, Operation op, Operation pushOp,
                        int8 change) {
    if(onLine) {
        cAddByteOperation(op, change);
        *dt = dtVoid();
    } else {
        cAddByteOperation(pushOp, change);
    }
}

static void cPostChange(DataType* dt, int8 change, const char* name) {
    cRemoveReference(dt, name);
    if(dtIsInt(*dt)) {
        cChangeType(dt, OP_CHANGE_INT, OP_PUSH_POST_CHANGE_INT, change);
    } else {
        cError(__LINE__, "%s needs an int not %s", name, cGetName(*dt));
    }
}

static DataType cStructAccess(DataType dt) {
    Struct* st = dtGetStruct(&structs, dt);
    if(st == NULL) {
        cError(__LINE__, ". expects a struct not %s", cGetName(dt));
    }
    cConsumeToken(T_LITERAL);
    const char* name = cReadString();
    Variable inner;
    switch(vSearchStruct(&inner, &structs, st, name)) {
        case VE_CANNOT_FIND:
            cError(__LINE__, "%s has no member %s", st->name, name);
            break;
        case VE_SIZE_ERROR: cCannotGetSize(__LINE__, dt); break;
        default: break;
    }
    if(inner.address > 0) {
        cAddInt32Operation(OP_PUSH_INT, inner.address);
        cAddInt32Operation(OP_ADD_REFERENCE, 1);
    }
    return dtToPointer(inner.type);
}

static DataType cAccess(void) {
    DataType dt = cPrimary();
    while(true) {
        if(cConsumeTokenIf(T_INCREMENT)) {
            cPostChange(&dt, 1, "++");
        } else if(cConsumeTokenIf(T_DECREMENT)) {
            cPostChange(&dt, -1, "--");
        } else if(cConsumeTokenIf(T_POINT)) {
            cRemoveReference(&dt, ".");
            dt = cStructAccess(dt);
        } else if(cConsumeTokenIf(T_OPEN_SQUARE_BRACKET)) {
            if(!dtIsArray(dt)) {
                cError(__LINE__, "[] needs an array");
            }
            cAddOperation(OP_LOAD_ARRAY);
            dtRemovePointer(&dt);
            cArrayIndex();
            cConsumeToken(T_CLOSE_SQUARE_BRACKET);
            cAddInt32Operation(OP_ADD_REFERENCE, cGetSize(dt));
            dt = dtToPointer(dtRemoveArray(dt));
        } else {
            return dt;
        }
    }
}

static DataType cPreChange(DataType dt, int8 change, const char* name) {
    cRemoveReference(&dt, name);
    if(dtIsInt(dt)) {
        cChangeType(&dt, OP_CHANGE_INT, OP_PUSH_PRE_CHANGE_INT, change);
    } else {
        cError(__LINE__, "%s needs an int not %s", name, cGetName(dt));
    }
    return dt;
}

static DataType cInvertSign(DataType dt) {
    if(dtIsInt(dt)) {
        cAddOperation(OP_INVERT_SIGN_INT);
    } else if(dtIsFloat(dt)) {
        cAddOperation(OP_INVERT_SIGN_FLOAT);
    } else {
        cError(__LINE__, "cannot invert sign of %s", cGetName(dt));
    }
    return dt;
}

static DataType cCast(DataType in, DataType a, Operation aOp, DataType out) {
    if(dtCompare(in, a)) {
        cAddOperation(aOp);
    } else {
        cError(__LINE__, "cannot cast %s to %s", cGetName(in), cGetName(out));
    }
    return out;
}

static DataType cUnaryNot(DataType dt) {
    cExpectType(dt, dtInt(), "!");
    cAddOperation(OP_NOT);
    return dt;
}

static DataType cUnaryBitNot(DataType dt) {
    if(dtIsInt(dt)) {
        cAddOperation(OP_BIT_NOT_INT);
    } else {
        cError(__LINE__, "~ needs an int not %s", cGetName(dt));
    }
    return dt;
}

static DataType cPreUnary(void) {
    int marker = tGetMarker();
    if(cConsumeTokenIf(T_OPEN_BRACKET)) {
        if(cConsumeTokenIf(T_FLOAT) && cConsumeTokenIf(T_CLOSE_BRACKET)) {
            return cCast(cUnpack(cPreUnary()), dtInt(), OP_INT_TO_FLOAT,
                         dtFloat());
        } else if(cConsumeTokenIf(T_INT) && cConsumeTokenIf(T_CLOSE_BRACKET)) {
            return cCast(cUnpack(cPreUnary()), dtFloat(), OP_FLOAT_TO_INT,
                         dtInt());
        }
    }
    tReset(marker);
    if(cConsumeTokenIf(T_INCREMENT)) {
        return cPreChange(cPreUnary(), 1, "++");
    } else if(cConsumeTokenIf(T_DECREMENT)) {
        return cPreChange(cPreUnary(), -1, "--");
    } else if(cConsumeTokenIf(T_SUB)) {
        return cInvertSign(cUnpack(cPreUnary()));
    } else if(cConsumeTokenIf(T_NOT)) {
        return cUnaryNot(cPreUnary());
    } else if(cConsumeTokenIf(T_BIT_NOT)) {
        return cUnaryBitNot(cPreUnary());
    }
    return cAccess();
}

static void cAddTypeOperation(DataType* a, Parser bf, const TypedOp* op) {
    *a = cUnpack(*a);
    DataType b = cUnpack(bf());
    if(!dtCompare(*a, b)) {
        cInvalidOperation(__LINE__, *a, b, op->name);
    } else if(dtIsInt(*a) && op->intOp != OP_NOTHING) {
        cAddOperation(op->intOp);
    } else if(dtIsFloat(*a) && op->floatOp != OP_NOTHING) {
        cAddOperation(op->floatOp);
    } else if(dtIsArray(*a) && op->pointerOp != OP_NOTHING) {
        cAddOperation(op->pointerOp);
    } else {
        cInvalidOperation(__LINE__, *a, b, op->name);
    }
}

static DataType cMul(void) {
    DataType a = cPreUnary();
    while(true) {
        if(cConsumeTokenIf(T_MUL)) {
            cAddTypeOperation(&a, cPreUnary, &TYPED_MUL);
        } else if(cConsumeTokenIf(T_DIV)) {
            cAddTypeOperation(&a, cPreUnary, &TYPED_DIV);
        } else if(cConsumeTokenIf(T_MOD)) {
            cAddTypeOperation(&a, cPreUnary, &TYPED_MOD);
        } else {
            return a;
        }
    }
}

static DataType cAdd(void) {
    DataType a = cMul();
    while(true) {
        if(cConsumeTokenIf(T_ADD)) {
            cAddTypeOperation(&a, cMul, &TYPED_ADD);
        } else if(cConsumeTokenIf(T_SUB)) {
            cAddTypeOperation(&a, cMul, &TYPED_SUB);
        } else {
            return a;
        }
    }
}

static DataType cShift(void) {
    DataType a = cAdd();
    while(true) {
        if(cConsumeTokenIf(T_LEFT_SHIFT)) {
            cAddTypeOperation(&a, cAdd, &TYPED_LEFT_SHIFT);
        } else if(cConsumeTokenIf(T_RIGHT_SHIFT)) {
            cAddTypeOperation(&a, cAdd, &TYPED_RIGHT_SHIFT);
        } else {
            return a;
        }
    }
}

static DataType cComparison(void) {
    DataType a = cShift();
    while(true) {
        if(cConsumeTokenIf(T_LESS)) {
            cAddTypeOperation(&a, cShift, &TYPED_LESS);
            a = dtInt();
        } else if(cConsumeTokenIf(T_LESS_EQUAL)) {
            cAddTypeOperation(&a, cShift, &TYPED_LESS_EQUAL);
            a = dtInt();
        } else if(cConsumeTokenIf(T_GREATER)) {
            cAddTypeOperation(&a, cShift, &TYPED_GREATER);
            a = dtInt();
        } else if(cConsumeTokenIf(T_GREATER_EQUAL)) {
            cAddTypeOperation(&a, cShift, &TYPED_GREATER_EQUAL);
            a = dtInt();
        } else {
            return a;
        }
    }
}

static DataType cEqual(void) {
    DataType a = cComparison();
    while(true) {
        if(cConsumeTokenIf(T_EQUAL)) {
            cAddTypeOperation(&a, cComparison, &TYPED_EQUAL);
            a = dtInt();
        } else if(cConsumeTokenIf(T_NOT_EQUAL)) {
            cAddTypeOperation(&a, cComparison, &TYPED_NOT_EQUAL);
            a = dtInt();
        } else {
            return a;
        }
    }
}

static DataType cRepeat(Token t, Parser f, const TypedOp* op) {
    DataType a = f();
    while(cConsumeTokenIf(t)) {
        cAddTypeOperation(&a, f, op);
    }
    return a;
}

static DataType cBitAnd(void) {
    return cRepeat(T_BIT_AND, cEqual, &TYPED_BIT_AND);
}

static DataType cBitXor(void) {
    return cRepeat(T_BIT_XOR, cBitAnd, &TYPED_BIT_XOR);
}

static DataType cBitOr(void) {
    return cRepeat(T_BIT_OR, cBitXor, &TYPED_BIT_OR);
}

static DataType cLogical(Parser f, Token t, Operation jump, Operation op) {
    DataType a = f();
    while(cConsumeTokenIf(t)) {
        cAddOperation(jump);
        int32 p = cReserveInt32();
        DataType b = f();
        if(!dtIsInt(a) || !dtIsInt(b)) {
            cInvalidOperation(__LINE__, a, b, tGetName(t));
        }
        cAddOperation(op);
        cSetInt32(p, code->length);
    }
    return a;
}

static DataType cAnd(void) {
    return cLogical(cBitOr, T_AND, OP_PEEK_FALSE_GOTO, OP_AND);
}

static DataType cExpression(void) {
    return cLogical(cAnd, T_OR, OP_PEEK_TRUE_GOTO, OP_OR);
}

static void cLine(void);

static void cConsumeBody(void) {
    int16 oldLine = line;
    while(!cConsumeTokenIf(T_CLOSE_CURVED_BRACKET)) {
        if(tPeekToken() == T_END) {
            line = oldLine;
            cError(__LINE__, "non closed curved bracket");
        }
        cLine();
    }
}

static void cConsumeScope(void) {
    Scope scope;
    vsEnterScope(&vars, &scope);
    cConsumeBody();
    vsLeaveScope(&vars, &scope);
}

static void cAddReturn(Operation op) {
    if(returnIndex >= RETURN_BUFFER) {
        cError(__LINE__, "too much returns in function");
    }
    cAddOperation(op);
    returns[returnIndex++] = cReserveInt32();
}

static void cReturn(void) {
    if(dtIsVoid(returnType)) {
        cConsumeToken(T_SEMICOLON);
        cAddReturn(OP_RETURN);
        hasReturn = 2;
        return;
    }
    DataType dt = cUnpackedExpression();
    if(!dtCompare(returnType, dt)) {
        cError(__LINE__, "wrong return type, should be %s",
               cGetName(returnType));
    } else if(dtIsInt(dt)) {
        cAddReturn(OP_RETURN_INT);
    } else if(dtIsFloat(dt)) {
        cAddReturn(OP_RETURN_FLOAT);
    } else if(dtIsArray(dt)) {
        cAddReturn(OP_RETURN_POINTER);
    } else {
        cError(__LINE__, "cannot return %s", cGetName(dt));
    }
    cConsumeToken(T_SEMICOLON);
    hasReturn = 2;
}

static void cIf(void) {
    cConsumeToken(T_OPEN_BRACKET);
    cExpectType(cExpression(), dtInt(), "if");
    cConsumeToken(T_CLOSE_BRACKET);
    cAddOperation(OP_IF_GOTO);
    int32 ifP = cReserveInt32();
    cConsumeToken(T_OPEN_CURVED_BRACKET);
    cConsumeScope();
    cSetInt32(ifP, code->length);
    if(cConsumeTokenIf(T_ELSE)) {
        cAddOperation(OP_GOTO);
        int32 elseP = cReserveInt32();
        cSetInt32(ifP, code->length);
        if(cConsumeTokenIf(T_IF)) {
            cIf();
        } else {
            cConsumeToken(T_OPEN_CURVED_BRACKET);
            cConsumeScope();
        }
        cSetInt32(elseP, code->length);
    }
}

static void cConsumeBreaks(int start, int address) {
    for(int i = start; i < breakIndex; i++) {
        cSetInt32(breaks[i], address);
    }
    breakIndex = start;
}

static void cWhile(void) {
    int start = code->length;
    cConsumeToken(T_OPEN_BRACKET);
    cExpectType(cExpression(), dtInt(), "while");
    cConsumeToken(T_CLOSE_BRACKET);
    cAddOperation(OP_IF_GOTO);
    int32 ifP = cReserveInt32();
    int breakStart = breakIndex;
    forWhileStack++;
    int oldContinue = continueAt;
    continueAt = start;
    cConsumeToken(T_OPEN_CURVED_BRACKET);
    cConsumeScope();
    continueAt = oldContinue;
    forWhileStack--;
    cAddInt32Operation(OP_GOTO, start);
    cSetInt32(ifP, code->length);
    cConsumeBreaks(breakStart, code->length);
}

static void cOperationSet(DataType left, const TypedOp* op) {
    cAddOperation(OP_DUPLICATE_REFERENCE);
    cLoadRef(left);
    cAddTypeOperation(&left, cUnpackedExpression, op);
    cStore(left, left, "=");
}

static void cSetVariable(void) {
    onLine = true;
    DataType dt = cPreUnary();
    onLine = false;
    if(dtIsVoid(dt)) {
        return;
    }
    cRemoveReference(&dt, "setter");
    Token t = cReadTokenAndLine();
    switch(t) {
        case T_SET: cStore(dt, cUnpackedExpression(), "="); break;
        case T_ADD_SET: cOperationSet(dt, &TYPED_ADD); break;
        case T_SUB_SET: cOperationSet(dt, &TYPED_SUB); break;
        case T_MUL_SET: cOperationSet(dt, &TYPED_MUL); break;
        case T_DIV_SET: cOperationSet(dt, &TYPED_DIV); break;
        case T_MOD_SET: cOperationSet(dt, &TYPED_MOD); break;
        case T_BIT_AND_SET: cOperationSet(dt, &TYPED_BIT_AND); break;
        case T_BIT_OR_SET: cOperationSet(dt, &TYPED_BIT_OR); break;
        case T_BIT_XOR_SET: cOperationSet(dt, &TYPED_BIT_XOR); break;
        case T_LEFT_SHIFT_SET: cOperationSet(dt, &TYPED_LEFT_SHIFT); break;
        case T_RIGHT_SHIFT_SET: cOperationSet(dt, &TYPED_RIGHT_SHIFT); break;
        default: cUnexpectedToken(__LINE__, t);
    }
}

static void cDeclareSet(Variables* vs, DataType dt, const char* var,
                        Operation op) {
    if(vsInScope(vs, var)) {
        cDeclared(__LINE__, var);
    }
    Variable* v;
    switch(vsAdd(vs, var, dt, &structs, &v)) {
        case VE_SIZE_ERROR: cCannotGetSize(__LINE__, dt); break;
        default: break;
    }
    if(!dtIsStruct(dt) || dtIsArray(dt)) {
        cConsumeToken(T_SET);
        cAddInt32Operation(op, v->address);
        DataType right = cUnpackedExpression();
        cStore(dt, right, "=");
    }
}

static bool cDeclaration(Token t) {
    DataType dt = cReadExtendedType(t, false);
    if(dtIsVoid(dt)) {
        return false;
    }
    cConsumeToken(T_LITERAL);
    const char* var = cReadString();
    cDeclareSet(&vars, dt, var, OP_DEREFERENCE_VAR);
    return true;
}

static void cLineExpression(void) {
    int marker = tGetMarker();
    Token t = cReadTokenAndLine();
    if(cDeclaration(t)) {
        return;
    }
    tReset(marker);
    cSetVariable();
}

static void cFor(void) {
    Scope scope;
    vsEnterScope(&vars, &scope);

    cConsumeToken(T_OPEN_BRACKET);
    cLineExpression();
    cConsumeToken(T_SEMICOLON);
    int startCheck = code->length;
    cExpectType(cExpression(), dtInt(), "for");
    cConsumeToken(T_SEMICOLON);
    cAddOperation(OP_IF_GOTO);
    int32 end = cReserveInt32();
    cAddOperation(OP_GOTO);
    int32 beginBody = cReserveInt32();
    int startPerLoop = code->length;
    cLineExpression();
    cAddInt32Operation(OP_GOTO, startCheck);
    cConsumeToken(T_CLOSE_BRACKET);
    cSetInt32(beginBody, code->length);
    int breakStart = breakIndex;
    forWhileStack++;
    int oldContinue = continueAt;
    continueAt = startPerLoop;
    cConsumeToken(T_OPEN_CURVED_BRACKET);
    cConsumeBody();
    continueAt = oldContinue;
    forWhileStack--;
    cAddInt32Operation(OP_GOTO, startPerLoop);
    cSetInt32(end, code->length);
    cConsumeBreaks(breakStart, code->length);

    vsLeaveScope(&vars, &scope);
}

static void cBreak(void) {
    if(forWhileStack == 0) {
        cError(__LINE__, "break without for or while");
    } else if(breakIndex >= BREAK_BUFFER) {
        cError(__LINE__, "too much breaks");
    }
    cAddOperation(OP_GOTO);
    breaks[breakIndex++] = cReserveInt32();
    cConsumeToken(T_SEMICOLON);
}

static void cContinue(void) {
    if(forWhileStack == 0) {
        cError(__LINE__, "continue without for or while");
    }
    cAddInt32Operation(OP_GOTO, continueAt);
    cConsumeToken(T_SEMICOLON);
}

static void cLine(void) {
    int marker = tGetMarker();
    Token t = cReadTokenAndLine();
    cAddLine(line);
    switch(t) {
        case T_OPEN_CURVED_BRACKET: cConsumeScope(); break;
        case T_RETURN: cReturn(); break;
        case T_IF: cIf(); break;
        case T_WHILE: cWhile(); break;
        case T_FOR: cFor(); break;
        case T_BREAK: cBreak(); break;
        case T_CONTINUE: cContinue(); break;
        default:
            tReset(marker);
            cLineExpression();
            cConsumeToken(T_SEMICOLON);
    }
}

static void cBuildFunction(Function* f, DataType rType, const char* fName) {
    if(dtIsStruct(rType) && !dtIsArray(rType)) {
        cError(__LINE__, "structs cannot be returned");
    }
    fInit(f, fName, line);
    f->returnType = rType;
    vsReset(&vars);
    cConsumeToken(T_OPEN_BRACKET);
    if(cConsumeTokenIf(T_CLOSE_BRACKET)) {
        return;
    }
    while(true) {
        DataType dt = cReadExtendedType(cReadTokenAndLine(), true);
        cConsumeToken(T_LITERAL);
        const char* name = cReadString();
        if(vsInScope(&vars, name)) {
            cDeclared(__LINE__, name);
        }
        if(dtIsStruct(dt)) {
            dt = dtToPointer(dt);
        }
        Variable* v;
        switch(vsAdd(&vars, name, dt, &structs, &v)) {
            case VE_SIZE_ERROR: cCannotGetSize(__LINE__, dt); break;
            default: break;
        }
        if(fAddArgument(f, dt, &structs)) {
            cTooMuchArguments(__LINE__);
        } else if(cConsumeTokenIf(T_CLOSE_BRACKET)) {
            return;
        }
        cConsumeToken(T_COMMA);
    }
}

static void cAddFunction(Function* found, Function* f) {
    if(found == NULL) {
        fsAdd(&functions, f);
    } else if(found->global) {
        cError(__LINE__, "system functions cannot be overwritten");
    } else if(found->address != -1 || f->address == -1 || found->global) {
        cError(__LINE__, "function registered twice");
    } else if(!dtCompare(found->returnType, f->returnType)) {
        cError(__LINE__, "function redeclared with different return type");
    } else {
        found->address = f->address;
    }
}

static void cInnerFunction(Function* f) {
    cConsumeToken(T_OPEN_CURVED_BRACKET);
    cAddOperation(OP_RESERVE);
    int32 p = cReserveInt32();
    cAddInt32(f->size);
    returnIndex = 0;
    cConsumeScope();
    if(!dtIsVoid(returnType) && hasReturn <= 0) {
        cError(__LINE__, "missing return");
    }
    cAddInt32Operation(OP_RETURN, vars.maxAddress);
    cSetInt32(p, vars.maxAddress);
    for(int i = 0; i < returnIndex; i++) {
        cSetInt32(returns[i], vars.maxAddress);
    }
    returnIndex = 0;
}

static void cFunction(DataType rType, const char* name) {
    Function f;
    cBuildFunction(&f, rType, name);
    Function* found = fsSearch(&functions, &f);
    if(cConsumeTokenIf(T_SEMICOLON)) {
        cAddFunction(found, &f);
        return;
    }
    cAddLine(line);
    cAddOperation(OP_GOTO);
    int32 end = cReserveInt32();
    f.address = code->length;
    cAddFunction(found, &f);
    returnType = rType;
    cInnerFunction(&f);
    cSetInt32(end, code->length);
}

static void cStruct(void) {
    cConsumeToken(T_LITERAL);
    const char* name = cReadString();
    if(stsSearch(&structs, name) != NULL) {
        cError(__LINE__, "struct '%s' registered twice", name);
    }
    Struct* st = stsAdd(&structs, name);
    DataType self = dtStruct(st);
    cConsumeToken(T_OPEN_CURVED_BRACKET);
    while(!cConsumeTokenIf(T_CLOSE_CURVED_BRACKET)) {
        DataType dt = cReadExtendedType(cReadTokenAndLine(), true);
        if(dtCompare(dt, self)) {
            cError(__LINE__, "struct %s contains itself", name);
        }
        cConsumeToken(T_LITERAL);
        stAddVariable(st, cReadString(), dt);
        cConsumeToken(T_SEMICOLON);
    }
    cConsumeToken(T_SEMICOLON);
}

static void cGlobalScope(Token t) {
    if(t == T_OPEN_PATH) {
        path = cReadString();
        // printf("OPEN PATH %s\n", path);
        return;
    } else if(t == T_CLOSE_PATH) {
        path = cReadString();
        // printf("CLOSE OLD PATH - OPEN PATH %s\n", path);
        return;
    } else if(t == T_STRUCT) {
        cStruct();
        return;
    }
    DataType dt = dtVoid();
    if(t != T_VOID) {
        dt = cReadExtendedType(t, true);
    }
    cConsumeToken(T_LITERAL);
    const char* name = cReadString();
    if(tPeekToken() == T_OPEN_BRACKET) {
        cFunction(dt, name);
        return;
    }
    cDeclareSet(&globalVars, dt, name, OP_DEREFERENCE_GVAR);
    cConsumeToken(T_SEMICOLON);
}

static void cCallMain(void) {
    Function f;
    fInit(&f, "main", line);
    Function* found = fsSearch(&functions, &f);
    if(found != NULL && dtIsVoid(found->returnType)) {
        cAddInt32Operation(OP_PUSH_INT, 0);
        cAddInt32Operation(OP_GOSUB, found->address);
        cAddInt32(found->size);
    }
}

static void cForEachLine(void) {
    cAddOperation(OP_GRESERVE);
    int p = cReserveInt32();
    while(true) {
        Token t = cReadTokenAndLine();
        if(t == T_END) {
            break;
        }
        cGlobalScope(t);
    }
    cCallMain();
    cSetInt32(p, globalVars.maxAddress);
    cAddInt32Operation(OP_GRESERVE, -globalVars.maxAddress);
}

static void cLinkQueuedFunctions(void) {
    for(int i = 0; i < functionQueue.entries; i++) {
        Function* f = functionQueue.data + i;
        Function* found = fsSearch(&functions, f);
        if(found == NULL || found->address == -1) {
            line = f->line;
            cUnknownFunction(f);
        }
        cSetInt32(f->address, found->address);
    }
}

static void cAllocAndCompile(void) {
    forWhileStack = 0;
    breakIndex = 0;
    returnType = dtVoid();
    onLine = false;
    vsInit(&vars);
    vsInit(&globalVars);
    fsInit(&functions);
    fsInit(&functionQueue);
    stsInit(&structs);
    if(!setjmp(errorJump)) {
        cForEachLine();
        cLinkQueuedFunctions();
    }
    stsDelete(&structs);
    fsDelete(&functionQueue);
    fsDelete(&functions);
    vsDelete(&globalVars);
    vsDelete(&vars);
}

ByteCode* cCompile(Error* e) {
    error = e;
    eInitSuccess(e);
    code = bcInit();
    cAllocAndCompile();
    if(eHasError(e)) {
        bcDelete(code);
        return NULL;
    }
    return code;
}