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

#include "DataType.h"

#define ARRAY_NAME 256

static int typeNameIndex = 0;
static int typeNameSwap = 0;
static char typeName[2][ARRAY_NAME];

static bool useGlobals = false;
static Structs globalStructs;

const char* vtGetName(ValueType vt) {
    switch(vt) {
        case VT_INVALID: return "invalid";
        case VT_NOT_SET: return "?";
        case VT_INT: return "int";
        case VT_FLOAT: return "float";
        case VT_POINTER: return "pointer";
        case VT_ARRAY: return "array";
        case VT_LAST: return "invalid";
    }
    return "invalid";
}

#define VALUE_TYPE_MASK ((1u << VALUE_TYPE_BIT_SIZE) - 1u)
#define VALUE_MAX_OFFSET ((1 << (32 - VALUE_TYPE_BIT_SIZE)) - 1)

ValueType vGetType(Value v) {
    uint32 type = v.typeAndOffset & VALUE_TYPE_MASK;
    if(type >= VT_LAST) {
        return VT_INVALID;
    }
    return (ValueType)type;
}

bool vSetType(Value* v, ValueType vt) {
    if(v == NULL || vt < 0 || vt >= VT_LAST) {
        return true;
    }
    v->typeAndOffset = (v->typeAndOffset & ~VALUE_TYPE_MASK) | vt;
    return false;
}

int32 vGetOffset(Value v) {
    return (int32)(v.typeAndOffset >> VALUE_TYPE_BIT_SIZE);
}

bool vSetOffset(Value* v, int32 offset) {
    if(v == NULL || offset < 0 || offset > VALUE_MAX_OFFSET) {
        return true;
    }
    v->typeAndOffset = (v->typeAndOffset & VALUE_TYPE_MASK) |
                       ((uint32)offset << VALUE_TYPE_BIT_SIZE);
    return false;
}

static void dtAppend(const char* s) {
    int index = 0;
    while(typeNameIndex < (ARRAY_NAME - 1) && s[index] != '\0') {
        typeName[typeNameSwap][typeNameIndex] = s[index];
        index++;
        typeNameIndex++;
    }
    typeName[typeNameSwap][typeNameIndex] = '\0';
}

const char* dtGetName(const Structs* sts, DataType dt) {
    typeNameSwap = !typeNameSwap;
    typeNameIndex = 0;
    switch(dtGetType(dt)) {
        case RDT_INT: dtAppend("int"); break;
        case RDT_FLOAT: dtAppend("float"); break;
        case RDT_STRUCT: {
            Struct* s = dtGetStruct(sts, dt);
            if(s != NULL) {
                dtAppend(s->name);
            } else {
                dtAppend("?-struct");
            }
            break;
        }
        case RDT_VOID: dtAppend("void"); break;
        case RDT_INVALID: dtAppend("invalid"); break;
        default: dtAppend("?");
    }
    if(dtIsArray(dt)) {
        dtAppend("[]");
    }
    if(dtIsPointer(dt)) {
        dtAppend("*");
    }
    return typeName[typeNameSwap];
}

bool dtGetSize(DataType dt, const Structs* sts, int* size) {
    if(dtIsPointer(dt)) {
        *size = 1;
        return false;
    }
    switch(dtGetType(dt)) {
        case RDT_INT: *size = 1; return false;
        case RDT_FLOAT: *size = 1; return false;
        case RDT_STRUCT: {
            *size = 0;
            Struct* st = dtGetStruct(sts, dt);
            if(st == NULL) {
                return true;
            }
            for(int i = 0; i < st->amount; i++) {
                int add = 0;
                if(dtGetSize(st->vars[i].type, sts, &add)) {
                    return true;
                }
                *size += add;
            }
            return false;
        }
        case RDT_LAST:
        case RDT_VOID:
        case RDT_INVALID: return true;
    }
    return true;
}

static DataType dtBuild(RawDataType rdt, bool isPointer, bool isArray,
                        int32 structId) {
    if(rdt < 0 || rdt >= RDT_LAST || structId < 0 ||
       structId > DT_MAX_STRUCT_ID) {
        return (DataType){RDT_INVALID};
    }
    return (DataType){((uint32)rdt << DT_TYPE_OFFSET) |
                      ((uint32)isPointer << DT_IS_POINTER_OFFSET) |
                      ((uint32)isArray << DT_IS_ARRAY_OFFSET) |
                      ((uint32)structId << DT_STRUCT_ID_OFFSET)};
}

DataType dtInt(void) {
    return dtBuild(RDT_INT, false, false, 0);
}

DataType dtFloat(void) {
    return dtBuild(RDT_FLOAT, false, false, 0);
}

DataType dtVoid(void) {
    return dtBuild(RDT_VOID, false, false, 0);
}

DataType dtStruct(const Struct* st) {
    return dtBuild(RDT_STRUCT, false, false, st->id);
}

DataType dtText(void) {
    return dtBuild(RDT_INT, false, true, 0);
}

DataType dtToArray(DataType dt) {
    dt.data |= 1 << DT_IS_ARRAY_OFFSET;
    return dt;
}

DataType dtRemoveArray(DataType dt) {
    dt.data &= ~(((1u << DT_IS_ARRAY_BIT_SIZE) - 1u) << DT_IS_ARRAY_OFFSET);
    return dt;
}

DataType dtToPointer(DataType dt) {
    dt.data |= 1 << DT_IS_POINTER_OFFSET;
    return dt;
}

bool dtRemovePointer(DataType* dt) {
    if(dtIsPointer(*dt)) {
        dt->data &=
            ~(((1u << DT_IS_POINTER_BIT_SIZE) - 1u) << DT_IS_POINTER_OFFSET);
        return true;
    }
    return false;
}

RawDataType dtGetType(DataType dt) {
    uint32 type = dt.data & (((1u << DT_TYPE_BIT_SIZE) - 1u) << DT_TYPE_OFFSET);
    if(type >= RDT_LAST) {
        return RDT_INVALID;
    }
    return (RawDataType)type;
}

bool dtCompare(DataType a, DataType b) {
    return a.data == b.data;
}

bool dtIsInt(DataType dt) {
    return dtCompare(dt, dtInt());
}

bool dtIsFloat(DataType dt) {
    return dtCompare(dt, dtFloat());
}

bool dtIsVoid(DataType dt) {
    return dtCompare(dt, dtVoid());
}

bool dtIsArray(DataType dt) {
    return dt.data &
           (((1u << DT_IS_ARRAY_BIT_SIZE) - 1u) << DT_IS_ARRAY_OFFSET);
}

bool dtIsStruct(DataType dt) {
    return dtGetType(dt) == RDT_STRUCT;
}

bool dtIsPointer(DataType dt) {
    return dt.data &
           (((1u << DT_IS_POINTER_BIT_SIZE) - 1u) << DT_IS_POINTER_OFFSET);
}

Struct* dtGetStruct(const Structs* sts, DataType dt) {
    if(!dtIsStruct(dt)) {
        return NULL;
    }
    int32 structId = (int32)((dt.data >> DT_STRUCT_ID_OFFSET) &
                             ((1u << DT_STRUCT_ID_BIT_SIZE) - 1u));
    if(structId & 1) {
        if(!useGlobals) {
            return NULL;
        }
        structId >>= 1;
        if(structId < 0 || structId >= globalStructs.entries) {
            return NULL;
        }
        return globalStructs.data + structId;
    }
    structId >>= 1;
    if(structId < 0 || structId >= sts->entries) {
        return NULL;
    }
    return sts->data + structId;
}

void stAddVariable(Struct* st, const char* name, DataType type) {
    int index = st->amount;
    st->amount++;
    st->vars = (StructVariable*)realloc(st->vars, sizeof(StructVariable) *
                                                      (size_t)st->amount);
    st->vars[index].name = name;
    st->vars[index].type = type;
}

void stsInit(Structs* sts) {
    sts->capacity = 4;
    sts->entries = 0;
    sts->data = (Struct*)malloc(sizeof(Struct) * (size_t)sts->capacity);
}

void stsDelete(Structs* sts) {
    for(int i = 0; i < sts->entries; i++) {
        free(sts->data[i].vars);
    }
    free(sts->data);
}

static Struct* stsInternSearch(Structs* sts, const char* name) {
    for(int i = 0; i < sts->entries; i++) {
        if(strcmp(sts->data[i].name, name) == 0) {
            return sts->data + i;
        }
    }
    return NULL;
}

Struct* stsSearch(Structs* sts, const char* name) {
    if(useGlobals) {
        Struct* st = stsInternSearch(&globalStructs, name);
        if(st != NULL) {
            return st;
        }
    }
    return stsInternSearch(sts, name);
}

Struct* stsAdd(Structs* sts, const char* name) {
    if(sts->entries >= sts->capacity) {
        sts->capacity *= 2;
        sts->data =
            (Struct*)realloc(sts->data, sizeof(Struct) * (size_t)sts->capacity);
    }
    uint16 index = (uint16)sts->entries++;
    sts->data[index].id = (uint16)(index << 1);
    sts->data[index].amount = 0;
    sts->data[index].name = name;
    sts->data[index].vars = NULL;
    return sts->data + index;
}

void gstsInit(void) {
    stsInit(&globalStructs);
    useGlobals = true;
}

void gstsDelete(void) {
    stsDelete(&globalStructs);
    useGlobals = false;
}

Structs* gstsGet(void) {
    return &globalStructs;
}

Struct* gstsAdd(const char* name) {
    Struct* st = stsAdd(&globalStructs, name);
    st->id |= 1;
    return st;
}