#ifndef GROUND_H
#define GROUND_H

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <uthash.h>

#ifdef _WIN32
// TODO: check if this works
#include <minwindef.h>
#define PATH_MAX MAX_PATH
#else 
#include <limits.h>
#endif

// 
// TYPES
//

// --- Program structure types ---

typedef struct GroundType        GroundType;
typedef struct GroundValue       GroundValue;
typedef struct GroundArg         GroundArg;
typedef struct GroundInstruction GroundInstruction;
typedef struct GroundProgram     GroundProgram;
typedef struct GroundState       GroundState;

typedef struct GroundBytecodeValue       GroundBytecodeValue;
typedef struct GroundBytecodeList        GroundBytecodeList;
typedef struct GroundBytecodeFunction    GroundBytecodeFunction;
typedef struct GroundBytecodeStruct      GroundBytecodeStruct;
typedef struct GroundBytecodeObject      GroundBytecodeObject;
typedef struct GroundBytecodeError       GroundBytecodeError;
typedef struct GroundBytecodeProgram     GroundBytecodeProgram;
typedef struct GroundBytecodeInstruction GroundBytecodeInstruction;
typedef struct GroundBytecodeHeap        GroundBytecodeHeap;
typedef struct GroundBytecode            GroundBytecode;

// --- Literal types ---

typedef int64_t GroundInt;
typedef double  GroundDouble;
typedef char    GroundChar;
typedef bool    GroundBool;

// --- Complex types ---

typedef struct GroundList     GroundList;
typedef struct GroundString   GroundString;
typedef struct GroundFunction GroundFunction;
typedef struct GroundStruct   GroundStruct;
typedef struct GroundObject   GroundObject;
typedef struct GroundError    GroundError;

// --- Helper types --- 

typedef struct GroundIdentifier GroundIdentifier;

typedef struct GroundFunctionArg GroundFunctionArg;

typedef struct GroundObjectField GroundObjectField;

typedef struct GroundVariable GroundVariable;
typedef struct GroundLabel    GroundLabel;
typedef struct GroundCatch    GroundCatch;

typedef uint64_t GroundSize;

// --- Complex types definitions ---

struct GroundString {
    char* cstr;
    GroundSize len;
};

struct GroundList {
    GroundSize capacity;
    GroundSize count;
    GroundValue* at;
};

struct GroundFunction {
    struct {
        GroundSize capacity;
        GroundSize count;
        GroundFunctionArg* at;
    } args;

    bool isNativeFunction;

    union {
        void* native;
        GroundProgram* ground;
    } program;

    GroundState* closure;

    GroundSize _requiredSize;
};

struct GroundStruct {
    GroundObjectField* fields;
};

struct GroundObjectField {
    char           name[2048];
    GroundValue*   value;
    UT_hash_handle hh;
};

struct GroundObject {
    GroundObjectField* fields;
    GroundStruct* type;
};

struct GroundError {
    GroundValue* value;

};

// --- Program structure types definitions ---

enum GroundTypeType {
    GroundType_Int, GroundType_Double, GroundType_Char, GroundType_Bool,
    GroundType_String, GroundType_List,
    GroundType_Function, GroundType_Struct, GroundType_Object,
    GroundType_CoreType,
};

struct GroundType {
    enum GroundTypeType type;
    GroundStruct        complexType;
};

struct GroundFunctionArg {
    union {
        GroundIdentifier* id;
        GroundType type;
    } as;
};

struct GroundValue {
    union {
        GroundInt      Int;
        GroundDouble   Double;
        GroundChar     Char;
        GroundBool     Bool;
        GroundString   String;
        GroundList     List;
        GroundFunction Function;
        GroundStruct   Struct;
        GroundObject   Object;

        enum GroundTypeType CoreType;
    } as;

    GroundType type;
};

enum GroundArgType {
    GroundArg_Value, GroundArg_ValueRef, GroundArg_DirectRef,
    GroundArg_LineRef, GroundArg_Label, 
    GroundArg_FunctionRef, GroundArg_TypeRef
};

struct GroundArg {
    enum GroundArgType type;
    union {
        GroundIdentifier* ref;
        GroundValue value;
    } as;
    
    GroundSize _offset;
};

enum GroundInstructionType {
    // Control flow
    GroundInstruction_IF, GroundInstruction_JUMP, GroundInstruction_END, 
    
    // I/O
    GroundInstruction_INPUT, GroundInstruction_PRINT, GroundInstruction_PRINTLN, 

    // Variable manipulation 
    GroundInstruction_SET, GroundInstruction_GETTYPE, GroundInstruction_EXISTS, 

    // List manipulation
    GroundInstruction_SETLIST, GroundInstruction_SETLISTAT, GroundInstruction_GETLISTAT, 
    GroundInstruction_GETLISTSIZE, GroundInstruction_LISTAPPEND,

    // String manipulation
    GroundInstruction_GETSTRSIZE, GroundInstruction_GETSTRCHARAT, 

    // Math
    GroundInstruction_ADD, GroundInstruction_SUBTRACT, GroundInstruction_MULTIPLY, GroundInstruction_DIVIDE, 

    // Comparison
    GroundInstruction_EQUAL, GroundInstruction_INEQUAL, GroundInstruction_NOT, 
    GroundInstruction_GREATER, GroundInstruction_LESSER, 

    // Bitwise operations
    GroundInstruction_AND, GroundInstruction_OR, GroundInstruction_XOR, 
    GroundInstruction_NEG, GroundInstruction_SHIFT, 

    // Conversions
    GroundInstruction_STOI, GroundInstruction_STOD, GroundInstruction_ITOC, GroundInstruction_CTOI, GroundInstruction_TOSTRING, 

    // Functions
    GroundInstruction_FUN, GroundInstruction_RETURN, GroundInstruction_ENDFUN, 

    // Calling functions
    GroundInstruction_CALL, GroundInstruction_CALLMETHOD, 

    // Structs
    GroundInstruction_STRUCT, GroundInstruction_ENDSTRUCT, GroundInstruction_INIT,
    GroundInstruction_GETFIELD, GroundInstruction_SETFIELD, 
    
    // Libraries
    GroundInstruction_USE, GroundInstruction_EXTERN, 

    // Create labels
    GroundInstruction_CREATELABEL, 

    // Utility
    GroundInstruction_PAUSE, GroundInstruction_DROP, GroundInstruction_LICENSE,

    // Error
    GroundInstruction_ERROR, GroundInstruction_THROW, GroundInstruction_CATCH
};

struct GroundInstruction {
    enum GroundInstructionType type;
    struct {
        GroundSize len;
        GroundSize capacity;
        GroundArg* at;
    } args;
};

struct GroundProgram {
    GroundSize len;
    GroundSize capacity;
    GroundInstruction* at;
};

struct GroundVariable {
    char name[2048];
    GroundValue value;
    UT_hash_handle hh;

    GroundSize _offset;
};

struct GroundLabel {
    char name[2048];
    GroundSize lineNum;
    UT_hash_handle hh;
};

struct GroundCatch {
    char name[2048];
    GroundType type;
    UT_hash_handle hh;
};

struct GroundState {
    GroundVariable* variables;
    GroundLabel* labels;
    GroundCatch* catches;

    GroundSize _size;
};

struct GroundIdentifier {
    char* string;
    GroundSize referenceCount;
};

struct GroundBytecodeList {
    GroundSize capacity;
    GroundSize count;
    GroundBytecodeValue* at;
};
struct GroundBytecodeFunction {
    struct {
        GroundSize capacity;
        GroundSize count;
        GroundFunctionArg* at;
    } args;

    bool isNativeFunction;

    union {
        void* native;
        GroundBytecodeProgram* ground;
    } program;

    GroundBytecodeHeap* closure;

    GroundSize _requiredSize;
};
struct GroundBytecodeStruct {};
struct GroundBytecodeObject {};

struct GroundBytecodeValue {
    union {
        GroundInt      Int;
        GroundDouble   Double;
        GroundChar     Char;
        GroundBool     Bool;
        GroundString   String;

        GroundBytecodeList     List;
        GroundBytecodeFunction Function;
        GroundBytecodeStruct   Struct;
        GroundBytecodeObject   Object;

        // For core types 
        enum GroundTypeType CoreType;
    } as;

    GroundType type;
};

struct GroundBytecodeProgram {
    GroundBytecodeInstruction* at;
    GroundSize capacity;
    GroundSize len;
};

struct GroundBytecodeInstruction {
    enum GroundInstructionType type;
    struct {
        GroundSize* at;
        GroundSize capacity;
        GroundSize len;
    } args;
};

struct GroundBytecodeHeap {
    GroundBytecodeValue* heap;
    GroundSize capacity;
    GroundSize len;
};

struct GroundBytecode {
    GroundBytecodeProgram program;
    GroundBytecodeHeap    heap;
};


// --- Internal Ground components, avoid use outside of Ground ---

enum GroundExecutionResultType {
    _GER_CONTINUE, _GER_JUMP, _GER_RETURN, _GER_END
};

struct GroundExecutionResult {
    enum GroundExecutionResultType type;
    union {
        GroundBytecodeValue value;
        GroundSize line;
        GroundInt end;
    } as;
};

struct GroundOpenSharedObjects {
    char path[PATH_MAX];
    void* handle;
    UT_hash_handle hh;
};

// 
// INTERFACE
// 

struct _Ground {

    struct {
        bool error;
    } Flags;

    struct {

        // Creates a new value of the specified type.
        // Returns a GroundValue
        struct {
            GroundValue (*Int)    (GroundInt in);
            GroundValue (*Double) (GroundDouble in);
            GroundValue (*Char)   (GroundChar in);
            GroundValue (*Bool)   (GroundBool in);

            GroundValue (*List)     (GroundList in);
            GroundValue (*String)   (GroundString in);
            GroundValue (*Function) (GroundFunction in);
            GroundValue (*Struct)   (GroundStruct in);
            GroundValue (*Object)   (GroundObject in);
        } Value;
        
        struct {
            GroundArg (*Value) (GroundValue value);

            GroundArg (*ValueRef)    (GroundIdentifier* ref);
            GroundArg (*DirectRef)   (GroundIdentifier* ref);
            GroundArg (*LineRef)     (GroundIdentifier* ref);
            GroundArg (*LabelRef)    (GroundIdentifier* ref);
            GroundArg (*FunctionRef) (GroundIdentifier* ref);
            GroundArg (*TypeRef)     (GroundIdentifier* ref);
        } Arg;

        GroundList     (*List)     ();
        GroundString   (*String)   (const char* in);
        GroundFunction (*Function) (GroundState* state);
        GroundStruct   (*Struct)   ();
        GroundObject   (*Object)   (GroundStruct* in);
        GroundError    (*Error)    (GroundValue* in);
         
        GroundFunction (*NativeFunction) (void* function, GroundSize argc, ...);

        GroundInstruction (*Instruction) (enum GroundInstructionType type);
        GroundProgram     (*Program)     ();
        GroundType        (*Type)        (enum GroundTypeType type, ...);

        GroundIdentifier* (*Identifier) (const char* id);

        GroundBytecode      (*Bytecode)      (GroundProgram* program, GroundState* state);
        GroundBytecodeValue (*BytecodeValue) (GroundValue value);

    } New;

    // Frees the memory held by the specified struct
    struct {
        void (*Value)    (GroundValue* in);
        void (*List)     (GroundList* in);
        void (*String)   (GroundString* in);
        void (*Function) (GroundFunction* in);
        void (*Struct)   (GroundStruct* in);
        void (*Object)   (GroundObject* in);

        void (*Arg)         (GroundArg* in);
        void (*Instruction) (GroundInstruction* in);
        void (*Program)     (GroundProgram* in);
        void (*State)       (GroundState* state);

        void (*Identifier) (GroundIdentifier* identifier);

        void (*BytecodeValue) (GroundBytecodeValue* value);
    } Free;

    // Creates a copy of the memory held by the specified struct
    struct {
        GroundValue    (*Value)    (GroundValue* in);
        GroundList     (*List)     (GroundList* in);
        GroundString   (*String)   (GroundString* in);
        GroundFunction (*Function) (GroundFunction* in);
        GroundStruct   (*Struct)   (GroundStruct* in);
        GroundObject   (*Object)   (GroundObject* in);

        GroundArg         (*Arg)         (GroundArg* in);
        GroundInstruction (*Instruction) (GroundInstruction* in);
        GroundProgram     (*Program)     (GroundProgram* in);
        GroundState       (*State)       (GroundState* in);

        GroundIdentifier* (*Identifier) (GroundIdentifier* in);

        GroundBytecodeValue (*BytecodeValue) (GroundBytecodeValue* in);
    } Copy;

    struct {
        void (*append) (GroundList* list, GroundValue value);
    } List;

    struct {
        void (*append)  (GroundInstruction* instruction, GroundArg arg);
        int64_t (*execute) (GroundInstruction* instruction, GroundValue* heap);
    } Instruction;

    struct {
        void          (*append)     (GroundProgram* program, GroundInstruction instruction);
        void          (*execute)    (GroundProgram* program, GroundState* state);
        GroundProgram (*preprocess) (GroundProgram* program, GroundState* state);
    } Program;

    struct {
        void (*appendInstruction) (GroundFunction* function, GroundInstruction instruction);
        void (*appendArg) (GroundFunction* function, const char* argName);
    } Function;

    struct {
        void (*addField) (GroundStruct* gs, const char* id, GroundValue value);
    } Struct;

    struct {
        GroundValue* (*findVariable) (GroundState* state, const char* id);
        GroundSize* (*findLabel) (GroundState* state, const char* id);
        GroundCatch* (*findCatch) (GroundState* state, const char* id);
    } State;

    struct {
        void (*run)(GroundProgram* program, GroundState* state);
        void (*giveUpAndCry)();
    } Internal;

    struct {
        void (*Error)   (const char* message);
        void (*Warning) (const char* message);

        void (*printErrors)();

        char* errors[4096];
        GroundSize errorCount;
        char* warnings[4096];
        GroundSize warningCount;
    } Log;

    struct {
        void         (*save) (GroundBytecode* bytecode, const char* path);
        GroundBytecode (*load) (const char* path);
        struct {
            GroundBytecodeValue (*execute)  (GroundBytecodeProgram* program, GroundBytecodeHeap* heap);
            void                (*optimise) (GroundBytecodeProgram* program);
        } Program;
        struct {
            struct GroundExecutionResult (*execute) (GroundBytecodeInstruction* instruction, GroundBytecodeHeap* heap);
        } Instruction;
        struct {
            void         (*set) (GroundBytecodeHeap* heap, GroundSize idx, GroundValue value);
            GroundValue* (*get) (GroundBytecodeHeap* heap, GroundSize idx);
        } Heap;
    } Bytecode;

    struct {
        char* (*Arg)(GroundArg* arg);
        char* (*Heap)(GroundBytecodeHeap* heap);
        char* (*Instruction)(GroundInstruction* instruction);
        char* (*Program)(GroundProgram* program);
        char* (*String)(GroundString* string);
        char* (*Value)(GroundValue* value);

        char* (*BytecodeValue)(GroundBytecodeValue* value);
    } Stringify;

    struct {
        struct GroundOpenSharedObjects* objects;
        void* (*openSharedObject)(char* id);
        void* (*getFunction)(void* handle, char* id);
    } FFI;
};

extern struct _Ground Ground;

#endif