#ifndef ZRL_OPCODES_H
#define ZRL_OPCODES_H

#include "common.h"

typedef enum {
  OP_HALT,   /* halt : terminate execution */
  OP_JMP,    /* jump : jump to address src1 unconditionally */
  OP_CALL,   /* call : creates a new frame */
  OP_RETURN, /* retn : returns from a frame to the parent frame */
  OP_LOAD,   /* load : dest = &[next memory location] */
  OP_STORE,  /* stor : next memory location = src1 as float */
  OP_PUSH, /* push : push str ref from register onto the stack and copy str  */
  OP_POP,  /* pop : pop int from stack onto the register */
  OP_REG_MOV,      /* rmov : dest = src1	   */
  OP_REG_SWAP,     /* rswp : dest = src1, src1 = dest	   */
  OP_MEM_SWAP,     /* mswp : &dest = &src1, &src1 = &dest */
  OP_MEM_MOV,      /* mmov  : &dest = &src1 */
  OP_MEM_ALLOC,    /* aloc : dest [next memory location as size] */
  OP_GET,          /* get  : dest = ptr : dest = memory[ptr] */
  OP_PUT,          /* put  : ptr = src1  : memory[ptr] = src */
  OP_OFFSET,       /* offs : dest = ptr + src1 : dest = p + o */
  OP_SYSCALL,      /* sysc :  */
  OP_ADD_INT,      /* addi : dest = src1 + src2  */
  OP_SUB_INT,      /* subi : dest = src1 - src2  */
  OP_MUL_INT,      /* muli : dest = src1 * src2  */
  OP_DIV_INT,      /* divi : dest = src1 / src2  */
  OP_ADD_UINT,     /* addu : dest = src1 + src2  */
  OP_SUB_UINT,     /* subu : dest = src1 - src2  */
  OP_MUL_UINT,     /* mulu : dest = src1 * src2  */
  OP_DIV_UINT,     /* divu : dest = src1 / src2  */
  OP_ADD_REAL,     /* addr : dest = src1 + src2  */
  OP_SUB_REAL,     /* subr : dest = src1 - src2  */
  OP_MUL_REAL,     /* mulr : dest = src1 * src2  */
  OP_DIV_REAL,     /* divr : dest = src1 / src2  */
  OP_INT_TO_REAL,  /* itor : dest = src1 as real  */
  OP_UINT_TO_REAL, /* utor : dest = src1 as real  */
  OP_REAL_TO_INT,  /* rtoi : dest = src1 as int  */
  OP_REAL_TO_UINT, /* rtou : dest = src1 as uint  */
  OP_JEQ_INT,  /* jeqi : jump to address dest if src1 as int == src2 as int */
  OP_JGT_INT,  /* jgti : jump to address dest if src1 as int > src2 as int*/
  OP_JLT_INT,  /* jlti : jump to address dest if src1 as int < src2 as int */
  OP_JLE_INT,  /* jlei : jump to address dest if src1 as int <= src2 as int */
  OP_JGE_INT,  /* jgei : jump to address dest if src1 as int >= src2 as int*/
  OP_JEQ_UINT, /* jequ : jump to address dest if src1 as int == src2 as uint */
  OP_JGT_UINT, /* jgtu : jump to address dest if src1 as int > src2 as uint*/
  OP_JLT_UINT, /* jltu : jump to address dest if src1 as int < src2 as uint */
  OP_JLE_UINT, /* jleu : jump to address dest if src1 as int <= src2 as uint */
  OP_JGE_UINT, /* jgeu : jump to address dest if src1 as int >= src2 as uint*/
  OP_JEQ_REAL, /* jeqr : jump to address dest if src1 as real == src2 as real */
  OP_JGE_REAL, /* jgtr : jump to address dest if src1 as real >= src2 as real */
  OP_JGT_REAL, /* jltr : jump to address dest if src1 as real > src2 as real */
  OP_JLT_REAL, /* jler : jump to address dest if src1 as real < src2 as real */
  OP_JLE_REAL, /* jger : jump to address dest if src1 as real <= src2 as real */
  OP_INT_TO_STRING,  /* itos : dest = src1 as str */
  OP_UINT_TO_STRING, /* utos : dest = src1 as str */
  OP_REAL_TO_STRING, /* rtos : dest = src1 as str */
  OP_CMP_STRING,     /* cmps : dest = (str == src2) as bool */
  OP_STRING_TO_INT,  /* stoi : dest = src1 as int */
  OP_STRING_TO_UINT, /* stou : dest = src1 as uint */
  OP_STRING_TO_REAL, /* stor : dest = src1 as real */
  /* to remove, just for testing for now */
  OP_DBG_PRINT_STRING,
  OP_DBG_READ_STRING,
} Opcode;

/* defines a uint32 opcode */
#define OP(opcode, dest, src1, src2)                                           \
  ((opcode << 24) | (dest << 16) | (src1 << 8) | src2)

typedef union value_u {
  int32_t i;  /* Integers */
  float f;    /* Float */
  uint32_t u; /* Unsigned integers, also used for pointer address */
  char c[4];  /* 4 Byte char array for string packing */
} Value;

typedef struct slice_s {
  uint32_t start;
  uint32_t end;
} Slice;

#define MAX_REGS 32
typedef struct frame_s {
  Value registers[MAX_REGS]; /* R0-R31 */
  uint32_t rp;               /* register pointer (last unused) */
  Slice allocated;           /* start and end of global allocated block */
} Frame;

typedef struct screen_t {
  uint8_t width;
  uint8_t height;
  Slice allocated;
  Value *buffer;
} Screen;

typedef struct mouse_t {
  uint32_t x;
  uint32_t y;
  uint8_t btn1;
  uint8_t btn2;
  uint8_t btn3;
} Mouse;

typedef struct keyboard_t {
  uint32_t length;
  const uint8_t *keys;
} Keyboard;

typedef enum {
  SCREEN,
  MOUSE,
  KEYBOARD,
  CONTROLLER,
  AUDIO,
  TUNNEL,
} Devicecode;

typedef union device_u {
  uint8_t type;
  Screen s;
  Mouse m;
  Keyboard k;
  /* Audio a; */
  /* Tunnel t; */
} Device;

#define MEMORY_SIZE 65536
#define CODE_SIZE 8192
#define FRAMES_SIZE 128
#define STACK_SIZE 256
#define DEVICES_SIZE 8
typedef struct vm_s {
  uint32_t pc; /* program counter */
  uint32_t cp; /* code pointer (last allocated opcode) */
  uint32_t fp; /* frame pointer (current frame) */
  uint32_t sp; /* stack pointer (top of stack) */
  uint32_t rp; /* return stack pointer (top of stack) */
  uint32_t mp; /* memory pointer (last allocated value) */
  uint32_t dp; /* device pointer (last allocated device) */
  uint8_t devices_size;
  Device devices[DEVICES_SIZE];
  uint32_t frames_size;
  Frame frames[FRAMES_SIZE]; /* function call frames */
  uint32_t stack_size;
  Value stack[STACK_SIZE]; /* main stack */
  uint32_t return_stack_size;
  Value return_stack[STACK_SIZE]; /* return stack (for recursion) */
  uint32_t code_size;
  Value code[CODE_SIZE]; /* code block */
  uint32_t memory_size;
  Value memory[MEMORY_SIZE]; /* memory block */
} VM;

#endif