/* test harness - we build this to a shared object and then run it from Lua */
/* see the ../test directory */

#include <stdlib.h>
#include <stdio.h>
#include <lua.h>
#include <lcq/6502.h>

static l6502_emu *get_emu(lua_State *l) {
    l6502_emu *e = lua_touserdata(l, 1);
    if (!e) { lua_pushliteral(l, "expected emulator as first argument"); lua_error(l); }
    return e;
}

int emu_summary(lua_State *l);
int emu_summary(lua_State *l) {
    l6502_emu *e = get_emu(l);
    lua_newtable(l);
    lua_pushinteger(l, e->pc); lua_setfield(l, -2, "pc");
    lua_newtable(l);
    lua_pushinteger(l, e->regs[L6502_REG_SP]); lua_setfield(l, -2, "sp");
    lua_pushinteger(l, e->regs[L6502_REG_A]); lua_setfield(l, -2, "a");
    lua_pushinteger(l, e->regs[L6502_REG_X]); lua_setfield(l, -2, "x");
    lua_pushinteger(l, e->regs[L6502_REG_Y]); lua_setfield(l, -2, "y");
    lua_setfield(l, -2, "regs");
    lua_newtable(l);
    lua_pushinteger(l, l6502_flag_get(e, L6502_FLAG_CARRY)); lua_setfield(l, -2, "carry");
    lua_pushinteger(l, l6502_flag_get(e, L6502_FLAG_ZERO)); lua_setfield(l, -2, "zero");
    lua_pushinteger(l, l6502_flag_get(e, L6502_FLAG_INTERRUPT_DISABLE)); lua_setfield(l, -2, "interrupt_disable");
    lua_pushinteger(l, l6502_flag_get(e, L6502_FLAG_DECIMAL)); lua_setfield(l, -2, "decimal");
    lua_pushinteger(l, l6502_flag_get(e, L6502_FLAG_BREAK_COMMAND)); lua_setfield(l, -2, "break_command");
    lua_pushinteger(l, l6502_flag_get(e, L6502_FLAG_OVERFLOW)); lua_setfield(l, -2, "overflow");
    lua_pushinteger(l, l6502_flag_get(e, L6502_FLAG_NEGATIVE)); lua_setfield(l, -2, "negative");
    lua_setfield(l, -2, "flags");
    return 1;
}

int emu_get_reg(lua_State *l);
int emu_get_reg(lua_State *l) {
    l6502_emu *e = get_emu(l);
    l6502_reg r = lua_tointeger(l, 2);
    if (r >= 0 && r < L6502_REG__MARKER) lua_pushinteger(l, e->regs[r]);
    else { lua_pushliteral(l, "invalid register"); lua_error(l); }
    return 1;
}
int emu_set_reg(lua_State *l);
int emu_set_reg(lua_State *l) {
    l6502_emu *e = get_emu(l);
    l6502_reg r = lua_tointeger(l, 2);
    u8 v = (u8) lua_tointeger(l, 3);
    if (r >= 0 && r < L6502_REG__MARKER) e->regs[r] = v;
    else { lua_pushliteral(l, "invalid register"); lua_error(l); }
    lua_pushvalue(l, 1);
    return 1;
}

int emu_get_flag(lua_State *l);
int emu_get_flag(lua_State *l) {
    l6502_emu *e = get_emu(l);
    l6502_flag f = lua_tointeger(l, 2);
    lua_pushboolean(l, l6502_flag_get(e, f));
    return 1;
}
int emu_set_flag(lua_State *l);
int emu_set_flag(lua_State *l) {
    l6502_emu *e = get_emu(l);
    l6502_flag f = lua_tointeger(l, 2);
    bool v = lua_toboolean(l, 3);
    l6502_flag_set(e, f, v);
    lua_pushvalue(l, 1);
    return 1;
}

int emu_get_pc(lua_State *l);
int emu_get_pc(lua_State *l) {
    l6502_emu *e = get_emu(l);
    lua_pushinteger(l, e->pc);
    return 1;
}

int emu_set_pc(lua_State *l);
int emu_set_pc(lua_State *l) {
    l6502_emu *e = get_emu(l);
    e->pc = (u16) lua_tointeger(l, 2);
    lua_pushvalue(l, 1);
    return 1;
}

int emu_read(lua_State *l);
int emu_read(lua_State *l) {
    l6502_emu *e = get_emu(l);
    u16 addr = (u16) lua_tointeger(l, 2);
    lua_pushinteger(l, l6502_read(e, addr));
    return 1;
}

int emu_write(lua_State *l);
int emu_write(lua_State *l) {
    l6502_emu *e = get_emu(l);
    u16 addr = (u16) lua_tointeger(l, 2);
    u8 v = (u8) lua_tointeger(l, 3);
    l6502_write(e, addr, v);
    lua_pushvalue(l, 1);
    return 1;
}

int emu_emulate(lua_State *l);
int emu_emulate(lua_State *l) {
    l6502_emu *e = get_emu(l);
    l6502_emulate(e);
    return 1;
}

int new(lua_State *l);
int new(lua_State *l) {
    l6502_emu *e = lua_newuserdata(l, sizeof(l6502_emu));
    l6502_mem_basic_new(&e->mem);
    lua_newtable(l);
    lua_newtable(l);
    lua_pushcfunction(l, emu_summary); lua_setfield(l, -2, "summary");
    lua_pushcfunction(l, emu_get_reg); lua_setfield(l, -2, "reg");
    lua_pushcfunction(l, emu_set_reg); lua_setfield(l, -2, "set-reg");
    lua_pushcfunction(l, emu_get_flag); lua_setfield(l, -2, "flag");
    lua_pushcfunction(l, emu_set_flag); lua_setfield(l, -2, "set-flag");
    lua_pushcfunction(l, emu_get_pc); lua_setfield(l, -2, "pc");
    lua_pushcfunction(l, emu_set_pc); lua_setfield(l, -2, "set-pc");
    lua_pushcfunction(l, emu_read); lua_setfield(l, -2, "read");
    lua_pushcfunction(l, emu_write); lua_setfield(l, -2, "write");
    lua_pushcfunction(l, emu_emulate); lua_setfield(l, -2, "emulate");
    lua_setfield(l, -2, "__index");
    lua_setmetatable(l, -2);
    return 1;
}

#define PUSH_ENUM(enum, field) { lua_pushinteger(l, enum ## _ ## field); lua_setfield(l, -2, #field); }
static void push_enum_flag(lua_State *l) {
    lua_newtable(l);
    PUSH_ENUM(L6502_FLAG, CARRY);
    PUSH_ENUM(L6502_FLAG, ZERO);
    PUSH_ENUM(L6502_FLAG, INTERRUPT_DISABLE);
    PUSH_ENUM(L6502_FLAG, DECIMAL);
    PUSH_ENUM(L6502_FLAG, BREAK_COMMAND);
    PUSH_ENUM(L6502_FLAG, OVERFLOW);
    PUSH_ENUM(L6502_FLAG, NEGATIVE);
}
static void push_enum_reg(lua_State *l) {
    lua_newtable(l);
    PUSH_ENUM(L6502_REG, SP);
    PUSH_ENUM(L6502_REG, A);
    PUSH_ENUM(L6502_REG, X);
    PUSH_ENUM(L6502_REG, Y);
    PUSH_ENUM(L6502_REG, FLAGS);
}

int luaopen_l6502(lua_State *l);
int luaopen_l6502(lua_State *l) {
    lua_newtable(l);
    push_enum_flag(l); lua_setfield(l, -2, "flag");
    push_enum_reg(l); lua_setfield(l, -2, "reg");
    lua_pushcfunction(l, new); lua_setfield(l, -2, "new");
    return 1;
}