/*
  MSP430 Emulator
  Copyright (C) 2020 Rudolf Geosits (rgeosits@live.esu.edu)

  "MSP430 Emulator" is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  "MSP430 Emulator" is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program. If not, see <https://www.gnu.org/licenses/>.
*/

#include "utilities.h"

extern uint8_t* MEMSPACE;

/**
 * @brief This function loads the default TI bootloader code into virtual mem
 * @param virt_addr The location in virtual memory to load the bootloader
 */
void load_bootloader(uint16_t virt_addr)
{
    uint16_t *real_addr = get_addr_ptr(virt_addr);
  
    memmove(real_addr, blc, sizeof blc);
    printf("Loaded booloader code into address 0x%04X\n", virt_addr);
}

/**
 * @brief This function loads firmware from a binary file on disk into the
 * virtual memory of the emulated device at base virt_loc
 * @param file_name The file name of the binary to load into virtual memory
 * @param virt_loc The location in virtual memory to load the firmware
 */
int load_firmware(Emulator *emu, char *file_name, uint16_t virt_addr)
{
    uint32_t size, result;
    char str[277] = {0};

    sprintf(str, "Loading firmware: ( %s )\n", file_name);
  
    printf("%s", str);
    print_console(emu, str);

    FILE *fd = fopen(file_name, "rb+");
  
    if (fd == NULL)
    {
        printf("Could not open %s, exiting.\n", file_name);
        return 1;
    }

    /* obtain file size */
    fseek(fd, 0, SEEK_END);
    size = ftell(fd);
    rewind(fd);

    // check size
    if (size > (0x10000 - 0x0C000))
    {
        printf("SizeTooBig\n");
        print_console(emu, "Flash Size too small to fit your binary. Quitting, please refresh to try again. Ensure you are compiling for the right MSP version.\n");
        usleep(20000);
        return 1;
    }

    uint16_t *real_addr = get_addr_ptr(virt_addr);

    result = fread(real_addr, 1, size, fd);

    sprintf(str, "Placed %d bytes into flash\n\n", result);
    printf("%s", str);
    print_console(emu, str);

    fclose(fd);
    return 0;
}

uint16_t *get_stack_ptr(Emulator *emu)
{
    Cpu *cpu = emu->cpu;
  
    return (uint16_t *) (MEMSPACE + cpu->sp);
}

/**
 * @brief Get the host's pointer to the virtual address of the guest
 * @param virt_addr The virtual address of the guest to translate to a useable
 * one in context of the host
 * @return Pointer to the host's location of the guest's memory address
 */
uint16_t *get_addr_ptr(uint16_t virt_addr)
{
    return (uint16_t *) (MEMSPACE + virt_addr);
}

/**
 * @brief Get a pointer to the register specified by the numeric register value
 * @param cpu A pointer to the CPU structure
 * @param reg The numeric value of the register
 * @return Pointer to the register in question, NULL if register doesn't exist
 */
int16_t *get_reg_ptr(Emulator *emu, uint8_t reg)
{
    Cpu *cpu = emu->cpu;

    static int16_t r2 = 0;
    
    switch (reg)
    {    
        case 0x0: return (int16_t *) &cpu->pc;
        case 0x1: return (int16_t *) &cpu->sp;

        case 0x2:
        {
            r2 = sr_to_value(emu);
            return &r2;
        }
            
        case 0x3: return &cpu->cg2;
        case 0x4: return &cpu->r4;
        case 0x5: return &cpu->r5;
        case 0x6: return &cpu->r6;
        case 0x7: return &cpu->r7;
        case 0x8: return &cpu->r8;
        case 0x9: return &cpu->r9;
        case 0xA: return &cpu->r10;
        case 0xB: return &cpu->r11;
        case 0xC: return &cpu->r12;
        case 0xD: return &cpu->r13;
        case 0xE: return &cpu->r14;
        case 0xF: return &cpu->r15;
            
        default:
        {
            puts("Invalid Register Number");
            return 0;
        }
    }
}

/**
 * @brief Convert register ASCII name to it's respective numeric value
 * @param name The register's ASCII name
 * @return The numeric equivalent for the register on success, -1 if an 
 * invalid name was supplied
 */
int8_t reg_name_to_num(char *name)
{
    if ( !strncasecmp("%r0", name, sizeof "%r0") ||
         !strncasecmp("r0", name, sizeof "r0")   ||
         !strncasecmp("%pc", name, sizeof "%pc") ||
         !strncasecmp("pc", name, sizeof "pc") )
    {
        return 0;
    }
    else if ( !strncasecmp("%r1", name, sizeof "%r1")   ||
	          !strncasecmp("r1", name, sizeof "r1")     ||
	          !strncasecmp("%sp", name, sizeof "%sp")   ||
	          !strncasecmp("sp", name, sizeof "sp") )
    {
        return 1;
    }
    else if ( !strncasecmp("%r2", name, sizeof "%r2") ||
	        !strncasecmp("r2", name, sizeof "r2")     ||
	        !strncasecmp("%sr", name, sizeof "%sr")     ||
	        !strncasecmp("sr", name, sizeof "sr") ) {
    
        return 2;
    }
    else if ( !strncasecmp("%r3", name, sizeof "%r3") ||
	        !strncasecmp("r3", name, sizeof "r3")     ||
	        !strncasecmp("%cg2", name, sizeof "%cg2") ||
	        !strncasecmp("cg2", name, sizeof "cg2") ) {                        
        
        return 3;
    }
    else if ( !strncasecmp("%r4", name, sizeof "%r4") ||
	        !strncasecmp("r4", name, sizeof "r4") ) {
    
        return 4;
    }
    else if ( !strncasecmp("%r5", name, sizeof "%r5") ||
	        !strncasecmp("r5", name, sizeof "r5") ) {
    
        return 5;
    }
    else if ( !strncasecmp("%r6", name, sizeof "%r6") ||
	        !strncasecmp("r6", name, sizeof "r6") ) {
    
        return 6;
    }
    else if ( !strncasecmp("%r7", name, sizeof "%r7") ||
	        !strncasecmp("r7", name, sizeof "r7") ) {
    
        return 7;
    }
    else if ( !strncasecmp("%r8", name, sizeof "%r8") ||
	        !strncasecmp("r8", name, sizeof "r8") ) {
    
        return 8;
    }
    else if ( !strncasecmp("%r9", name, sizeof "%r9") ||
	        !strncasecmp("r9", name, sizeof "r9") ) {
    
        return 9;
    }
    else if ( !strncasecmp("%r10", name, sizeof "%r10") ||
	        !strncasecmp("r10", name, sizeof "r10") ) {
    
        return 10;
    }
    else if ( !strncasecmp("%r11", name, sizeof "%r11") ||
	        !strncasecmp("r11", name, sizeof "r11") ) {
    
        return 11;
    }
    else if ( !strncasecmp("%r12", name, sizeof "%r12") ||
	        !strncasecmp("r12", name, sizeof "r12") ) {
    
        return 12;
    }
    else if ( !strncasecmp("%r13", name, sizeof "%r13") ||
	        !strncasecmp("r13", name, sizeof "r13") ) {
    
        return 13;
    }
    else if ( !strncasecmp("%r14", name, sizeof "%r14") ||
	        !strncasecmp("r14", name, sizeof "r14") ) {
    
        return 14;
    }
    else if ( !strncasecmp("%r15", name, sizeof "%r15") ||
	        !strncasecmp("r15", name, sizeof "r15") ) {
    
        return 15;
    }
    
    return -1;
}

/**
 * @brief Convert register number into its ASCII name
 * @param number The register number (0, 1, 2, ...) associated with a 
 * register's name like (R0, R1, R2, ...)
 * @param name A pointer to an allocated character array to fill up with
 * the register's ASCII name
 */
void reg_num_to_name(uint8_t number, char *name)
{    
    switch (number)
    { 
        case 0x0:
        {
            strncpy(name, "PC\0", 3);
            return;
        }
        case 0x1:
        {
            strncpy(name, "SP\0", 3);
            return;
        }
        case 0x2:
        {
            strncpy(name, "SR\0", 3);
            return;
        }
        case 0x3:
        {
            strncpy(name, "R3\0", 3);
            return;
        }
        case 0x4:
        {
            strncpy(name, "R4\0", 3);
            return;
        }
        case 0x5:
        {
            strncpy(name, "R5\0", 3);
            return;
        }
        case 0x6:
        {
            strncpy(name, "R6\0", 3);
            return;
        }
        case 0x7:
        {
            strncpy(name, "R7\0", 3);
            return;
        }
        case 0x8:
        {
            strncpy(name, "R8\0", 3);
            return;
        }
        case 0x9:
        {
            strncpy(name, "R9\0", 3);
            return;
        }
        case 0xA:
        {
            strncpy(name, "R10\0", 4);
            return;
        }
        case 0xB:
        {
            strncpy(name, "R11\0", 4);
            return;
        }
        case 0xC:
        {
            strncpy(name, "R12\0", 4);
            return;
        }
        case 0xD:
        {
            strncpy(name, "R13\0", 4);
            return;
        }
        case 0xE:
        {
            strncpy(name, "R14\0", 4);
            return;
        }
        case 0xF:
        {
            strncpy(name, "R15\0", 4);
            return;
        }
        default:
        {
            strncpy(name, "???\0", 4);
            return;
        }
    }
}

/**
 * @brief This function displays the help menu to the user if he (or - but in
 * practice all too seldom - she) enters incorrect parameters or prompts the 
 * help menu with "help" or "h"
 */
const char* LocalHelpStr =
"**************************************************\n"\
"*\t\tMSP430-Emulator\n*\n*\tUsage: ./msp430 BINARY_FIRMWARE\n*\n"\
"* run\t\t\t[Run Program Until Breakpoint is Hit]\n"\
"* step [N]\t\t[Step Into Instruction]\n"\
"* dump [HEX_ADDR|Rn]\t[Dump Memory direct or at register value]\n"\
"* set [HEX_ADDR|Rn]\t[Set Memory or Register Location]\n"\
"* dis [N][HEX_ADDR]\t[Disassemble Instructions]\n"\
"* break ADDR\t\t[Set a Breakpoint]\n"\
"* bps\t\t\t[Display Breakpoints]\n"\
"* regs\t\t\t[Display Registers]\n"\
"* CTRL+C\t\t[Pause Execution]\n"\
"* reset\t\t\t[Reset Machine]\n"\
"* quit\t\t\t[Exit program]\n"\
"**************************************************\n";

const char* WebHelpStr =
"--------------------------------------------------\n"\
" \t\t[MSP430-Emulator]\n"\
" run\t\t\t[Run Program Until Breakpoint is Hit]\n"\
" step [N]\t\t[Step Into Instruction]\n"\
" dump [HEX_ADDR|Rn]\t[Dump Memory direct or at register value]\n"\
" set [HEX_ADDR|Rn]\t[Set Memory or Register Location]\n"\
" dis [N][HEX_ADDR]\t[Disassemble Instructions]\n"\
" break ADDR\t\t[Set a Breakpoint]\n"\
" bps\t\t\t[Display Breakpoints]\n"\
" regs\t\t\t[Display Registers]\n"\
" reset\t\t\t[Reset Machine]\n"\
" quit\t\t\t[Exit program]\n"\
"--------------------------------------------------\n";

void display_help(Emulator *emu)
{
    Debugger *deb = emu->debugger;

    if (deb->web_interface)
    {
        print_console(emu, WebHelpStr);
    }
    else
    {
        puts(LocalHelpStr);
    }
}