#include "flipper.h"
#include "resistors_app.h"
#include "resistor_logic.h"
#include <math.h>

const int CHARS_NUMERIC = 3;
const int CHARS_MULTIPLIER = 7;
const int CHARS_TOLERANCE = 7;
const int CHARS_TEMP_COEFF = 3;
const int CHARS_CALCULATION = 12;

const char BLANK_CALCULATION[] = "           "; // "nnn x 10^nn"
const char BLANK_TOLERANCE[] = "       ";
const char BLANK_TEMP_COEFF[] = "   ";

const int INDEX_NUMERIC = 0;
const int INDEX_MULTIPLIER = 4;
const int INDEX_TOLERANCE = 0;

const int NUMERIC_BANDS_PER_RESISTOR[6] = {-1, -1, 2, 2, 3, 3};
const int MULTIPLIER_INDEX_PER_RESISTOR[6] = {-1, -1, 2, 2, 3, 3};
const int TOLERANCE_INDEX_PER_RESISTOR[6] = {-1, -1, -1, 3, 4, 4};
const int TEMP_COEFF_INDEX_PER_RESISTOR[6] = {-1, -1, -1, -1, -1, 5};

bool has_tolerance(ResistorType rtype) {
    return TOLERANCE_INDEX_PER_RESISTOR[rtype - 1] > -1;
}

bool has_temp_coeff(ResistorType rtype) {
    return TEMP_COEFF_INDEX_PER_RESISTOR[rtype - 1] > -1;
}

bool is_numeric_band(ResistorType rtype, int index) {
    return index < NUMERIC_BANDS_PER_RESISTOR[rtype - 1];
}

bool is_multiplier_band(ResistorType rtype, int index) {
    return index == MULTIPLIER_INDEX_PER_RESISTOR[rtype - 1];
}

bool is_tolerance_band(ResistorType rtype, int index) {
    return index == TOLERANCE_INDEX_PER_RESISTOR[rtype - 1];
}

bool is_temp_coefficient_band(ResistorType rtype, int index) {
    return index == TEMP_COEFF_INDEX_PER_RESISTOR[rtype - 1];
}

bool is_numeric_colour(BandColour colour) {
    return colour <= 9;
}

bool is_multiplier_colour(BandColour colour) {
    UNUSED(colour);
    return true;
}

bool is_tolerance_colour(BandColour colour) {
    return colour == BandBrown || colour == BandRed || colour == BandOrange ||
           colour == BandYellow || colour == BandGreen || colour == BandBlue ||
           colour == BandPurple || colour == BandGray || colour == BandGold ||
           colour == BandSilver;
}

bool is_temp_coeff_colour(BandColour colour) {
    return colour == BandBrown || colour == BandRed || colour == BandOrange ||
           colour == BandYellow || colour == BandBlue || colour == BandPurple;
}

BandColour
    alter_resistor_band(ResistorType rtype, int band, BandColour current_colour, int direction) {
    int colour = current_colour;
    bool accepted = false;
    while(!accepted) {
        colour += direction;
        if(colour > 11) colour = 0;
        if(colour < 0) colour = 11;
        if(is_numeric_band(rtype, band) && is_numeric_colour(colour)) accepted = true;
        if(is_multiplier_band(rtype, band) && is_multiplier_colour(colour)) accepted = true;
        if(is_tolerance_band(rtype, band) && is_tolerance_colour(colour)) accepted = true;
        if(is_temp_coefficient_band(rtype, band) && is_temp_coeff_colour(colour)) accepted = true;
    }
    return colour;
}

int decode_resistance_number(ResistorType rtype, BandColour colours[]) {
    int bands = NUMERIC_BANDS_PER_RESISTOR[rtype - 1];
    int value = 0;
    for(int b = 0; b < bands; b++) {
        int pwr = bands - b - 1;
        int delta = ((int)pow(10.0, pwr)) * colours[b];
        value += delta;
    }
    return value;
}

void update_resistance_number(ResistorType rtype, BandColour colours[], char string[]) {
    int value = decode_resistance_number(rtype, colours);
    int length = snprintf(NULL, 0, "%d", value);
    char* str = malloc(length + 1);
    snprintf(str, length + 1, "%d", value);

    char* target = string + INDEX_NUMERIC;
    strncpy(target, str, length);
    free(str);
}

char* decode_resistance_multiplier(BandColour colour) {
    static char unit[] = "x 10^  ";
    if(colour > 9) {
        unit[5] = '-';
        unit[6] = (char)(48 + colour - 9);
    } else {
        unit[5] = (char)(48 + colour);
        unit[6] = '\0';
    }
    return unit;
}

void update_resistance_multiplier(ResistorType rtype, BandColour colours[], char string[]) {
    int multiplier_index = MULTIPLIER_INDEX_PER_RESISTOR[rtype - 1];
    char* unit = decode_resistance_multiplier(colours[multiplier_index]);
    char* target = string + INDEX_MULTIPLIER;
    strncpy(target, unit, CHARS_MULTIPLIER);
}

char* decode_resistance_tolerance(BandColour colour) {
    switch(colour) {
    case BandBrown:;
        return "1%";
    case BandRed:;
        return "2%";
    case BandOrange:;
        return "3%";
    case BandYellow:;
        return "4%";
    case BandGreen:;
        return "0.5%";
    case BandBlue:;
        return "0.25%";
    case BandPurple:;
        return "0.1%";
    case BandGray:;
        return "0.05%";
    case BandGold:;
        return "5%";
    case BandSilver:;
        return "10%";
    default:;
        return "--";
    }
}

void update_resistance_calculation(ResistorType rtype, BandColour bands[], char* string) {
    strcpy(string, BLANK_CALCULATION);
    update_resistance_number(rtype, bands, string);
    update_resistance_multiplier(rtype, bands, string);
}

void update_resistance_tolerance(ResistorType rtype, BandColour colours[], char string[]) {
    strcpy(string, BLANK_TOLERANCE);
    int tolerance_index = TOLERANCE_INDEX_PER_RESISTOR[rtype - 1];
    char* unit = decode_resistance_tolerance(colours[tolerance_index]);
    char* target = string + INDEX_TOLERANCE;
    strncpy(target, unit, CHARS_TOLERANCE);
}

char* decode_resistance_temp_coeff(BandColour colour) {
    switch(colour) {
    case BandBrown:;
        return "100";
    case BandRed:;
        return "50";
    case BandOrange:;
        return "15";
    case BandYellow:;
        return "25";
    case BandBlue:;
        return "10";
    case BandPurple:;
        return "5";
    default:;
        return "--";
    }
}

void update_resistance_temp_coeff(ResistorType rtype, BandColour colours[], char string[]) {
    strcpy(string, BLANK_TEMP_COEFF);
    int temp_coeff_index = TEMP_COEFF_INDEX_PER_RESISTOR[rtype - 1];
    char* unit = decode_resistance_temp_coeff(colours[temp_coeff_index]);
    char* target = string + INDEX_TOLERANCE;
    strncpy(target, unit, CHARS_TEMP_COEFF);
}

char* get_colour_short_description(BandColour colour) {
    switch(colour) {
    case BandBlack:
        return "Bk";
    case BandBrown:
        return "Br";
    case BandRed:
        return "Re";
    case BandOrange:
        return "Or";
    case BandYellow:
        return "Ye";
    case BandGreen:
        return "Gr";
    case BandBlue:
        return "Bl";
    case BandPurple:
        return "Pu";
    case BandGray:
        return "Gy";
    case BandWhite:
        return "Wh";
    case BandGold:
        return "Go";
    case BandSilver:
        return "Si";
    default:
        return "--";
    }
}