/* Copyright 2021 James R. Maynard III <jaymaynard@gmail.com>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 <http://www.gnu.org/licenses/>.
 */
#include QMK_KEYBOARD_H

enum custom_keycodes {
    JM_DOT = SAFE_RANGE, // . both shifted and unshifted
    JM_COMM,             // , both shifted and unshifted
    JM_GRLS,             // < and > on one key
    JM_CBRC,             // { and } on one key
    JM_CENT,             // cent sign and ! on one key
    JM_DPA1,             // DUP/PA1,
    JM_FPA2,             // FldMk/PA2,
    JM_JUMP,             // JUMP/PA3,
    JM_DEL,              // Delete
    JM_NSLC              // NumLock/ScrollLock on one key
};

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
    // PC/3270 layout: PC legends (blue)
    [0] = LAYOUT(
                            KC_F13,  KC_F14,  KC_F15,  KC_F16,  KC_F17,  KC_F18,  KC_F19,  KC_F20,  KC_F21,  KC_F22,   KC_F23,  KC_F24,
                            KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,   KC_F11,  KC_F12,

        KC_NO,   KC_NO,     KC_GRV,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_6,    KC_7,    KC_8,    KC_9,     KC_0,    KC_MINS, KC_EQL,  KC_BSPC,   KC_NO,   KC_PGUP, KC_PGDN,    KC_ESC,  JM_NSLC, KC_PAST, KC_PSLS,
        KC_NO,   KC_PAUS,   KC_TAB,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,    KC_Y,    KC_U,    KC_I,    KC_O,     KC_P,    KC_LBRC, KC_RBRC, KC_ENT,    KC_END,  KC_INS,  KC_DEL,     KC_P7,   KC_P8,   KC_P9,   KC_PPLS,
        KC_NO,   KC_NO,     KC_CAPS, KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    KC_H,    KC_J,    KC_K,    KC_L,     KC_SCLN, KC_QUOT, KC_BSLS,                     KC_UP,               KC_P4,   KC_P5,   KC_P6,   KC_PMNS,
        KC_PSCR, KC_NO,     KC_LSFT, JM_GRLS, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_N,    KC_M,    KC_COMM,  KC_DOT,  KC_SLSH, KC_RSFT,            KC_LEFT, KC_HOME, KC_RIGHT,   KC_P1,   KC_P2,   KC_P3,   KC_PENT,
        MO(2),   KC_LGUI,   KC_LCTL, KC_LALT,                                     KC_SPC,                                       KC_RALT, KC_RCTL,                     KC_DOWN,             KC_P0,            KC_PDOT
    ),

    // PC/3270 layout: 3270 legends (black), with x3270 keycodes
    [1] = LAYOUT(
                             A(KC_F1), A(KC_F2), A(KC_F3), A(KC_F4), A(KC_F5), A(KC_F6), A(KC_F7), A(KC_F8), A(KC_F9), A(KC_F10), A(KC_F11), A(KC_F12),
                             KC_F1,    KC_F2,    KC_F3,    KC_F4,    KC_F5,    KC_F6,    KC_F7,    KC_F8,    KC_F9,    KC_F10,    KC_F11,    KC_F12,

        A(KC_A),  A(KC_C),   KC_GRV,   KC_1,     KC_2,     KC_3,     KC_4,     KC_5,     KC_6,     KC_7,     KC_8,     KC_9,      KC_0,      KC_MINS,   KC_EQL,  KC_BSPC,   JM_DPA1,   JM_FPA2, JM_JUMP,    KC_ESC,  JM_NSLC, KC_PCMM, KC_SPC,
        KC_CRSEL, KC_PAUS,   KC_TAB,   KC_Q,     KC_W,     KC_E,     KC_R,     KC_T,     KC_Y,     KC_U,     KC_I,     KC_O,      KC_P,      JM_CENT,   KC_BSLS, S(KC_ENT), S(KC_TAB), KC_INS,  JM_DEL,     KC_P7,   KC_P8,   KC_P9,   KC_TAB,
        KC_EXSEL, A(KC_E),   KC_CAPS,  KC_A,     KC_S,     KC_D,     KC_F,     KC_G,     KC_H,     KC_J,     KC_K,     KC_L,      KC_SCLN,   KC_QUOT,   JM_CBRC,                       KC_UP,               KC_P4,   KC_P5,   KC_P6,   KC_PMNS,
        A(KC_B),  C(KC_C),   KC_LSFT,  JM_GRLS,  KC_Z,     KC_X,     KC_C,     KC_V,     KC_B,     KC_N,     KC_M,     JM_COMM,   JM_DOT,    KC_SLSH,   KC_RSFT,            KC_LEFT,   A(KC_H), KC_RIGHT,   KC_P1,   KC_P2,   KC_P3,   KC_PENT,
        MO(2),    KC_LGUI,   A(KC_R),  KC_LALT,                                          KC_SPC,                                             KC_RALT,   KC_ENT,                        KC_DOWN,             KC_P0,            KC_PDOT
    ),

    // Function layer, accessed by the Zoom key
    [2] = LAYOUT(
                            _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
                            _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,

        DF(0),   DF(1),     _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,   _______, _______, _______,   _______, _______, _______, _______,
        _______, _______,   _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,   _______, _______, _______,   _______, _______, _______, _______,
        _______, _______,   _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,                     _______,            _______, _______, _______, _______,
        _______, _______,   _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,            _______, _______, _______,   _______, _______, _______, _______,
        _______, _______,   _______, _______,                                     MO(3),                                       _______, _______,                     _______,            _______,          _______
    ),

    // Firmware layer, accessed by the Zoom/Space key pair (hold both down)
    [3] = LAYOUT(
                            _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
                            _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,

        _______, _______,   _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,   _______, _______, _______,   _______, _______, _______, _______,
        _______, _______,   _______, _______, _______, EE_CLR,  QK_BOOT, _______, _______, _______, _______, _______, _______, _______, _______, _______,   _______, _______, _______,   _______, _______, _______, _______,
        _______, _______,   _______, _______, _______, DB_TOGG, _______, _______, _______, _______, _______, _______, _______, _______, _______,                     _______,            _______, _______, _______, _______,
        _______, _______,   _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,            _______, _______, _______,   _______, _______, _______, _______,
        _______, _______,   _______, _______,                                              _______,                            _______, _______,                     _______,            _______,          _______
    )
};

bool left_shift_down = false;
bool right_shift_down = false;
bool left_alt_down = false;
bool right_alt_down = false;

bool process_record_user(uint16_t keycode, keyrecord_t *record) {
    switch (keycode) {
        case KC_LSFT:
            left_shift_down = record->event.pressed;
            break;
        case KC_RSFT:
            right_shift_down = record->event.pressed;
            break;
        case KC_LALT:
            left_alt_down = record->event.pressed;
            break;
        case KC_RALT:
            right_alt_down = record->event.pressed;
            break;
        case JM_GRLS:
            if (left_shift_down || right_shift_down) {
                if(record->event.pressed) {
                    SEND_STRING(">");
                }
            } else {
                if(record->event.pressed) {
                    SEND_STRING("<");
                }
            }
            return false;
        case JM_CBRC:
            if (left_shift_down || right_shift_down) {
                if (record->event.pressed) {
                    SEND_STRING("}");
                }
            } else {
                if(record->event.pressed) {
                    SEND_STRING("{");
                }
            }
            return false;
        case JM_CENT:
            if (left_shift_down || right_shift_down) {
                if (record->event.pressed) {
                    SEND_STRING("!");
                }
            } else {    // This assumes that the Linux Compose has been set to Scroll Lock
                if (record->event.pressed) {
                    tap_code16(KC_SCRL);
                    SEND_STRING("c/");
                }
            }
            return false;
        case JM_COMM:
            if (record->event.pressed){
                SEND_STRING(",");
            }
            return false;
        case JM_DOT:
            if (record->event.pressed) {
                SEND_STRING(".");
            }
            return false;
        case JM_DPA1:
            if (left_shift_down || right_shift_down) {
                if (record->event.pressed) {
                    tap_code16(C(KC_D));
                }
                return false;
            } else {
                if(record->event.pressed) {
                    tap_code16(A(KC_1));
                }
                return false;
            }
            break;
        case JM_FPA2:
            if (left_shift_down || right_shift_down) {
                if (record->event.pressed) {
                    tap_code16(C(KC_F));
                }
                return false;
            } else {
                if(record->event.pressed) {
                    tap_code16(A(KC_2));
                }
                return false;
            }
            break;
        case JM_JUMP:
            if (record->event.pressed) {
                if (left_alt_down || right_alt_down) {
                    SEND_STRING("3");
                }
            }
            return false;
        case JM_DEL:
            if (record->event.pressed) {
                if (left_alt_down || right_alt_down) {
                    unregister_code(KC_LALT);
                    unregister_code(KC_RALT);
                    tap_code16(C(KC_W));
                    if (left_alt_down) {
                        register_code(KC_LALT);
                    }
                    if (right_alt_down) {
                        register_code(KC_RALT);
                    }
                } else {
                    tap_code16(KC_DEL);
                }
            }
            return false;
        case JM_NSLC:
            if (left_shift_down || right_shift_down) {
                if (record->event.pressed) {
                    register_code(KC_NUM_LOCK);
                }
                else {
                    unregister_code(KC_NUM_LOCK);
                }
            } else {
                if (record->event.pressed) {
                    register_code(KC_SCRL);
                }
                else {
                    unregister_code(KC_SCRL);
                }
            }
            return false;
    }

    return true;
}
