#include <stdlib.h>
#include <string.h>
#include <math.h>

#include "eve.h"
#include "eve_kbd.h"

#include "screen/screen.h"
#include "screen/window.h"
#include "screen/page.h"
#include "screen/font.h"

#include "label.h"
#include "widget.h"
#include "str.h"

#define CH_BS                   0x08
#define CH_DEL                  0x7f
#define CH_EOF                  0x1a

#define CH_CTRLX                0x18
#define CH_CTRLC                0x03
#define CH_CTRLV                0x16

#define STRW_TMODE_CURSOR       1
#define STRW_TMODE_SCROLL_X     2
#define STRW_TMODE_SCROLL_Y     3

#define CHAR_VALID_INPUT(c)     ((c >= 0x20) && (c < 0x7f))

void eve_strw_init(EVEStrWidget *widget, EVERect *g, EVEFont *font, char *str, uint16_t str_size) {

}

static EVEStrCursor *cursor_prox(EVEStrWidget *widget, EVEStrCursor *cursor, EVEPage *page, EVETouch *t, short *dx) {
    EVEWidget *_widget = &widget->w;
    int x = eve_page_x(page, t->x0) - _widget->g.x + widget->str_g.x;
    int _dx;

    *dx = cursor->x - x;
    _dx = *dx < 0 ? -(*dx) : *dx;

    if (_dx <= widget->font->w) return cursor;
    return NULL;
}

int eve_strw_touch(EVEWidget *_widget, EVEPage *page, uint8_t tag0, int touch_idx, EVERect *focus) {
    EVEStrWidget *widget = (EVEStrWidget *)_widget;
    EVETouch *t;
    uint16_t evt;

    if (touch_idx > 0) return 0;

    t = eve_touch_evt(tag0, touch_idx, widget->tag, 1, &evt);
    if (t && evt) {
        EVEStrCursor *t_cursor = NULL;
        short dx;
        char f = 0;

        if (evt & (EVE_TOUCH_ETYPE_LPRESS | EVE_TOUCH_ETYPE_TRACK_START)) {
            if (widget->cursor2.on) {
                t_cursor = cursor_prox(widget, &widget->cursor2, page, t, &dx);
            }
            if ((t_cursor == NULL) && widget->cursor1.on) {
                t_cursor = cursor_prox(widget, &widget->cursor1, page, t, &dx);
            }
            if (evt & EVE_TOUCH_ETYPE_TRACK_START) {
                widget->track.cursor = t_cursor;
                if (t_cursor) {
                    widget->track.mode = STRW_TMODE_CURSOR;
                    widget->track.dx = dx;
                } else if (t->eevt & EVE_TOUCH_EETYPE_TRACK_X) {
                    widget->track.mode = STRW_TMODE_SCROLL_X;
                } else if (t->eevt & EVE_TOUCH_EETYPE_TRACK_Y) {
                    widget->track.mode = STRW_TMODE_SCROLL_Y;
                }
            }
        }

        switch (widget->track.mode) {
            case STRW_TMODE_SCROLL_Y:
                if (page && page->handle_evt) page->handle_evt(page, _widget, t, evt, tag0, touch_idx);
                break;

            case STRW_TMODE_SCROLL_X:
                if (evt & EVE_TOUCH_ETYPE_TRACK_START) {
                    widget->str_g.x0 = widget->str_g.x;
                }
                if (evt & EVE_TOUCH_ETYPE_TRACK) {
                    int x = widget->str_g.x0 + t->x0 - t->x;
                    int w1 = widget->w.g.w - widget->font->w;

                    if (x < 0) x = 0;
                    if (x > widget->str_g.w - w1) x = widget->str_g.w - w1;
                    widget->str_g.x = x;
                }
                break;

            case STRW_TMODE_CURSOR:
                if (evt & EVE_TOUCH_ETYPE_TRACK) eve_strw_cursor_set(widget, widget->track.cursor, eve_page_x(page, t->x) + widget->track.dx);
                break;

            default:
                if (evt & EVE_TOUCH_ETYPE_LPRESS) {
                    if (widget->cursor2.on) {
                        // copy
                    } else if (widget->cursor1.on) {
                        if (t_cursor) {
                            // paste
                        } else {
                            eve_strw_cursor_set(widget, &widget->cursor2, eve_page_x(page, t->x));
                        }
                    } else {
                        // select
                    }
                }
                if ((evt & EVE_TOUCH_ETYPE_POINT_UP) && !(t->eevt & EVE_TOUCH_EETYPE_LPRESS)) {
                    eve_strw_cursor_set(widget, &widget->cursor1, eve_page_x(page, t->x));
                    if (widget->cursor2.on) eve_strw_cursor_clear(widget, &widget->cursor2);
                    f = 1;
                }
                break;
        }

        if (evt & EVE_TOUCH_ETYPE_TRACK_STOP) {
            widget->track.mode = 0;
            widget->track.cursor = NULL;
            widget->track.dx = 0;
        }

        if (f && focus) {
            focus->x = _widget->g.x;
            focus->y = _widget->g.y;
            focus->w = _widget->g.w;
            focus->h = 2 * widget->font->h;
        }

        return 1;
    }

    return 0;
}

uint8_t eve_strw_draw(EVEWidget *_widget, EVEPage *page, uint8_t tag0) {

}

void eve_strw_putc(void *_page, int c) {
    EVEPage *page = _page;
    EVEStrWidget *widget = (EVEStrWidget *)eve_page_get_focus(page);
    EVEStrCursor *cursor1 = &widget->cursor1;
    EVEStrCursor *cursor2 = &widget->cursor2;
    char *str;
    int w0 = widget->font->w;
    int w1 = widget->w.g.w - widget->font->w;

    if (c == CH_EOF) {
        if (cursor1->on) eve_strw_cursor_clear(widget, cursor1);
        if (cursor2->on) eve_strw_cursor_clear(widget, cursor2);
        return;
    }

    if (cursor2->on) {
        EVEStrCursor *c1;
        EVEStrCursor *c2;
        char *clipb = NULL;
        int ins_c = 0, del_c = 0;
        int ins_ch_w = 0, del_ch_w = 0;

        if (cursor1->ch <= cursor2->ch) {
            c1 = cursor1;
            c2 = cursor2;
        } else {
            c1 = cursor2;
            c2 = cursor1;
        }

        str = widget->str + c1->ch;
        del_c = c2->ch - c1->ch;
        del_ch_w = eve_font_bufw(widget->font, str, del_c);
        if ((c == CH_CTRLX) || (c == CH_CTRLC)) {
            // eve_clipb_push(str, del_c);
            if (c == CH_CTRLC) return;
        }
        if (CHAR_VALID_INPUT(c) && (widget->str_len < widget->str_size + del_c - 1)) {
            ins_c = 1;
            ins_ch_w = widget->font->w_ch[c];
        } else if (c == CH_CTRLV) {
            // clipb = eve_clipb_pop();
            ins_c = clipb ? strlen(clipb) : 0;
            if (ins_c) {
                if (widget->str_len >= widget->str_size - (ins_c - del_c)) ins_c = widget->str_size - widget->str_len + del_c - 1;
                ins_ch_w = eve_font_bufw(widget->font, clipb, ins_c);
            }
        }
        if (ins_c != del_c) memmove(str + ins_c, str + del_c, widget->str_len - c2->ch + 1);
        if (ins_c) {
            if (c == CH_CTRLV) {
                memcpy(str, clipb, ins_c);
            } else {
                *str = c;
            }
            c1->ch += ins_c;
            c1->x += ins_ch_w;
        }
        widget->str_len += ins_c - del_c;
        widget->str_g.w += ins_ch_w - del_ch_w;
        if (c1 == cursor2) widget->cursor1 = widget->cursor2;
        eve_strw_cursor_clear(widget, cursor2);
    } else if (cursor1->on) {
        uint8_t ch_w;

        str = widget->str + cursor1->ch;
        switch (c) {
            case CH_BS:
                if (cursor1->ch > 0) {
                    ch_w = widget->font->w_ch[*(str - 1)];
                    memmove(str - 1, str, widget->str_len - cursor1->ch + 1);
                    widget->str_len--;
                    widget->str_g.w -= ch_w;
                    cursor1->ch--;
                    cursor1->x -= ch_w;
                }
                break;

            case CH_DEL:
                if (cursor1->ch < widget->str_len) {
                    ch_w = widget->font->w_ch[*str];
                    memmove(str, str + 1, widget->str_len - cursor1->ch);
                    widget->str_len--;
                    widget->str_g.w -= ch_w;
                }
                break;

            default:
                if (CHAR_VALID_INPUT(c) && (widget->str_len < widget->str_size - 1)) {
                    ch_w = widget->font->w_ch[c];
                    memmove(str + 1, str, widget->str_len - cursor1->ch + 1);
                    *str = c;
                    widget->str_len++;
                    widget->str_g.w += ch_w;
                    cursor1->ch++;
                    cursor1->x += ch_w;
                }
                break;
        }
    }

    if (cursor1->x - widget->str_g.x < w0) widget->str_g.x = cursor1->x - w0 > 0 ? cursor1->x - w0 : 0;
    if (cursor1->x - widget->str_g.x > w1) widget->str_g.x = cursor1->x - w1;
}

void eve_strw_cursor_set(EVEStrWidget *widget, EVEStrCursor *cursor, int16_t x) {
    int i;
    uint16_t _x, _d;
    EVEWidget *_widget = &widget->w;

    x = x - _widget->g.x + widget->str_g.x;

    _x = 0;
    _d = x;
    for (i=0; i<widget->str_len; i++) {
        _x += widget->font->w_ch[widget->str[i]];
        if (_x >= x) {
            if (_x - x < _d) {
                i++;
            } else {
                _x -= widget->font->w_ch[widget->str[i]];
            }
            break;
        } else {
            _d = x - _x;
        }
    }
    cursor->x = _x;
    cursor->ch = i;
    cursor->on = 1;
}

void eve_strw_cursor_clear(EVEStrWidget *widget, EVEStrCursor *cursor) {
    cursor->on = 0;
}