#include "tim.h"


void TimEditState_init(TimEditState* e, i32 capacity, cstr initial_content){
    e->length = tim_utf8_len(initial_content);
    e->cursor = tim_utf8_len(initial_content);
    e->capacity = capacity;
    e->s = (char*)malloc(capacity + 1);
    i32 byte_len = strlen(initial_content);
    memcpy(e->s, initial_content, byte_len);
    e->s[byte_len] = 0;
}

void TimEditState_insert(TimEditState* e, cstr s) {
    i32 dst_size = tim_ztrlen(e->s);
    i32 src_size = tim_ztrlen(s);
    if (dst_size + src_size < e->capacity) {
        i32 len = tim_utf8_len(s); // usually 1, except when smashing keys
        i32 cur = tim_utf8_pos(e->s, e->cursor);
        memmove(e->s + cur + src_size, e->s + cur, dst_size - cur);
        memmove(e->s + cur, s, src_size);
        e->s[dst_size + src_size] = 0;
        e->length += len;
        e->cursor += len;
    }
}

void TimEditState_delete(TimEditState* e) {
    i32 size = tim_ztrlen(e->s);
    i32 cur  = tim_utf8_pos(e->s, e->cursor);
    i32 len  = tim_utf8_pos(e->s + cur, 1);
    if (size - cur > 0) {
        memmove(e->s + cur, e->s + cur + len, size - cur);
        e->length -= 1;
    }
}

/// @return key id or 0
static TimKey edit_event(TimEditState* e, TimRect r) {
    if (tim_is_mouse_click_over(r)) {
        // take focus
        tim->focus = e;
        return 0;
    }

    if (tim->focus != e || tim->event.type != TimEvent_Key) {
        // not focused or no key press
        return 0;
    }
    tim->event.type = TimEvent_Void; // consume event

    switch (tim->event.key) {
    case TimKey_Escape:
    case TimKey_Enter:
        tim->focus = 0; // release focus
        break;
    case TimKey_Delete:
        TimEditState_delete(e);
        break;
    case TimKey_Backspace:
        if (e->cursor > 0) {
            e->cursor -= 1;
            TimEditState_delete(e);
        }
        break;
    case TimKey_Left:
        e->cursor -= (e->cursor > 0);
        break;
    case TimKey_Right:
        e->cursor += (e->cursor < e->length);
        break;
    case TimKey_Home:
        e->cursor = 0;
        break;
    case TimKey_End:
        e->cursor = e->length;
        break;
    default:
        if (tim->event.key >= ' ') {
            TimEditState_insert(e, tim->event.s);
        }
        break;
    }

    return tim->event.key;
}

TimKey tim_edit(TimEditState* e, i32 x, i32 y, i32 w, u64 color) {
    TimRect r = tim_scope_rect_to_absolute(x, y, w, 3);

    if (tim->event.type == TimEvent_Draw) {
        tim_draw_box(r.x, r.y, r.w, r.h, color >> 16, color >> 8);
        if (tim->focus == e) {
            char* s = e->s + tim_utf8_pos(e->s, e->cursor - r.w + 4);
            i32   cur = MIN(r.w - 4, e->cursor);
            tim_draw_str(s, r.x + 2, r.y + 1, r.w - 3, color, color >> 8);
            tim_draw_invert(r.x + cur + 2, r.y + 1, 1);
        } else {
            tim_draw_str(e->s, r.x + 2, r.y + 1, r.w - 3, color, color >> 8);
        }
    }

    return edit_event(e, r);
}