# inventory.py

import curses

class Inventory:
    def __init__(self, cols=5, rows=4):
        self.cols = cols
        self.rows = rows
        self.slots = {i: None for i in range(cols * rows)}
        for i, ch in enumerate(["S", "H", "P"]):
            if i < cols * rows:
                self.slots[i] = ch
        self.held = None
        self.held_pos = (0, 0)

    def draw(self, stdscr, scr_w, scr_h):
        side = int(min(scr_w, scr_h) * 0.6)
        cell = (side - 2) // max(self.cols, self.rows)
        win_w = cell * self.cols + 2
        win_h = cell * self.rows + 2
        sx = (scr_w - win_w) // 2
        sy = (scr_h - win_h) // 2

        win = curses.newwin(win_h, win_w, sy, sx)
        win.bkgd(' ', curses.color_pair(3))
        win.box()

        for idx in range(self.cols * self.rows):
            r, c = divmod(idx, self.cols)
            y0 = 1 + r * cell
            x0 = 1 + c * cell
            # 绘格子
            for x in range(x0, x0+cell):
                win.addch(y0, x, curses.ACS_HLINE)
                win.addch(y0+cell-1, x, curses.ACS_HLINE)
            for y in range(y0, y0+cell):
                win.addch(y, x0, curses.ACS_VLINE)
                win.addch(y, x0+cell-1, curses.ACS_VLINE)
            win.addch(y0, x0, curses.ACS_ULCORNER)
            win.addch(y0, x0+cell-1, curses.ACS_URCORNER)
            win.addch(y0+cell-1, x0, curses.ACS_LLCORNER)
            win.addch(y0+cell-1, x0+cell-1, curses.ACS_LRCORNER)
            # 画字母
            ch = self.slots.get(idx)
            if ch:
                win.addch(y0 + cell//2, x0 + cell//2, ch, curses.color_pair(2))

        win.refresh()

        if self.held:
            my, mx = self.held_pos
            if 0 <= my < scr_h and 0 <= mx < scr_w:
                stdscr.addch(my, mx, self.held, curses.color_pair(2))
                stdscr.refresh()

        return (sy, sx, win_h, win_w)

    def click(self, my, mx, area):
        sy, sx, h, w = area
        if not (sy <= my < sy+h and sx <= mx < sx+w):
            return
        rel_y, rel_x = my-sy-1, mx-sx-1
        cell_h = (h-2)//self.rows
        cell_w = (w-2)//self.cols
        r = rel_y // cell_h
        c = rel_x // cell_w
        if 0 <= r < self.rows and 0 <= c < self.cols:
            idx = r*self.cols + c
            if self.held:
                if self.slots.get(idx) is None:
                    self.slots[idx] = self.held
                    self.held = None
            else:
                ch = self.slots.get(idx)
                if ch:
                    self.held = ch
                    self.slots[idx] = None

    def move(self, my, mx):
        self.held_pos = (my, mx)