Initial commit

components/actress/ActressSelectionProvider.tsx

@@ -0,0 +1,97 @@
+"use client";
+import { createContext, useCallback, useContext, useMemo, useState } from "react";
+
+type Ctx = {
+  ids: Set<number>;
+  has: (id: number) => boolean;
+  toggle: (id: number) => void;
+  selectMany: (ids: number[]) => void;
+  setMany: (ids: number[]) => void;
+  selectRangeTo: (id: number, orderedIds: number[]) => void;
+  clear: () => void;
+  lastClickedId: number | null;
+};
+
+const ActressSelectCtx = createContext<Ctx | null>(null);
+
+export function ActressSelectionProvider({ children }: { children: React.ReactNode }) {
+  const [ids, setIds] = useState<Set<number>>(new Set());
+  const [lastClickedId, setLastClickedId] = useState<number | null>(null);
+
+  const toggle = useCallback((id: number) => {
+    setIds((cur) => {
+      const next = new Set(cur);
+      if (next.has(id)) next.delete(id); else next.add(id);
+      return next;
+    });
+    setLastClickedId(id);
+  }, []);
+
+  const selectMany = useCallback((newIds: number[]) => {
+    setIds((cur) => {
+      const next = new Set(cur);
+      newIds.forEach((i) => next.add(i));
+      return next;
+    });
+  }, []);
+
+  const setMany = useCallback((newIds: number[]) => {
+    setIds(new Set(newIds));
+  }, []);
+
+  const selectRangeTo = useCallback((id: number, orderedIds: number[]) => {
+    const last = lastClickedId;
+    if (last == null) {
+      setIds((cur) => {
+        const next = new Set(cur);
+        next.add(id);
+        return next;
+      });
+      setLastClickedId(id);
+      return;
+    }
+    const a = orderedIds.indexOf(last);
+    const b = orderedIds.indexOf(id);
+    if (a === -1 || b === -1) {
+      setIds((cur) => {
+        const next = new Set(cur);
+        next.add(id);
+        return next;
+      });
+      setLastClickedId(id);
+      return;
+    }
+    const [start, end] = a < b ? [a, b] : [b, a];
+    const range = orderedIds.slice(start, end + 1);
+    setIds((cur) => {
+      const next = new Set(cur);
+      range.forEach((i) => next.add(i));
+      return next;
+    });
+    setLastClickedId(id);
+  }, [lastClickedId]);
+
+  const clear = useCallback(() => {
+    setIds(new Set());
+    setLastClickedId(null);
+  }, []);
+
+  const value = useMemo<Ctx>(() => ({
+    ids,
+    has: (id) => ids.has(id),
+    toggle,
+    selectMany,
+    setMany,
+    selectRangeTo,
+    clear,
+    lastClickedId,
+  }), [ids, toggle, selectMany, setMany, selectRangeTo, clear, lastClickedId]);
+
+  return <ActressSelectCtx.Provider value={value}>{children}</ActressSelectCtx.Provider>;
+}
+
+export function useActressSelection() {
+  const ctx = useContext(ActressSelectCtx);
+  if (!ctx) throw new Error("useActressSelection must be used within ActressSelectionProvider");
+  return ctx;
+}