// One app-wide snackbar, mounted once in the root layout. `showToast` is a
// plain function so stores and rows can call it without a context hop. A new
// toast replaces the current one (last action wins) and the timer restarts.
import { useEffect, useState } from "react";
import { Pressable, StyleSheet, Text } from "react-native";
import Animated, { FadeInDown, FadeOutDown } from "react-native-reanimated";
import { useSafeAreaInsets } from "react-native-safe-area-context";
import { haptic } from "../lib/haptics";
import { C, radius, shadow, space, type } from "../lib/theme";

export interface ToastSpec {
  message: string;
  action?: { label: string; onPress: () => void };
}

const DURATION_MS = 5000;
// Sits on the home FAB's baseline (index.tsx `fab.bottom`) — above the
// launcher bar, and the right padding leaves the FAB itself uncovered.
const FAB_BOTTOM = 104;
const FAB_CLEARANCE = space.xl + 56 + space.md;

let setCurrent: ((t: ToastSpec | null) => void) | null = null;

export function showToast(spec: ToastSpec) {
  setCurrent?.(spec);
}

export function ToastHost() {
  const [toast, setToast] = useState<ToastSpec | null>(null);
  const insets = useSafeAreaInsets();

  useEffect(() => {
    setCurrent = setToast;
    return () => {
      if (setCurrent === setToast) setCurrent = null;
    };
  }, []);

  useEffect(() => {
    if (!toast) return;
    const timer = setTimeout(() => setToast(null), DURATION_MS);
    return () => clearTimeout(timer);
  }, [toast]);

  if (!toast) return null;
  const { action } = toast;
  return (
    <Animated.View
      entering={FadeInDown.duration(180)}
      exiting={FadeOutDown.duration(150)}
      style={[s.wrap, { bottom: FAB_BOTTOM + insets.bottom }]}
      pointerEvents="box-none"
    >
      <Pressable style={s.toast} onPress={() => setToast(null)}>
        <Text style={s.message} numberOfLines={1}>
          {toast.message}
        </Text>
        {action && (
          <Pressable
            hitSlop={12}
            onPress={() => {
              haptic.tap();
              setToast(null);
              action.onPress();
            }}
            style={({ pressed }) => [s.action, pressed && { opacity: 0.6 }]}
          >
            <Text style={s.actionText}>{action.label}</Text>
          </Pressable>
        )}
      </Pressable>
    </Animated.View>
  );
}

const s = StyleSheet.create({
  wrap: {
    position: "absolute",
    left: space.lg,
    right: FAB_CLEARANCE,
    alignItems: "flex-start",
  },
  toast: {
    flexDirection: "row",
    alignItems: "center",
    gap: space.lg,
    maxWidth: 420,
    paddingVertical: space.md,
    paddingLeft: space.lg,
    paddingRight: space.md,
    borderRadius: radius.pill,
    backgroundColor: C.text,
    ...shadow.fab,
  },
  message: { ...type.row, color: C.bg, flexShrink: 1 },
  action: { paddingVertical: space.xs, paddingHorizontal: space.sm },
  actionText: { ...type.row, color: C.accentSoft, fontWeight: "600" },
});