import { GROUP_MEMBER_MAX, GROUP_MEMBER_MIN } from "@rakazo/contracts";
import { Stack, useLocalSearchParams, useRouter } from "expo-router";
import { useEffect, useState } from "react";
import { Alert, Pressable, ScrollView, Text, TextInput } from "react-native";
import { BotMemberPicker } from "../components/bot-member-picker";
import {
  type MobileBot,
  type MobileGroup,
  type MobileSpace,
  type MobileSpaceNavigation,
  rpc,
} from "../lib/api";
import { useI18n } from "../lib/i18n";
import { canDeleteInboxSpace, removeInboxSpace } from "../lib/inbox-spaces";
import { useMobileTokens } from "../lib/native";

export default function GroupSettingsScreen() {
  const { t } = useI18n();
  const tokens = useMobileTokens();
  const router = useRouter();
  const { groupId } = useLocalSearchParams<{ groupId: string }>();
  const [group, setGroup] = useState<MobileGroup | null>(null);
  const [projectSpace, setProjectSpace] = useState<MobileSpace | null>(null);
  const [bots, setBots] = useState<MobileBot[]>([]);
  const [name, setName] = useState("");
  const [selected, setSelected] = useState<string[]>([]);
  const [error, setError] = useState<string | null>(null);
  const [pending, setPending] = useState(false);

  const isMainConversation = group?.kind === "main";
  const isProjectMain = isMainConversation && projectSpace !== null && !projectSpace.isDefault;

  useEffect(() => {
    if (!groupId) return;
    void Promise.all([
      rpc<MobileGroup[]>("groups/list").then(
        (groups) => groups.find((row) => row.id === groupId) ?? null,
      ),
      rpc<MobileBot[]>("bots/list"),
      rpc<MobileSpaceNavigation>("spaces/list").catch(() => null),
    ])
      .then(([nextGroup, nextBots, navigation]) => {
        if (!nextGroup) throw new Error(t("Group not found"));
        setGroup(nextGroup);
        const space =
          navigation?.spaces.find(
            (item) => item.id === nextGroup.spaceId || item.id === navigation.current.id,
          ) ?? null;
        setProjectSpace(space);
        setName(
          nextGroup.kind === "main" && space && !space.isDefault ? space.name : nextGroup.name,
        );
        setSelected(nextGroup.members.map((member) => member.botId));
        setBots(nextBots.filter((bot) => !bot.archivedAt));
      })
      .catch((err) => setError(err instanceof Error ? err.message : t("Could not load group")));
  }, [groupId]);

  async function save() {
    if (!groupId || !group || pending) return;
    setPending(true);
    setError(null);
    try {
      const trimmed = name.trim();
      if (isProjectMain && projectSpace) {
        if (trimmed && trimmed !== projectSpace.name) {
          await rpc("spaces/update", { spaceId: projectSpace.id, name: trimmed });
        }
        router.back();
        return;
      }
      const input: { groupId: string; name?: string; botIds?: string[] } = { groupId };
      if (trimmed !== group.name) input.name = trimmed;
      if (!isMainConversation) {
        const memberIds = group.members.map((member) => member.botId).join(",");
        if (selected.join(",") !== memberIds) input.botIds = selected;
      }
      if (input.name || input.botIds) await rpc("groups/update", input);
      router.back();
    } catch (err) {
      setError(err instanceof Error ? err.message : t("Could not save group"));
    } finally {
      setPending(false);
    }
  }

  function remove() {
    if (!groupId || !group) return;
    if (isProjectMain && projectSpace) {
      Alert.alert(
        t("Delete {name}?", { name: projectSpace.name }),
        t("This removes the empty space for everyone."),
        [
          { text: t("Cancel"), style: "cancel" },
          {
            text: t("Delete"),
            style: "destructive",
            onPress: () =>
              void removeInboxSpace(projectSpace.id, async () => {})
                .then(() => router.replace("/"))
                .catch((err) =>
                  Alert.alert(
                    t("Could not delete space"),
                    err instanceof Error ? err.message : t("Try again."),
                  ),
                ),
          },
        ],
      );
      return;
    }
    Alert.alert(group.name, t("Delete this group? Bots and their solo threads are kept."), [
      { text: t("Cancel"), style: "cancel" },
      {
        text: t("Delete"),
        style: "destructive",
        onPress: () =>
          void rpc("groups/remove", { groupId })
            .then(() => router.replace("/"))
            .catch((err) =>
              Alert.alert(
                t("Could not delete group"),
                err instanceof Error ? err.message : t("Try again."),
              ),
            ),
      },
    ]);
  }

  const saveDisabled =
    !name.trim() ||
    pending ||
    (!isMainConversation &&
      (selected.length < GROUP_MEMBER_MIN || selected.length > GROUP_MEMBER_MAX));

  return (
    <>
      <Stack.Screen options={{ title: t("Group settings") }} />
      <ScrollView
        style={{ flex: 1, backgroundColor: tokens.background }}
        contentContainerStyle={{ padding: 24 }}
      >
        <Text style={{ color: tokens.mutedForeground, fontSize: 14 }}>{t("Name")}</Text>
        <TextInput
          value={name}
          onChangeText={setName}
          placeholder={t("Group name")}
          placeholderTextColor={tokens.mutedForeground}
          style={{
            marginTop: 8,
            backgroundColor: tokens.muted,
            borderRadius: 11,
            padding: 14,
            color: tokens.foreground,
            fontSize: 16,
          }}
        />
        {!isMainConversation ? (
          <>
            <Text style={{ color: tokens.mutedForeground, fontSize: 14, marginTop: 20 }}>
              {t("Members")}
            </Text>
            <BotMemberPicker
              bots={bots}
              selected={selected}
              onChange={setSelected}
              disabled={pending}
            />
          </>
        ) : null}
        {error ? <Text style={{ color: tokens.destructive, marginTop: 12 }}>{error}</Text> : null}
        <Pressable
          onPress={() => void save()}
          disabled={saveDisabled}
          style={{
            marginTop: 24,
            backgroundColor: tokens.primary,
            opacity: saveDisabled ? 0.5 : 1,
            borderRadius: 11,
            padding: 14,
            alignItems: "center",
          }}
        >
          <Text style={{ color: tokens.primaryForeground, fontSize: 16, fontWeight: "600" }}>
            {pending ? t("Saving…") : t("Save")}
          </Text>
        </Pressable>
        {isProjectMain && projectSpace && canDeleteInboxSpace(projectSpace) ? (
          <Pressable
            onPress={remove}
            style={{
              marginTop: 16,
              borderRadius: 11,
              borderWidth: 1,
              borderColor: tokens.border,
              padding: 14,
              alignItems: "center",
            }}
          >
            <Text style={{ color: tokens.destructive, fontSize: 16 }}>{t("Delete space")}</Text>
          </Pressable>
        ) : !isMainConversation ? (
          <Pressable
            onPress={remove}
            style={{
              marginTop: 16,
              borderRadius: 11,
              borderWidth: 1,
              borderColor: tokens.border,
              padding: 14,
              alignItems: "center",
            }}
          >
            <Text style={{ color: tokens.destructive, fontSize: 16 }}>{t("Delete group")}</Text>
          </Pressable>
        ) : null}
      </ScrollView>
    </>
  );
}