import {

  View,

  StyleSheet,

  KeyboardAvoidingView,

  ScrollView,

  TouchableOpacity,

  ActivityIndicator,

} from "react-native";

import { Text } from "@/components/ui/Text";

import { useEffect, useState } from "react";

import { router, useLocalSearchParams } from "expo-router";

import { Card } from "@/components/ui/Cards";

import { Input } from "@/components/ui/Input";

import { Button } from "@/components/ui/Button";

import { Section, SectionHeader } from "@/components/ui/Sections";

import { Spacing, Typography, Colors, BorderRadius } from "@/constants/theme";

import { TimePicker } from "@/components/ui/TimePicker";

import { useMedicineRegimen, useUpdateMedicineRegimen } from "@/hooks";

import { MedicinePeriodicity } from "@/lib/api";

const PERIODICITY_OPTIONS: { label: string; value: MedicinePeriodicity }[] = [

  { label: "Uma vez", value: "ONCE" },

  { label: "Diário", value: "DAILY" },

  { label: "2x ao dia", value: "TWICE_DAILY" },

  { label: "3x ao dia", value: "THREE_TIMES_DAILY" },

  { label: "Semanal", value: "WEEKLY" },

  { label: "Quinzenal", value: "BIWEEKLY" },

  { label: "Mensal", value: "MONTHLY" },

];

function getTimePickerCount(p: MedicinePeriodicity): number {

  switch (p) {

    case "ONCE": return 0;

    case "DAILY": return 1;

    case "TWICE_DAILY": return 2;

    case "THREE_TIMES_DAILY": return 3;

    default: return 1;

  }

}

function timesToDates(times: string[]): Date[] {

  return times.map((t) => {

    const [h, m] = t.split(":").map(Number);

    const d = new Date();

    d.setHours(h, m, 0, 0);

    return d;

  });

}

export default function MedicineRegimenEdit() {

  const { id } = useLocalSearchParams<{ id: string }>();

  const { data, isLoading } = useMedicineRegimen(id);

  const updateRegimen = useUpdateMedicineRegimen();

  const [name, setName] = useState("");

  const [dosage, setDosage] = useState("");

  const [periodicity, setPeriodicity] = useState<MedicinePeriodicity>("DAILY");

  const [scheduledTimes, setScheduledTimes] = useState<Date[]>([]);

  const [initialized, setInitialized] = useState(false);

  useEffect(() => {

    if (data?.regimen && !initialized) {

      const r = data.regimen;

      setName(r.name);

      setDosage(r.dosage);

      setPeriodicity(r.periodicity as MedicinePeriodicity);

      setScheduledTimes(timesToDates(r.scheduledAt));

      setInitialized(true);

    }

  }, [data, initialized]);

  const handleSave = async () => {

    const count = getTimePickerCount(periodicity);

    const scheduledAt = scheduledTimes.slice(0, count).map(

      (d) =>

        `${d.getHours().toString().padStart(2, "0")}:${d.getMinutes().toString().padStart(2, "0")}`

    );

    await updateRegimen.mutateAsync({

      id,

      payload: { name, dosage, periodicity, scheduledAt },

    });

    router.back();

  };

  if (isLoading || !initialized) {

    return (

      <View style={styles.center}>

        <ActivityIndicator color={Colors.light.tint} />

      </View>

    );

  }

  return (

    <KeyboardAvoidingView behavior="height" style={styles.keyboardView}>

      <ScrollView scrollEventThrottle={16}>

        <View style={styles.container}>

          <View style={styles.header}>

            <Text style={styles.headerTitle}>Editar medicamento</Text>

            <Text style={styles.headerSubtitle}>

              Atualize os detalhes do medicamento

            </Text>

          </View>

          <Section>

            <SectionHeader title="Detalhes" />

            <Card style={{ padding: Spacing.cardGap }}>

              <Input

                label="Nome"

                value={name}

                onChangeText={setName}

                placeholder="Ex: Fluoxetina"

                variant="darkGhost"

              />

              <Input

                label="Dosagem"

                value={dosage}

                onChangeText={setDosage}

                placeholder="Ex: 20mg"

                variant="darkGhost"

              />

            </Card>

          </Section>

          <Section>

            <SectionHeader title="Frequência" />

            <View style={styles.periodicityRow}>

              {PERIODICITY_OPTIONS.map((opt) => (

                <TouchableOpacity

                  key={opt.value}

                  style={[

                    styles.periodicityChip,

                    periodicity === opt.value && styles.periodicityChipActive,

                  ]}

                  onPress={() => {

                    setPeriodicity(opt.value);

                    const count = getTimePickerCount(opt.value);

                    setScheduledTimes((prev) =>

                      count === 0

                        ? []

                        : count > prev.length

                        ? [...prev, ...Array(count - prev.length).fill(new Date())]

                        : prev.slice(0, count)

                    );

                  }}

                  activeOpacity={0.7}

                >

                  <Text

                    style={[

                      styles.periodicityChipLabel,

                      periodicity === opt.value && styles.periodicityChipLabelActive,

                    ]}

                  >

                    {opt.label}

                  </Text>

                </TouchableOpacity>

              ))}

            </View>

          </Section>

          {scheduledTimes.length > 0 && (

            <Section>

              <SectionHeader

                title={scheduledTimes.length === 1 ? "Horário" : "Horários"}

              />

              {scheduledTimes.map((t, i) => (

                <View style={{ marginTop: 10 }} key={i}>

                  <TimePicker

                    value={t}

                    onChange={(date) =>

                      setScheduledTimes((prev) =>

                        prev.map((v, idx) => (idx === i ? date : v))

                      )

                    }

                  />

                </View>

              ))}

            </Section>

          )}

          <Button

            title="Salvar"

            onPress={handleSave}

            loading={updateRegimen.isPending}

            disabled={!name || !dosage}

          />

        </View>

      </ScrollView>

    </KeyboardAvoidingView>

  );

}

const styles = StyleSheet.create({

  keyboardView: { flex: 1 },

  center: { flex: 1, alignItems: "center", justifyContent: "center" },

  container: {

    gap: 24,

    paddingHorizontal: Spacing.containerPadding,

    paddingVertical: Spacing.sectionGap,

    marginBottom: 50,

  },

  header: { gap: 8 },

  headerTitle: { ...Typography.headlineMd },

  headerSubtitle: {

    ...Typography.bodyMd,

    color: Colors.light.textSecondary,

  },

  periodicityRow: {

    flexDirection: "row",

    flexWrap: "wrap",

    gap: 8,

  },

  periodicityChip: {

    paddingHorizontal: 16,

    paddingVertical: 10,

    borderRadius: BorderRadius.full,

    backgroundColor: "#fff",

    borderWidth: 1.5,

    borderColor: Colors.light.divider,

  },

  periodicityChipActive: {

    backgroundColor: Colors.light.tint + "1A",

    borderColor: Colors.light.tint,

  },

  periodicityChipLabel: {

    fontSize: 14,

    fontWeight: "500",

    color: Colors.light.text,

  },

  periodicityChipLabelActive: {

    fontWeight: "600",

    color: Colors.light.text,

  },

});