import { useState } from "react";
import { View, Text, TextInput, Pressable, ScrollView, Alert } from "react-native";
import { useNavigation } from "@react-navigation/native";
import type { NativeStackNavigationProp } from "@react-navigation/native-stack";
import type { RootStackParamList } from "@navigation/types";
import { useWorkoutBuilder } from "../hooks/useWorkoutBuilder";
import { useSettings } from "../../../providers/WatchProvider";
import type { StrokeType } from "@types/workout";

const STROKES: StrokeType[] = ["Freestyle", "Backstroke", "Breaststroke", "Butterfly", "Mixed"];

export function BuilderScreen() {
  const navigation = useNavigation<NativeStackNavigationProp<RootStackParamList>>();
  const { poolLength: defaultPoolLength } = useSettings();
  const [poolLength, setPoolLength] = useState(defaultPoolLength);
  const {
    sets,
    workoutName,
    setWorkoutName,
    totalDistance,
    isSaving,
    addSet,
    updateSet,
    removeSet,
    save,
  } = useWorkoutBuilder();

  const handleSave = async () => {
    try {
      const workoutId = await save(poolLength);
      navigation.navigate("PreSwim", { workoutId });
    } catch (e) {
      console.error("Failed to save workout:", e);
      Alert.alert("Error", `Failed to save workout: ${e}`);
    }
  };

  return (
    <ScrollView className="flex-1 bg-white">
      <View className="p-4">
        <Text className="text-2xl font-bold text-slate-900 mb-1">Build Workout</Text>
        <Text className="text-slate-500 mb-4">
          {totalDistance}m total · {poolLength}m pool
        </Text>

        <View className="mb-4">
          <Text className="text-sm font-medium text-slate-500 mb-1">Workout Name</Text>
          <TextInput
            value={workoutName}
            onChangeText={setWorkoutName}
            placeholder="Morning Swim"
            placeholderTextColor="#94a3b8"
            className="bg-slate-50 border border-slate-200 rounded-xl px-4 py-3 text-slate-900"
          />
        </View>

        <View className="mb-4">
          <Text className="text-sm font-medium text-slate-500 mb-1">Pool Length</Text>
          <View className="flex-row gap-2">
            {[25, 50].map((length) => (
              <Pressable
                key={length}
                onPress={() => setPoolLength(length)}
                className={`flex-1 py-2.5 rounded-xl items-center ${
                  poolLength === length ? "bg-sky-500" : "bg-slate-100"
                }`}
              >
                <Text
                  className={`font-semibold ${
                    poolLength === length ? "text-white" : "text-slate-600"
                  }`}
                >
                  {length}m
                </Text>
              </Pressable>
            ))}
          </View>
        </View>

        {sets.map((set, index) => (
          <View key={index} className="bg-slate-50 rounded-2xl p-4 mb-3 border border-slate-200">
            <View className="flex-row justify-between items-center mb-3">
              <Text className="font-semibold text-slate-700">Set {index + 1}</Text>
              {sets.length > 1 && (
                <Pressable onPress={() => removeSet(index)}>
                  <Text className="text-red-500 text-sm font-medium">Remove</Text>
                </Pressable>
              )}
            </View>

            <Text className="text-xs font-medium text-slate-500 mb-1.5 uppercase tracking-wide">
              Stroke
            </Text>
            <ScrollView horizontal showsHorizontalScrollIndicator={false} className="mb-3">
              {STROKES.map((stroke) => (
                <Pressable
                  key={stroke}
                  onPress={() => updateSet(index, { stroke })}
                  className={`mr-2 px-3 py-1.5 rounded-full ${
                    set.stroke === stroke ? "bg-sky-500" : "bg-slate-200"
                  }`}
                >
                  <Text
                    className={`text-xs font-medium ${
                      set.stroke === stroke ? "text-white" : "text-slate-600"
                    }`}
                  >
                    {stroke}
                  </Text>
                </Pressable>
              ))}
            </ScrollView>

            <View className="flex-row gap-2">
              <View className="flex-1">
                <Text className="text-xs font-medium text-slate-500 mb-1">Distance (m)</Text>
                <TextInput
                  keyboardType="numeric"
                  value={String(set.distancePerRep)}
                  onChangeText={(t) => updateSet(index, { distancePerRep: Number(t) || 0 })}
                  className="bg-white border border-slate-300 rounded-lg px-3 py-2 text-slate-900"
                />
              </View>
              <View className="flex-1">
                <Text className="text-xs font-medium text-slate-500 mb-1">Reps</Text>
                <TextInput
                  keyboardType="numeric"
                  value={String(set.repCount)}
                  onChangeText={(t) => updateSet(index, { repCount: Number(t) || 1 })}
                  className="bg-white border border-slate-300 rounded-lg px-3 py-2 text-slate-900"
                />
              </View>
              <View className="flex-1">
                <Text className="text-xs font-medium text-slate-500 mb-1">Rest (s)</Text>
                <TextInput
                  keyboardType="numeric"
                  value={String(set.restDuration)}
                  onChangeText={(t) => updateSet(index, { restDuration: Number(t) || 0 })}
                  className="bg-white border border-slate-300 rounded-lg px-3 py-2 text-slate-900"
                />
              </View>
            </View>
          </View>
        ))}

        <Pressable
          onPress={addSet}
          className="bg-slate-100 rounded-2xl py-3 items-center mb-6 border border-slate-200"
        >
          <Text className="text-sky-600 font-semibold">+ Add Set</Text>
        </Pressable>

        <Pressable
          onPress={handleSave}
          disabled={isSaving}
          className={`rounded-2xl py-4 items-center mb-8 ${isSaving ? "bg-sky-300" : "bg-sky-500"}`}
        >
          <Text className="text-white font-bold text-lg">
            {isSaving ? "Saving..." : "Start Swim"}
          </Text>
        </Pressable>
      </View>
    </ScrollView>
  );
}