import { WorkoutSession, ExerciseDef, ExerciseType, WorkoutSet, WorkoutPlan } from '../types';
import { updateUserProfile } from './auth';

// Helper to namespace keys
const getKey = (base: string, userId: string) => `${base}_${userId}`;

const SESSIONS_KEY = 'gymflow_sessions';
const EXERCISES_KEY = 'gymflow_exercises'; // Custom exercises are per user
const PLANS_KEY = 'gymflow_plans';

const DEFAULT_EXERCISES: ExerciseDef[] = [
  { id: 'bp', name: 'Жим лежа', type: ExerciseType.STRENGTH },
  { id: 'sq', name: 'Приседания со штангой', type: ExerciseType.STRENGTH },
  { id: 'dl', name: 'Становая тяга', type: ExerciseType.STRENGTH },
  { id: 'pu', name: 'Подтягивания', type: ExerciseType.BODYWEIGHT, bodyWeightPercentage: 100 },
  { id: 'run', name: 'Бег', type: ExerciseType.CARDIO },
  { id: 'plank', name: 'Планка', type: ExerciseType.STATIC, bodyWeightPercentage: 100 }, 
  { id: 'dip', name: 'Отжимания на брусьях', type: ExerciseType.BODYWEIGHT, bodyWeightPercentage: 100 },
  { id: 'pushup', name: 'Отжимания от пола', type: ExerciseType.BODYWEIGHT, bodyWeightPercentage: 65 },
  { id: 'air_sq', name: 'Приседания (свой вес)', type: ExerciseType.BODYWEIGHT, bodyWeightPercentage: 75 },
];

export const getSessions = (userId: string): WorkoutSession[] => {
  try {
    const data = localStorage.getItem(getKey(SESSIONS_KEY, userId));
    return data ? JSON.parse(data) : [];
  } catch (e) {
    return [];
  }
};

export const saveSession = (userId: string, session: WorkoutSession): void => {
  const sessions = getSessions(userId);
  const index = sessions.findIndex(s => s.id === session.id);
  if (index >= 0) {
    sessions[index] = session;
  } else {
    sessions.unshift(session);
  }
  localStorage.setItem(getKey(SESSIONS_KEY, userId), JSON.stringify(sessions));

  // Auto-update user weight profile if present in session
  if (session.userBodyWeight) {
      updateUserProfile(userId, { weight: session.userBodyWeight });
  }
};

export const deleteSession = (userId: string, id: string): void => {
  let sessions = getSessions(userId);
  sessions = sessions.filter(s => s.id !== id);
  localStorage.setItem(getKey(SESSIONS_KEY, userId), JSON.stringify(sessions));
};

export const deleteAllUserData = (userId: string) => {
    localStorage.removeItem(getKey(SESSIONS_KEY, userId));
    localStorage.removeItem(getKey(EXERCISES_KEY, userId));
    localStorage.removeItem(getKey(PLANS_KEY, userId));
};

export const getExercises = (userId: string): ExerciseDef[] => {
  try {
    const data = localStorage.getItem(getKey(EXERCISES_KEY, userId));
    const savedExercises: ExerciseDef[] = data ? JSON.parse(data) : [];
    
    // Create a map of saved exercises for easy lookup
    const savedMap = new Map(savedExercises.map(ex => [ex.id, ex]));

    // Start with defaults
    const mergedExercises = DEFAULT_EXERCISES.map(defEx => {
      // If user has a saved version of this default exercise (e.g. edited or archived), use that
      if (savedMap.has(defEx.id)) {
        const saved = savedMap.get(defEx.id)!;
        savedMap.delete(defEx.id); // Remove from map so we don't add it again
        return saved;
      }
      return defEx;
    });

    // Add remaining custom exercises (those that are not overrides of defaults)
    return [...mergedExercises, ...Array.from(savedMap.values())];
  } catch (e) {
    return DEFAULT_EXERCISES;
  }
};

export const saveExercise = (userId: string, exercise: ExerciseDef): void => {
  try {
    const data = localStorage.getItem(getKey(EXERCISES_KEY, userId));
    let list: ExerciseDef[] = data ? JSON.parse(data) : [];
    
    const index = list.findIndex(e => e.id === exercise.id);
    if (index >= 0) {
      list[index] = exercise;
    } else {
      list.push(exercise);
    }
    localStorage.setItem(getKey(EXERCISES_KEY, userId), JSON.stringify(list));
  } catch {}
};

export const getLastSetForExercise = (userId: string, exerciseId: string): WorkoutSet | undefined => {
    const sessions = getSessions(userId);
    for (const session of sessions) {
        for (let i = session.sets.length - 1; i >= 0; i--) {
            if (session.sets[i].exerciseId === exerciseId) {
                return session.sets[i];
            }
        }
    }
    return undefined;
}

export const getPlans = (userId: string): WorkoutPlan[] => {
  try {
    const data = localStorage.getItem(getKey(PLANS_KEY, userId));
    return data ? JSON.parse(data) : [];
  } catch {
    return [];
  }
};

export const savePlan = (userId: string, plan: WorkoutPlan): void => {
  const plans = getPlans(userId);
  const index = plans.findIndex(p => p.id === plan.id);
  if (index >= 0) {
    plans[index] = plan;
  } else {
    plans.push(plan);
  }
  localStorage.setItem(getKey(PLANS_KEY, userId), JSON.stringify(plans));
};

export const deletePlan = (userId: string, id: string): void => {
  const plans = getPlans(userId).filter(p => p.id !== id);
  localStorage.setItem(getKey(PLANS_KEY, userId), JSON.stringify(plans));
};