// src/components/MilestoneTimeline.js
import React, { useEffect, useState, useCallback } from 'react';

const today = new Date();

const MilestoneTimeline = ({ careerPathId, authFetch, activeView, setActiveView }) => {

  const [milestones, setMilestones] = useState({ Career: [], Financial: [], Retirement: [] });
  const [newMilestone, setNewMilestone] = useState({ title: '', date: '', description: '', progress: 0 });
  const [showForm, setShowForm] = useState(false);
  const [editingMilestone, setEditingMilestone] = useState(null);

  const fetchMilestones = useCallback(async () => {
    if (!careerPathId) {
      console.warn('No careerPathId provided.');
      return;
    }

    const res = await authFetch(`/api/premium/milestones?careerPathId=${careerPathId}`);
    if (!res) {
      console.error('Failed to fetch milestones.');
      return;
    }

    const data = await res.json();

    const raw = Array.isArray(data.milestones[0])
    ? data.milestones.flat()
    : data.milestones.milestones || data.milestones;

const flatMilestones = Array.isArray(data.milestones[0])
? data.milestones.flat()
: data.milestones;

const filteredMilestones = raw.filter(
  (m) => m.career_path_id === careerPathId
);  

    const categorized = { Career: [], Financial: [], Retirement: [] };

    filteredMilestones.forEach((m) => {
  const type = m.milestone_type;
  if (categorized[type]) {
    categorized[type].push(m);
  } else {
    console.warn(`Unknown milestone type: ${type}`);
  }
});
    

    setMilestones(categorized);
    console.log('Milestones set for view:', categorized);

  }, [careerPathId, authFetch]);

  // ✅ useEffect simply calls the function
  useEffect(() => {
    fetchMilestones();
  }, [fetchMilestones]);

  const saveMilestone = async () => {
    const url = editingMilestone
      ? `/api/premium/milestones/${editingMilestone.id}`
      : `/api/premium/milestone`;
    const method = editingMilestone ? 'PUT' : 'POST';
    const payload = {
      milestone_type: activeView,
      title: newMilestone.title,
      description: newMilestone.description,
      date: newMilestone.date,
      career_path_id: careerPathId,
      progress: newMilestone.progress,
      status: newMilestone.progress === 100 ? 'completed' : 'planned',
    };

    try {
      console.log('Sending request to:', url);
      console.log('HTTP Method:', method);
      console.log('Payload:', payload);

      const res = await authFetch(url, {
        method,
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(payload),
      });

      if (!res.ok) {
        const errorData = await res.json();
        console.error('Failed to save milestone:', errorData);
      
        let message = 'An error occurred while saving the milestone.';
        if (errorData?.error === 'Missing required fields') {
          message = 'Please complete all required fields before saving.';
          console.warn('Missing fields:', errorData.details);
        }
      
        alert(message); // Replace with your preferred UI messaging
        return;
      }
      
      const savedMilestone = await res.json();

      // Update state locally instead of fetching all milestones
      setMilestones((prevMilestones) => {
        const updatedMilestones = { ...prevMilestones };
        if (editingMilestone) {
          // Update the existing milestone
          updatedMilestones[activeView] = updatedMilestones[activeView].map((m) =>
            m.id === editingMilestone.id ? savedMilestone : m
          );
        } else {
          // Add the new milestone
          updatedMilestones[activeView].push(savedMilestone);
        }
        return updatedMilestones;
      });

      setShowForm(false);
      setEditingMilestone(null);
      setNewMilestone({ title: '', description: '', date: '', progress: 0 });
    } catch (error) {
      console.error('Error saving milestone:', error);
    }
  };

  // Calculate last milestone date properly by combining all arrays
  const allMilestones = [...milestones.Career, ...milestones.Financial, ...milestones.Retirement];
  const lastDate = allMilestones.reduce(
    (latest, m) => (new Date(m.date) > latest ? new Date(m.date) : latest),
    today
  );

  const calcPosition = (date) => {
    const start = today.getTime();
    const end = lastDate.getTime();
    const position = ((new Date(date).getTime() - start) / (end - start)) * 100;
    return Math.min(Math.max(position, 0), 100);
  };

  console.log('Rendering view:', activeView, milestones?.[activeView]);

  if (!activeView || !milestones?.[activeView]) {
    return (
      <div className="milestone-timeline">
        <p>Loading milestones...</p>
      </div>
    );
  }

  return (
    <div className="milestone-timeline">
      <div className="view-selector">
        {['Career', 'Financial', 'Retirement'].map((view) => (
  <button
    key={view}
    className={activeView === view ? 'active' : ''}
    onClick={() => setActiveView(view)}
  >
    {view}
  </button>
))}
      </div>

      <button onClick={() => {
        if (showForm) {
          setShowForm(false);
          setEditingMilestone(null);
          setNewMilestone({ title: '', date: '', progress: 0 });
        } else {
          setShowForm(true);
        }
      }}>
        {showForm ? 'Cancel' : '+ New Milestone'}
      </button>

      {showForm && (
        <div className="form">
          <input type="text" placeholder="Title" value={newMilestone.title} onChange={(e) => setNewMilestone({ ...newMilestone, title: e.target.value })} />
          <input type="text" placeholder="Description" value={newMilestone.description} onChange={(e) => setNewMilestone({ ...newMilestone, description: e.target.value })} />
          <input type="date" value={newMilestone.date} onChange={(e) => setNewMilestone({ ...newMilestone, date: e.target.value })} />
          <input type="number" placeholder="Progress (%)" value={newMilestone.progress} onChange={(e) => setNewMilestone({ ...newMilestone, progress: parseInt(e.target.value, 10) })} />
          <button onClick={saveMilestone}>{editingMilestone ? 'Update' : 'Add'} Milestone</button>
        </div>
      )}

      <div className="milestone-timeline-container">
        <div className="milestone-timeline-line" />
        {milestones[activeView]?.map((m) => (
          <div key={m.id} className="milestone-timeline-post" style={{ left: `${calcPosition(m.date)}%` }} onClick={() => {
            setEditingMilestone(m);
            setNewMilestone({ title: m.title, date: m.date, progress: m.progress });
            setShowForm(true);
          }}>
            <div className="milestone-timeline-dot" />
            <div className="milestone-content">
              <div className="title">{m.title}</div>
              <div className="progress-bar">
                <div className="progress" style={{ width: `${m.progress}%` }} />
              </div>
              <div className="date">{m.date}</div>
            </div>
          </div>
        ))}
      </div>
    </div>
  );
};

export default MilestoneTimeline;