// src/components/MilestoneAddModal.js
import React, { useState, useEffect } from 'react';
import authFetch from '../utils/authFetch.js';

const MilestoneAddModal = ({
  show,
  onClose,
  defaultScenarioId,
  scenarioId,          // which scenario this milestone applies to
  editMilestone,       // if editing an existing milestone, pass its data
  apiURL
}) => {
  // Basic milestone fields
  const [title, setTitle] = useState('');
  const [description, setDescription] = useState('');

  // We'll store an array of impacts. Each impact is { impact_type, direction, amount, start_month, end_month }
  const [impacts, setImpacts] = useState([]);

  // On open, if editing, fill in existing fields
  useEffect(() => {
    if (!show) return; // if modal is hidden, do nothing

    if (editMilestone) {
      setTitle(editMilestone.title || '');
      setDescription(editMilestone.description || '');
      // If editing, you might fetch existing impacts from the server or they could be passed in
      if (editMilestone.impacts) {
        setImpacts(editMilestone.impacts);
      } else {
        // fetch from backend if needed
        // e.g. GET /api/premium/milestones/:id/impacts
      }
    } else {
      // Creating a new milestone
      setTitle('');
      setDescription('');
      setImpacts([]);
    }
  }, [show, editMilestone]);

  // Handler: add a new blank impact
  const handleAddImpact = () => {
    setImpacts((prev) => [
      ...prev,
      {
        impact_type: 'ONE_TIME',
        direction: 'subtract',
        amount: 0,
        start_month: 0,
        end_month: null
      }
    ]);
  };

  // Handler: update a single impact in the array
  const handleImpactChange = (index, field, value) => {
    setImpacts((prev) => {
      const updated = [...prev];
      updated[index] = { ...updated[index], [field]: value };
      return updated;
    });
  };

  // Handler: remove an impact row
  const handleRemoveImpact = (index) => {
    setImpacts((prev) => prev.filter((_, i) => i !== index));
  };

  // Handler: Save everything to the server
  const handleSave = async () => {
    try {
      let milestoneId;
      if (editMilestone) {
        // 1) Update existing milestone
        milestoneId = editMilestone.id;
        await authFetch(`${apiURL}/premium/milestones/${milestoneId}`, {
          method: 'PUT',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({
            title,
            description,
            scenario_id: scenarioId,
            // Possibly other fields
          })
        });
        // Then handle impacts below...
      } else {
        // 1) Create new milestone
        const res = await authFetch(`${apiURL}/premium/milestones`, {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({
            title,
            description,
            scenario_id: scenarioId
          })
        });
        if (!res.ok) throw new Error('Failed to create milestone');
        const created = await res.json();
        milestoneId = created.id;  // assuming the response returns { id: newMilestoneId }
      }

      // 2) For the impacts, we can do a batch approach or individual calls
      //    For simplicity, let's do multiple POST calls
      for (const impact of impacts) {
        // If editing, you might do a PUT if the impact already has an id
        await authFetch(`${apiURL}/premium/milestone-impacts`, {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({
            milestone_id: milestoneId,
            impact_type: impact.impact_type,
            direction: impact.direction,
            amount: parseFloat(impact.amount) || 0,
            start_month: parseInt(impact.start_month, 10) || 0,
            end_month: impact.end_month !== null
              ? parseInt(impact.end_month, 10)
              : null,
            created_at: new Date().toISOString(),
            updated_at: new Date().toISOString()
          })
        });
      }

      // Done, close modal
      onClose();
    } catch (err) {
      console.error('Failed to save milestone + impacts:', err);
      // Show some UI error if needed
    }
  };

  if (!show) return null;

  return (
    <div className="modal-backdrop">
      <div className="modal-container">
        <h2 className="text-xl font-bold mb-2">
          {editMilestone ? 'Edit Milestone' : 'Add Milestone'}
        </h2>

        <div className="mb-3">
          <label className="block font-semibold">Title</label>
          <input
            value={title}
            onChange={(e) => setTitle(e.target.value)}
            className="border w-full px-2 py-1"
          />
        </div>

        <div className="mb-3">
          <label className="block font-semibold">Description</label>
          <textarea
            value={description}
            onChange={(e) => setDescription(e.target.value)}
            className="border w-full px-2 py-1"
          />
        </div>

        {/* Impacts Section */}
        <h3 className="text-lg font-semibold mt-4">Financial Impacts</h3>
        {impacts.map((impact, i) => (
          <div key={i} className="border rounded p-2 my-2">
            <div className="flex items-center justify-between">
              <p>Impact #{i + 1}</p>
              <button
                className="text-red-500"
                onClick={() => handleRemoveImpact(i)}
              >
                Remove
              </button>
            </div>

            {/* Impact Type */}
            <div className="mt-2">
              <label className="block font-semibold">Type</label>
              <select
                value={impact.impact_type}
                onChange={(e) =>
                  handleImpactChange(i, 'impact_type', e.target.value)
                }
              >
                <option value="ONE_TIME">One-Time</option>
                <option value="MONTHLY">Monthly</option>
              </select>
            </div>

            {/* Direction */}
            <div className="mt-2">
              <label className="block font-semibold">Direction</label>
              <select
                value={impact.direction}
                onChange={(e) =>
                  handleImpactChange(i, 'direction', e.target.value)
                }
              >
                <option value="add">Add (Income)</option>
                <option value="subtract">Subtract (Expense)</option>
              </select>
            </div>

            {/* Amount */}
            <div className="mt-2">
              <label className="block font-semibold">Amount</label>
              <input
                type="number"
                value={impact.amount}
                onChange={(e) =>
                  handleImpactChange(i, 'amount', e.target.value)
                }
                className="border px-2 py-1 w-full"
              />
            </div>

            {/* Start Month */}
            <div className="mt-2">
              <label className="block font-semibold">Start Month</label>
              <input
                type="number"
                value={impact.start_month}
                onChange={(e) =>
                  handleImpactChange(i, 'start_month', e.target.value)
                }
                className="border px-2 py-1 w-full"
              />
            </div>

            {/* End Month (for MONTHLY, can be null/blank if indefinite) */}
            {impact.impact_type === 'MONTHLY' && (
              <div className="mt-2">
                <label className="block font-semibold">End Month (optional)</label>
                <input
                  type="number"
                  value={impact.end_month || ''}
                  onChange={(e) =>
                    handleImpactChange(i, 'end_month', e.target.value || null)
                  }
                  className="border px-2 py-1 w-full"
                  placeholder="Leave blank for indefinite"
                />
              </div>
            )}
          </div>
        ))}

        <button onClick={handleAddImpact} className="bg-gray-200 px-3 py-1 my-2">
          + Add Impact
        </button>

        {/* Modal Actions */}
        <div className="flex justify-end mt-4">
          <button className="mr-2" onClick={onClose}>
            Cancel
          </button>
          <button className="bg-blue-500 text-white px-4 py-2 rounded" onClick={handleSave}>
            Save Milestone
          </button>
        </div>
      </div>
    </div>
  );
};

export default MilestoneAddModal;