import React, { useEffect, useMemo, useState } from 'react';
import {
  ProfileQuestion,
  ProfileQuestionInputType,
  ProfileQuestionOption,
  ProfileQuestionUpsertData,
  userService
} from '../services/membershipService';

interface AdminProfileQuestionManagerProps {
  onQuestionsChanged?: () => void;
}

const INPUT_TYPES: ProfileQuestionInputType[] = ['text', 'number', 'boolean', 'date', 'select'];

const optionsToText = (options: ProfileQuestionOption[] | null | undefined): string => {
  if (!options || options.length === 0) {
    return '';
  }
  return options.map((option) => `${option.label}|${option.value}`).join('\n');
};

const textToOptions = (value: string): ProfileQuestionOption[] => {
  return value
    .split('\n')
    .map((line) => line.trim())
    .filter(Boolean)
    .map((line) => {
      const [labelPart, valuePart] = line.split('|');
      const label = (labelPart || '').trim();
      const optionValue = (valuePart || labelPart || '').trim();
      return { label, value: optionValue };
    })
    .filter((option) => option.label.length > 0 && option.value.length > 0);
};

const AdminProfileQuestionManager: React.FC<AdminProfileQuestionManagerProps> = ({ onQuestionsChanged }) => {
  const [questions, setQuestions] = useState<ProfileQuestion[]>([]);
  const [loading, setLoading] = useState(true);
  const [saving, setSaving] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [editingQuestionId, setEditingQuestionId] = useState<number | null>(null);
  const [listSearch, setListSearch] = useState('');

  const emptyForm: ProfileQuestionUpsertData = {
    key: '',
    label: '',
    help_text: '',
    input_type: 'text',
    placeholder: '',
    options: null,
    is_required: false,
    is_active: true,
    admin_only_edit: false,
    display_order: 0,
    depends_on_question_id: null,
    depends_on_value: null
  };

  const [formData, setFormData] = useState<ProfileQuestionUpsertData>(emptyForm);
  const [optionsText, setOptionsText] = useState('');

  const loadQuestions = async () => {
    try {
      setLoading(true);
      const data = await userService.getAdminProfileQuestions(true);
      setQuestions(data);
      setError(null);
    } catch (err: any) {
      setError(err.response?.data?.detail || err.message || 'Failed to load questions');
    } finally {
      setLoading(false);
    }
  };

  useEffect(() => {
    loadQuestions();
  }, []);

  const dependencyCandidates = useMemo(() => {
    return questions.filter((question) => question.id !== editingQuestionId);
  }, [questions, editingQuestionId]);

  const selectedDependencyQuestion = useMemo(() => {
    if (!formData.depends_on_question_id) {
      return null;
    }
    return questions.find((question) => question.id === formData.depends_on_question_id) || null;
  }, [questions, formData.depends_on_question_id]);

  const filteredQuestions = useMemo(() => {
    const term = listSearch.trim().toLowerCase();
    if (!term) {
      return questions;
    }
    return questions.filter((question) =>
      question.label.toLowerCase().includes(term) ||
      question.key.toLowerCase().includes(term)
    );
  }, [questions, listSearch]);

  const resetForm = () => {
    setFormData(emptyForm);
    setOptionsText('');
    setEditingQuestionId(null);
  };

  const handleEdit = (question: ProfileQuestion) => {
    setEditingQuestionId(question.id);
    setFormData({
      key: question.key,
      label: question.label,
      help_text: question.help_text,
      input_type: question.input_type,
      placeholder: question.placeholder,
      options: question.options,
      is_required: question.is_required,
      is_active: question.is_active,
      admin_only_edit: question.admin_only_edit,
      display_order: question.display_order,
      depends_on_question_id: question.depends_on_question_id,
      depends_on_value: question.depends_on_value
    });
    setOptionsText(optionsToText(question.options));
  };

  const handleSave = async () => {
    setSaving(true);
    setError(null);

    try {
      const payload: ProfileQuestionUpsertData = {
        ...formData,
        key: formData.key.trim(),
        label: formData.label.trim(),
        help_text: formData.help_text?.trim() || null,
        placeholder: formData.placeholder?.trim() || null,
        depends_on_value: formData.depends_on_value?.trim() || null,
        options: formData.input_type === 'select' ? textToOptions(optionsText) : null,
      };

      if (editingQuestionId) {
        await userService.updateAdminProfileQuestion(editingQuestionId, payload);
      } else {
        await userService.createAdminProfileQuestion(payload);
      }

      await loadQuestions();
      resetForm();
      onQuestionsChanged?.();
    } catch (err: any) {
      setError(err.response?.data?.detail || err.message || 'Failed to save question');
    } finally {
      setSaving(false);
    }
  };

  const handleDeactivate = async (questionId: number) => {
    if (!window.confirm('Deactivate this question? Existing answers are kept.')) {
      return;
    }

    try {
      await userService.deactivateAdminProfileQuestion(questionId);
      await loadQuestions();
      onQuestionsChanged?.();
    } catch (err: any) {
      setError(err.response?.data?.detail || err.message || 'Failed to deactivate question');
    }
  };

  return (
    <div className="card" style={{ marginTop: '20px' }}>
      <h3 style={{ marginBottom: '10px' }}>Profile Questions (Admin)</h3>
      <p style={{ marginBottom: '16px', color: '#555' }}>
        Manage the set of profile questions users can answer. You can add follow-up questions with dependencies.
      </p>

      {error && <div className="alert alert-error">{error}</div>}

      <div style={{ display: 'grid', gap: '10px', marginBottom: '20px' }}>
        <input
          type="text"
          placeholder="Question key (e.g. pilot_license_type)"
          value={formData.key}
          onChange={(event) => setFormData((prev) => ({ ...prev, key: event.target.value }))}
          style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
        />
        <input
          type="text"
          placeholder="Question label"
          value={formData.label}
          onChange={(event) => setFormData((prev) => ({ ...prev, label: event.target.value }))}
          style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
        />
        <textarea
          placeholder="Help text (optional)"
          value={formData.help_text || ''}
          onChange={(event) => setFormData((prev) => ({ ...prev, help_text: event.target.value }))}
          rows={2}
          style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
        />

        <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fit, minmax(180px, 1fr))', gap: '10px' }}>
          <select
            value={formData.input_type}
            onChange={(event) => setFormData((prev) => ({ ...prev, input_type: event.target.value as ProfileQuestionInputType }))}
            style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
          >
            {INPUT_TYPES.map((type) => (
              <option key={type} value={type}>{type}</option>
            ))}
          </select>

          <input
            type="number"
            placeholder="Display order"
            value={formData.display_order ?? 0}
            onChange={(event) => setFormData((prev) => ({ ...prev, display_order: Number(event.target.value) }))}
            style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
          />

          <input
            type="text"
            placeholder="Placeholder"
            value={formData.placeholder || ''}
            onChange={(event) => setFormData((prev) => ({ ...prev, placeholder: event.target.value }))}
            style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
          />
        </div>

        <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fit, minmax(180px, 1fr))', gap: '10px' }}>
          <select
            value={formData.depends_on_question_id ?? ''}
            onChange={(event) => {
              const nextValue = event.target.value;
              setFormData((prev) => ({
                ...prev,
                depends_on_question_id: nextValue ? Number(nextValue) : null,
                depends_on_value: null
              }));
            }}
            style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
          >
            <option value="">No dependency</option>
            {dependencyCandidates.map((question) => (
              <option key={question.id} value={question.id}>{question.label}</option>
            ))}
          </select>

          {!selectedDependencyQuestion && (
            <input
              type="text"
              placeholder="Choose a dependency question first"
              value=""
              disabled
              style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px', background: '#f5f7fa' }}
            />
          )}

          {selectedDependencyQuestion?.input_type === 'select' && (
            <select
              value={formData.depends_on_value || ''}
              onChange={(event) => setFormData((prev) => ({ ...prev, depends_on_value: event.target.value || null }))}
              style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
            >
              <option value="">Any answered value</option>
              {selectedDependencyQuestion.options.map((option) => (
                <option key={option.value} value={option.value}>{option.label}</option>
              ))}
            </select>
          )}

          {selectedDependencyQuestion?.input_type === 'boolean' && (
            <select
              value={formData.depends_on_value || ''}
              onChange={(event) => setFormData((prev) => ({ ...prev, depends_on_value: event.target.value || null }))}
              style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
            >
              <option value="">Any answered value</option>
              <option value="true">Yes</option>
              <option value="false">No</option>
            </select>
          )}

          {selectedDependencyQuestion && !['select', 'boolean'].includes(selectedDependencyQuestion.input_type) && (
            <input
              type={selectedDependencyQuestion.input_type === 'number' ? 'number' : selectedDependencyQuestion.input_type === 'date' ? 'date' : 'text'}
              placeholder="Show when parent answer equals..."
              value={formData.depends_on_value || ''}
              onChange={(event) => setFormData((prev) => ({ ...prev, depends_on_value: event.target.value || null }))}
              style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
            />
          )}
        </div>

        {formData.input_type === 'select' && (
          <textarea
            value={optionsText}
            onChange={(event) => setOptionsText(event.target.value)}
            rows={4}
            placeholder={'Options (one per line):\nNo|none\nPrivate Pilot|ppl'}
            style={{ padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
          />
        )}

        <div style={{ display: 'flex', gap: '16px', flexWrap: 'wrap' }}>
          <label>
            <input
              type="checkbox"
              checked={Boolean(formData.is_required)}
              onChange={(event) => setFormData((prev) => ({ ...prev, is_required: event.target.checked }))}
              style={{ marginRight: '6px' }}
            />
            Required
          </label>
          <label>
            <input
              type="checkbox"
              checked={Boolean(formData.admin_only_edit)}
              onChange={(event) => setFormData((prev) => ({ ...prev, admin_only_edit: event.target.checked }))}
              style={{ marginRight: '6px' }}
            />
            Admin-only edits
          </label>
          <label>
            <input
              type="checkbox"
              checked={Boolean(formData.is_active)}
              onChange={(event) => setFormData((prev) => ({ ...prev, is_active: event.target.checked }))}
              style={{ marginRight: '6px' }}
            />
            Active
          </label>
        </div>

        <div style={{ display: 'flex', gap: '10px' }}>
          <button className="btn btn-primary" onClick={handleSave} disabled={saving || !formData.key || !formData.label}>
            {saving ? 'Saving...' : editingQuestionId ? 'Update Question' : 'Create Question'}
          </button>
          {editingQuestionId && (
            <button className="btn btn-secondary" onClick={resetForm}>
              Cancel Edit
            </button>
          )}
        </div>
      </div>

      <h4 style={{ marginBottom: '10px' }}>Existing Questions</h4>
      <input
        type="text"
        placeholder="Search by label or key..."
        value={listSearch}
        onChange={(event) => setListSearch(event.target.value)}
        style={{ marginBottom: '10px', width: '100%', padding: '8px', border: '1px solid #ddd', borderRadius: '4px' }}
      />
      {loading ? (
        <p>Loading questions...</p>
      ) : (
        <div className="table-container">
          <table style={{ width: '100%', borderCollapse: 'collapse' }}>
            <thead>
              <tr style={{ borderBottom: '2px solid #ddd' }}>
                <th style={{ padding: '8px', textAlign: 'left' }}>Order</th>
                <th style={{ padding: '8px', textAlign: 'left' }}>Label</th>
                <th style={{ padding: '8px', textAlign: 'left' }}>Type</th>
                <th style={{ padding: '8px', textAlign: 'left' }}>Key</th>
                <th style={{ padding: '8px', textAlign: 'left' }}>Status</th>
                <th style={{ padding: '8px', textAlign: 'left' }}>Actions</th>
              </tr>
            </thead>
            <tbody>
              {filteredQuestions.map((question) => (
                <tr key={question.id} style={{ borderBottom: '1px solid #eee' }}>
                  <td style={{ padding: '8px' }}>{question.display_order}</td>
                  <td style={{ padding: '8px' }}>
                    {question.label}
                    {question.admin_only_edit && (
                      <span style={{ backgroundColor: '#eef2ff', color: '#3730a3', marginLeft: '8px', padding: '2px 7px', borderRadius: '999px', fontWeight: 600, fontSize: '12px' }}>
                        Admin Managed
                      </span>
                    )}
                  </td>
                  <td style={{ padding: '8px' }}>{question.input_type}</td>
                  <td style={{ padding: '8px' }}>{question.key}</td>
                  <td style={{ padding: '8px' }}>{question.is_active ? 'Active' : 'Inactive'}</td>
                  <td style={{ padding: '8px' }}>
                    <button className="btn btn-secondary" style={{ fontSize: '12px', padding: '4px 8px', marginRight: '6px' }} onClick={() => handleEdit(question)}>
                      Edit
                    </button>
                    {question.is_active && (
                      <button className="btn btn-danger" style={{ fontSize: '12px', padding: '4px 8px' }} onClick={() => handleDeactivate(question.id)}>
                        Deactivate
                      </button>
                    )}
                  </td>
                </tr>
              ))}
            </tbody>
          </table>
          {filteredQuestions.length === 0 && (
            <p style={{ padding: '10px', color: '#666' }}>No questions match your search.</p>
          )}
        </div>
      )}
    </div>
  );
};

export default AdminProfileQuestionManager;