import { useEffect, useState } from 'react';
import { Pencil, Save, X, UserPlus, Trash2 } from 'lucide-react';
import { useUi } from '../../context/ui-context.jsx';
import { useAsync, useAction } from '../../hooks/useAsync.js';
import { updateProject, addProjectMember, removeProjectMember } from '../../services/projects.js';
import { listCatalog } from '../../services/catalogs.js';
import { listDepartments } from '../../services/departments.js';
import { listUsers } from '../../services/users.js';
import { Button } from '../../components/Button.jsx';
import { Field, FieldRow } from '../../components/Field.jsx';
import { ComboBox } from '../../components/ComboBox.jsx';
import { StatusBadge, ProgressBar } from '../../components/StatusBadge.jsx';
import { Badge } from '../../components/Badge.jsx';

function flatten(nodes, acc = []) {
  for (const n of nodes) { acc.push(n); if (n.children?.length) flatten(n.children, acc); }
  return acc;
}

const RISK_COLOR = { low: 'success', medium: 'warning', high: 'danger' };

function toForm(p) {
  return {
    name: p.name, description: p.description || '', objective: p.objective || '',
    projectTypeId: p.project_type_id || '', priorityId: p.priority_id, statusId: p.status_id,
    ownerUserId: p.owner_user_id,
    requestingDepartmentId: p.requesting_department_id || '', responsibleDepartmentId: p.responsible_department_id || '',
    startDate: p.start_date || '', estimatedEndDate: p.estimated_end_date || '', actualEndDate: p.actual_end_date || '',
    riskLevel: p.risk_level, notes: p.notes || '',
  };
}

export default function ProjectInfoTab({ project, onChanged }) {
  const { t, pushToast, openDialog } = useUi();
  const runAction = useAction();
  const { data: priorities } = useAsync(() => listCatalog('priorities'), []);
  const { data: statuses } = useAsync(() => listCatalog('project-statuses'), []);
  const { data: types } = useAsync(() => listCatalog('project-types'), []);
  const { data: deptTree } = useAsync(listDepartments, []);
  const { data: users } = useAsync(listUsers, []);

  const [editing, setEditing] = useState(false);
  const [form, setForm] = useState(() => toForm(project));
  const [addingMember, setAddingMember] = useState('');

  useEffect(() => { setForm(toForm(project)); }, [project]);

  const deptOptions = deptTree ? flatten(deptTree).map((d) => ({ value: d.id, label: d.name })) : [];
  const priorityOptions = (priorities || []).map((p) => ({ value: p.id, label: p.name }));
  const statusOptions = (statuses || []).map((s) => ({ value: s.id, label: s.name }));
  const typeOptions = (types || []).map((tp) => ({ value: tp.id, label: tp.name }));
  const userOptions = (users || []).filter((u) => !project.members.some((m) => m.user_id === u.id)).map((u) => ({ value: u.id, label: u.name }));

  async function save() {
    const changed = JSON.stringify(form) !== JSON.stringify(toForm(project));
    if (!changed) { setEditing(false); return; }
    await runAction(async () => {
      await updateProject(project.id, {
        ...form,
        projectTypeId: form.projectTypeId || null,
        requestingDepartmentId: form.requestingDepartmentId || null,
        responsibleDepartmentId: form.responsibleDepartmentId || null,
        startDate: form.startDate || null,
        estimatedEndDate: form.estimatedEndDate || null,
        actualEndDate: form.actualEndDate || null,
      });
      setEditing(false);
      pushToast({ tone: 'success', message: t('common_saved') });
      onChanged();
    });
  }

  async function addMember() {
    if (!addingMember) return;
    await runAction(async () => {
      await addProjectMember(project.id, Number(addingMember));
      setAddingMember('');
      onChanged();
    });
  }

  function confirmRemoveMember(member) {
    openDialog({
      tone: 'warning',
      title: t('common_confirm_delete_title'),
      message: t('common_confirm_delete_msg'),
      actions: [
        { label: t('common_cancel'), variant: 'standard' },
        { label: t('common_delete'), variant: 'danger', onClick: () => runAction(async () => { await removeProjectMember(project.id, member.user_id); onChanged(); }) },
      ],
    });
  }

  return (
    <div>
      <div style={{ display: 'flex', justifyContent: 'flex-end', marginBottom: 12 }}>
        {editing ? (
          <div style={{ display: 'flex', gap: 8 }}>
            <Button variant="accent" icon={Save} onClick={save}>{t('common_save')}</Button>
            <Button variant="standard" icon={X} onClick={() => { setForm(toForm(project)); setEditing(false); }}>{t('common_cancel')}</Button>
          </div>
        ) : (
          <Button variant="standard" icon={Pencil} onClick={() => setEditing(true)}>{t('common_edit')}</Button>
        )}
      </div>

      {!editing ? (
        <div className="panel-card">
          <FieldRow>
            <Field label={t('common_status')}><StatusBadge name={project.status_name} color={project.status_color} /></Field>
            <Field label={t('common_priority')}><StatusBadge name={project.priority_name} color={project.priority_color} /></Field>
            <Field label={t('project_risk')}><Badge color={RISK_COLOR[project.risk_level]}>{t(`risk_${project.risk_level}`)}</Badge></Field>
          </FieldRow>
          <Field label={t('common_description')}><div>{project.description || '—'}</div></Field>
          <Field label={t('project_objective')}><div>{project.objective || '—'}</div></Field>
          <FieldRow>
            <Field label={t('project_type')}><div>{project.project_type_name || '—'}</div></Field>
            <Field label={t('project_owner')}><div>{project.owner_name}</div></Field>
          </FieldRow>
          <FieldRow>
            <Field label={t('project_requesting_department')}><div>{project.requesting_department_name || '—'}</div></Field>
            <Field label={t('project_responsible_department')}><div>{project.responsible_department_name || '—'}</div></Field>
          </FieldRow>
          <FieldRow>
            <Field label={t('project_start_date')}><div>{project.start_date || '—'}</div></Field>
            <Field label={t('project_estimated_end_date')}><div>{project.estimated_end_date || '—'}</div></Field>
            <Field label={t('project_actual_end_date')}><div>{project.actual_end_date || '—'}</div></Field>
          </FieldRow>
          <Field label={t('project_progress')}><ProgressBar value={Number(project.progress_pct)} /></Field>
          <Field label={t('project_notes')}><div>{project.notes || '—'}</div></Field>
        </div>
      ) : (
        <div className="panel-card">
          <Field label={t('common_name')}>
            <input className="input" value={form.name} onChange={(e) => setForm((f) => ({ ...f, name: e.target.value }))} />
          </Field>
          <Field label={t('common_description')}>
            <textarea className="textarea" value={form.description} onChange={(e) => setForm((f) => ({ ...f, description: e.target.value }))} />
          </Field>
          <Field label={t('project_objective')}>
            <textarea className="textarea" value={form.objective} onChange={(e) => setForm((f) => ({ ...f, objective: e.target.value }))} />
          </Field>
          <FieldRow>
            <Field label={t('project_type')}>
              <ComboBox options={[{ value: '', label: '—' }, ...typeOptions]} value={form.projectTypeId} onChange={(v) => setForm((f) => ({ ...f, projectTypeId: v }))} />
            </Field>
            <Field label={t('common_priority')}>
              <ComboBox options={priorityOptions} value={form.priorityId} onChange={(v) => setForm((f) => ({ ...f, priorityId: v }))} />
            </Field>
            <Field label={t('common_status')}>
              <ComboBox options={statusOptions} value={form.statusId} onChange={(v) => setForm((f) => ({ ...f, statusId: v }))} />
            </Field>
          </FieldRow>
          <FieldRow>
            <Field label={t('project_owner')}>
              <ComboBox options={(users || []).map((u) => ({ value: u.id, label: u.name }))} value={form.ownerUserId} onChange={(v) => setForm((f) => ({ ...f, ownerUserId: v }))} />
            </Field>
            <Field label={t('project_risk')}>
              <ComboBox options={['low', 'medium', 'high'].map((r) => ({ value: r, label: t(`risk_${r}`) }))} value={form.riskLevel} onChange={(v) => setForm((f) => ({ ...f, riskLevel: v }))} />
            </Field>
          </FieldRow>
          <FieldRow>
            <Field label={t('project_requesting_department')}>
              <ComboBox options={[{ value: '', label: '—' }, ...deptOptions]} value={form.requestingDepartmentId} onChange={(v) => setForm((f) => ({ ...f, requestingDepartmentId: v }))} />
            </Field>
            <Field label={t('project_responsible_department')}>
              <ComboBox options={[{ value: '', label: '—' }, ...deptOptions]} value={form.responsibleDepartmentId} onChange={(v) => setForm((f) => ({ ...f, responsibleDepartmentId: v }))} />
            </Field>
          </FieldRow>
          <FieldRow>
            <Field label={t('project_start_date')}>
              <input className="input" type="date" value={form.startDate} onChange={(e) => setForm((f) => ({ ...f, startDate: e.target.value }))} />
            </Field>
            <Field label={t('project_estimated_end_date')}>
              <input className="input" type="date" value={form.estimatedEndDate} onChange={(e) => setForm((f) => ({ ...f, estimatedEndDate: e.target.value }))} />
            </Field>
            <Field label={t('project_actual_end_date')}>
              <input className="input" type="date" value={form.actualEndDate} onChange={(e) => setForm((f) => ({ ...f, actualEndDate: e.target.value }))} />
            </Field>
          </FieldRow>
          <Field label={t('project_notes')}>
            <textarea className="textarea" value={form.notes} onChange={(e) => setForm((f) => ({ ...f, notes: e.target.value }))} />
          </Field>
        </div>
      )}

      <div className="panel-card">
        <h3>{t('project_members')}</h3>
        {project.members.map((m) => (
          <div key={m.user_id} style={{ display: 'flex', alignItems: 'center', gap: 10, padding: '6px 0' }}>
            <span style={{ flex: 1, fontSize: '.82rem' }}>{m.name} <span className="text-muted">· {m.email}</span></span>
            <button className="icon-btn" onClick={() => confirmRemoveMember(m)}><Trash2 size={16} /></button>
          </div>
        ))}
        <div style={{ display: 'flex', gap: 8, marginTop: 10 }}>
          <div style={{ flex: 1 }}>
            <ComboBox options={userOptions} value={addingMember} onChange={setAddingMember} placeholder={t('project_add_member')} />
          </div>
          <Button variant="standard" icon={UserPlus} onClick={addMember}>{t('project_add_member')}</Button>
        </div>
      </div>
    </div>
  );
}