import { createResource, createSignal, Show, For } from 'solid-js';
import AdminShell from '~/components/AdminShell';

const API = '/api/gateway';

const ROLE_OPTIONS = [
  'company',
  'customer',
  'job_seeker',
  'photographer',
  'video_editor',
  'graphic_designer',
  'social_media_manager',
  'fitness_trainer',
  'catering_services',
  'makeup_artist',
  'tutor',
  'developer',
];

type Coupon = {
  id: string;
  code: string;
  title: string;
  type: 'PERCENT' | 'FIXED';
  value: number;
  min_order_amount: number;
  used_count: number;
  usage_limit?: number;
  is_active: boolean;
  role_keys: string[];
};

async function loadCoupons(): Promise<Coupon[]> {
  try {
    const res = await fetch(`${API}/api/admin/coupons`);
    if (!res.ok) throw new Error('Failed to load');
    const data = await res.json();
    return Array.isArray(data) ? data : (data.coupons || []);
  } catch {
    return [];
  }
}

const defaultForm = () => ({
  id: '',
  code: '',
  title: '',
  type: 'PERCENT' as 'PERCENT' | 'FIXED',
  value: 10,
  min_order_amount: 0,
  max_uses: '',
  role_keys: ['company', 'customer'] as string[],
});

export default function CouponPage() {
  const [coupons, { refetch }] = createResource(loadCoupons);
  const [activeTab, setActiveTab] = createSignal<'list' | 'create'>('list');
  const [form, setForm] = createSignal(defaultForm());
  const [saving, setSaving] = createSignal(false);
  const [toggling, setToggling] = createSignal('');
  const [formError, setFormError] = createSignal('');

  const resetForm = () => {
    setForm(defaultForm());
    setFormError('');
  };

  const startEdit = (coupon: Coupon) => {
    setForm({
      id: coupon.id,
      code: coupon.code,
      title: coupon.title || '',
      type: coupon.type,
      value: coupon.value,
      min_order_amount: coupon.min_order_amount || 0,
      max_uses: coupon.usage_limit != null ? String(coupon.usage_limit) : '',
      role_keys: Array.isArray(coupon.role_keys) ? coupon.role_keys : [],
    });
    setActiveTab('create');
  };

  const toggleRole = (role: string) => {
    const current = form().role_keys;
    if (current.includes(role)) {
      setForm({ ...form(), role_keys: current.filter((r) => r !== role) });
    } else {
      setForm({ ...form(), role_keys: [...current, role] });
    }
  };

  const handleSave = async (e: Event) => {
    e.preventDefault();
    try {
      setSaving(true);
      setFormError('');
      const f = form();
      const body: Record<string, unknown> = {
        code: f.code.toUpperCase(),
        title: f.title,
        type: f.type,
        value: Number(f.value),
        min_order_amount: Number(f.min_order_amount),
        role_keys: f.role_keys,
      };
      if (f.max_uses) body.max_uses = Number(f.max_uses);

      const url = f.id ? `${API}/api/admin/coupons/${f.id}` : `${API}/api/admin/coupons`;
      const method = f.id ? 'PATCH' : 'POST';
      const res = await fetch(url, {
        method,
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(body),
      });
      if (!res.ok) throw new Error('Failed to save coupon');
      resetForm();
      refetch();
      setActiveTab('list');
    } catch (err: unknown) {
      setFormError(err instanceof Error ? err.message : 'Failed to save');
    } finally {
      setSaving(false);
    }
  };

  const handleToggle = async (coupon: Coupon) => {
    try {
      setToggling(coupon.id);
      const res = await fetch(`${API}/api/admin/coupons/${coupon.id}`, {
        method: 'PATCH',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ is_active: !coupon.is_active }),
      });
      if (!res.ok) throw new Error('Failed to toggle');
      refetch();
    } catch {
      // ignore
    } finally {
      setToggling('');
    }
  };

  return (
    <AdminShell>
      <div class="page-actions">
        <div>
          <h1 class="page-title">Coupon Management</h1>
          <p class="page-subtitle">Reusable coupon codes for package checkout</p>
        </div>
      </div>

      {/* Tabs */}
      <div style="display:flex;border-bottom:2px solid #e2e8f0;margin-bottom:24px;gap:0;overflow-x:auto;">
        <button
          type="button"
          class={`admin-tab${activeTab() === 'list' ? ' active' : ''}`}
          onClick={() => setActiveTab('list')}
        >
          Coupons
        </button>
        <button
          type="button"
          class={`admin-tab${activeTab() === 'create' ? ' active' : ''}`}
          onClick={() => { resetForm(); setActiveTab('create'); }}
        >
          {form().id ? 'Edit Coupon' : 'Create Coupon'}
        </button>
      </div>

      <Show when={activeTab() === 'list'}>
        <section class="card" style="padding: 0; overflow: hidden;">
          <div class="table-wrap">
            <table class="list-table">
              <thead>
                <tr>
                  <th>Code</th>
                  <th>Title</th>
                  <th>Type</th>
                  <th>Value</th>
                  <th>Max Uses</th>
                  <th>Status</th>
                  <th class="align-right">Actions</th>
                </tr>
              </thead>
              <tbody>
                <Show when={coupons.loading}>
                  <tr><td colspan="7" style="text-align:center;padding:32px;color:#64748b">Loading...</td></tr>
                </Show>
                <Show when={!coupons.loading && coupons.error}>
                  <tr><td colspan="7" style="text-align:center;padding:32px;color:#b91c1c">Failed to load. Is the backend running?</td></tr>
                </Show>
                <Show when={!coupons.loading && !coupons.error && coupons()?.length === 0}>
                  <tr><td colspan="7" style="text-align:center;padding:32px;color:#94a3b8">No coupons found.</td></tr>
                </Show>
                <Show when={!coupons.loading && !coupons.error && (coupons()?.length ?? 0) > 0}>
                  <For each={coupons()}>
                    {(item) => (
                      <tr>
                        <td style="font-weight:600;color:#0f172a;font-family:monospace">{item.code}</td>
                        <td style="color:#475569">{item.title || '—'}</td>
                        <td style="color:#475569">{item.type}</td>
                        <td style="color:#475569">{item.type === 'PERCENT' ? `${item.value}%` : `₹${item.value}`}</td>
                        <td style="color:#475569">{item.usage_limit != null ? item.usage_limit : '—'}</td>
                        <td>
                          <span class={`status-chip ${item.is_active ? 'active' : ''}`}>
                            {item.is_active ? 'Active' : 'Inactive'}
                          </span>
                        </td>
                        <td>
                          <div class="table-actions">
                            <button class="btn" onClick={() => startEdit(item)}>Edit</button>
                            <button
                              class="btn"
                              disabled={toggling() === item.id}
                              onClick={() => handleToggle(item)}
                            >
                              {toggling() === item.id ? '...' : (item.is_active ? 'Disable' : 'Enable')}
                            </button>
                          </div>
                        </td>
                      </tr>
                    )}
                  </For>
                </Show>
              </tbody>
            </table>
          </div>
        </section>
      </Show>

      <Show when={activeTab() === 'create'}>
        <section class="card" style="max-width:520px">
          <h2 style="margin:0 0 20px;font-size:16px;font-weight:700">{form().id ? 'Edit Coupon' : 'Create Coupon'}</h2>
          <Show when={formError()}>
            <div class="error-box" style="margin-bottom:12px">{formError()}</div>
          </Show>
          <form onSubmit={handleSave} style="display:flex;flex-direction:column;gap:14px">
            <div class="field">
              <label>Code</label>
              <input
                type="text"
                value={form().code}
                onInput={(e) => setForm({ ...form(), code: e.currentTarget.value.toUpperCase() })}
                required
                placeholder="e.g. SAVE10"
                style="text-transform:uppercase"
              />
            </div>
            <div class="field">
              <label>Title</label>
              <input
                type="text"
                value={form().title}
                onInput={(e) => setForm({ ...form(), title: e.currentTarget.value })}
                required
                placeholder="e.g. 10% off for companies"
              />
            </div>
            <div class="field-grid-2">
              <div class="field">
                <label>Type</label>
                <select
                  value={form().type}
                  onChange={(e) => setForm({ ...form(), type: e.currentTarget.value as 'PERCENT' | 'FIXED' })}
                >
                  <option value="PERCENT">Percent (%)</option>
                  <option value="FIXED">Fixed (₹)</option>
                </select>
              </div>
              <div class="field">
                <label>Value</label>
                <input
                  type="number"
                  value={form().value}
                  onInput={(e) => setForm({ ...form(), value: Number(e.currentTarget.value) })}
                  required
                  min="1"
                />
              </div>
            </div>
            <div class="field-grid-2">
              <div class="field">
                <label>Min Order Amount (₹)</label>
                <input
                  type="number"
                  value={form().min_order_amount}
                  onInput={(e) => setForm({ ...form(), min_order_amount: Number(e.currentTarget.value) })}
                  min="0"
                  placeholder="0"
                />
              </div>
              <div class="field">
                <label>Max Uses (blank = unlimited)</label>
                <input
                  type="number"
                  value={form().max_uses}
                  onInput={(e) => setForm({ ...form(), max_uses: e.currentTarget.value })}
                  min="1"
                  placeholder="Unlimited"
                />
              </div>
            </div>
            <div>
              <p style="font-size:13px;font-weight:600;margin:0 0 8px;color:#1e293b">Applicable Roles</p>
              <div style="display:flex;flex-wrap:wrap;gap:8px">
                <For each={ROLE_OPTIONS}>
                  {(role) => {
                    const active = () => form().role_keys.includes(role);
                    return (
                      <button
                        type="button"
                        onClick={() => toggleRole(role)}
                        style={`border-radius:999px;padding:4px 14px;font-size:13px;cursor:pointer;border:1px solid ${active() ? '#fdba74' : '#cbd5e1'};background:${active() ? '#fff7ed' : '#fff'};color:${active() ? '#c2410c' : '#475569'}`}
                      >
                        {role}
                      </button>
                    );
                  }}
                </For>
              </div>
            </div>
            <div class="actions">
              <button class="btn navy" type="submit" disabled={saving()}>
                {saving() ? 'Saving...' : (form().id ? 'Update Coupon' : 'Save Coupon')}
              </button>
              <Show when={form().id}>
                <button type="button" class="btn" onClick={resetForm}>Cancel Edit</button>
              </Show>
            </div>
          </form>
        </section>
      </Show>
    </AdminShell>
  );
}