import { useState } from "react";
import { Button, ContentSwitcher, InlineLoading, Select, SelectItem, Switch, Toggle } from "@carbon/react";
import { Catalog } from "@carbon/icons-react";
import { api } from "../lib/api";
import type { Settings } from "../lib/types";
import type { MarginPreset, PageId } from "../pdf/engine/geometry";
import { parsePrefs, prefsToJson, type RenderPrefsV1 } from "../pdf/model/prefs";
import { catalogEntry } from "../pdf/templates/catalog";
import TemplatePicker from "./TemplatePicker";

const PAGES: { id: PageId; label: string }[] = [
  { id: "A4", label: "A4" },
  { id: "LETTER", label: "US Letter" },
];

const MARGINS: { id: MarginPreset; label: string }[] = [
  { id: "template", label: "Template default" },
  { id: "narrow", label: "Narrow (0.5″)" },
  { id: "normal", label: "Normal (0.75″)" },
];

interface Props {
  prefs: RenderPrefsV1;
  onChange: (prefs: RenderPrefsV1) => void;
  /** Live settings; `renderPrefs` is the saved default. */
  settings: Settings;
  /** Called after the default was saved so the app reloads its settings. */
  onSaved: () => void;
  disabled?: boolean;
}

/** Page size and margins for the invoice being edited, plus "Save as default" for new invoices. */
export default function PageSetupControls({ prefs, onChange, settings, onSaved, disabled }: Props) {
  const [saving, setSaving] = useState(false);
  const [pickerOpen, setPickerOpen] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const saved = prefsToJson(parsePrefs(settings.renderPrefs));
  const isDefault = prefsToJson(prefs) === saved;
  const template = catalogEntry(prefs.templateId);

  const saveDefault = async () => {
    setSaving(true);
    setError(null);
    try {
      await api.saveSettings({ ...settings, renderPrefs: prefsToJson(prefs) });
      onSaved();
    } catch (e) {
      setError(String(e));
    } finally {
      setSaving(false);
    }
  };

  return (
    <div className="voiced-page-setup">
      <div className="voiced-page-setup__row">
        <div className="voiced-page-setup__field">
          <span className="cds--label">Template</span>
          <Button kind="tertiary" size="md" renderIcon={Catalog} disabled={disabled} onClick={() => setPickerOpen(true)}>
            {template.name}
          </Button>
        </div>
        <div className="voiced-page-setup__field">
          <span className="cds--label">Page size</span>
          <ContentSwitcher
            size="md"
            selectedIndex={Math.max(0, PAGES.findIndex((p) => p.id === prefs.pageSize))}
            onChange={(e) => !disabled && onChange({ ...prefs, pageSize: PAGES[e.index ?? 0].id })}
          >
            {PAGES.map((p) => (
              <Switch key={p.id} name={p.id} text={p.label} disabled={disabled} />
            ))}
          </ContentSwitcher>
        </div>
        <div className="voiced-page-setup__field">
          <Select
            id="page-margins"
            labelText="Margins"
            size="md"
            disabled={disabled}
            value={prefs.margins}
            onChange={(e) => onChange({ ...prefs, margins: e.target.value as MarginPreset })}
          >
            {MARGINS.map((m) => (
              <SelectItem key={m.id} value={m.id} text={m.label} />
            ))}
          </Select>
        </div>
      </div>
      {template.logoOptIn ? (
        <div className="voiced-page-setup__row voiced-page-setup__extra">
          <Toggle
            id="template-logo-show"
            size="sm"
            labelText="Logo"
            labelA="Hidden"
            labelB="Shown above the title"
            toggled={prefs.logo?.show === true}
            disabled={disabled}
            onToggle={(on) => onChange({ ...prefs, logo: { ...prefs.logo, show: on } })}
          />
        </div>
      ) : null}
      <TemplatePicker
        open={pickerOpen}
        onClose={() => setPickerOpen(false)}
        selectedId={template.id}
        onSelect={(id) => onChange({ ...prefs, templateId: id })}
        isDefault={isDefault}
        saving={saving}
        error={error}
        onSaveDefault={() => void saveDefault()}
        disabled={disabled}
      />
      <div className="voiced-page-setup__footer">
        {saving ? (
          <InlineLoading status="active" description="Saving…" />
        ) : (
          <Button kind="tertiary" size="sm" disabled={isDefault} onClick={() => void saveDefault()}>
            {isDefault ? "Saved as default" : "Save as default"}
          </Button>
        )}
        <span className="voiced-muted voiced-page-setup__note">
          {error ?? "This choice is frozen into each invoice when it is issued."}
        </span>
      </div>
    </div>
  );
}