async function refreshCurrentViewPreservingScroll() {
  const scrollX = window.scrollX;
  const scrollY = window.scrollY;
  const response = await fetch(window.location.href, {
    credentials: 'same-origin',
    headers: { 'X-Requested-With': 'fetch' },
  });
  if (!response.ok) {
    throw new Error(`refresh_failed_${response.status}`);
  }

  const html = await response.text();
  const nextDocument = new DOMParser().parseFromString(html, 'text/html');
  ['.site-header', '.app-page-actions-wrap', 'main.page'].forEach((selector) => {
    const currentNode = document.querySelector(selector);
    const nextNode = nextDocument.querySelector(selector);
    if (currentNode && nextNode) {
      currentNode.replaceWith(nextNode);
    }
  });

  window.scrollTo({ left: scrollX, top: scrollY });
  if (typeof window.__stundenfuchsInitApp === 'function') {
    window.__stundenfuchsInitApp();
  }
}

function parseTimeToMinutes(value) {
  const match = /^(\d{2}):(\d{2})$/.exec(value || '');
  if (!match) {
    return null;
  }
  return Number(match[1]) * 60 + Number(match[2]);
}

function formatMinutesToTime(value) {
  const minutes = Math.max(0, Math.min(24 * 60 - 1, Number(value) || 0));
  const hoursPart = String(Math.floor(minutes / 60)).padStart(2, '0');
  const minutesPart = String(minutes % 60).padStart(2, '0');
  return `${hoursPart}:${minutesPart}`;
}

function requiredBreakMinutesForSpan(spanMinutes) {
  if (spanMinutes > 9 * 60) {
    return 45;
  }
  if (spanMinutes > 6 * 60) {
    return 30;
  }
  return 0;
}

function requiredBreakMinutesForNetMinutes(netMinutes) {
  if (netMinutes > (9 * 60 - 45)) {
    return 45;
  }
  if (netMinutes > (6 * 60 - 30)) {
    return 30;
  }
  return 0;
}

function initFullDayButtons() {
  document.querySelectorAll('[data-action="entry-apply-full-day"]').forEach((button) => {
    if (!(button instanceof HTMLButtonElement) || button.dataset.fullDayBound === 'true') {
      return;
    }
    button.dataset.fullDayBound = 'true';

    const form = button.closest('form[data-component="break-rules-form"]');
    if (!(form instanceof HTMLFormElement)) {
      return;
    }

    const startInput = form.querySelector('[data-break-input="start"]');
    const endInput = form.querySelector('[data-break-input="end"]');
    if (!(startInput instanceof HTMLInputElement) || !(endInput instanceof HTMLInputElement)) {
      return;
    }

    button.addEventListener('click', () => {
      const netMinutes = Number(form.dataset.fullDayNetMinutes || '');
      if (!Number.isFinite(netMinutes) || netMinutes <= 0) {
        return;
      }

      const defaultStartValue = form.dataset.defaultStartTime || '08:30';
      const startMinutes = parseTimeToMinutes(startInput.value) ?? parseTimeToMinutes(defaultStartValue);
      if (startMinutes === null) {
        return;
      }

      const autoBreakEnabled = form.dataset.autoBreakEnabled === 'true';
      const configuredBreakMinutes = Number(form.dataset.defaultBreakMinutes || '0');
      const breakMinutes = autoBreakEnabled
        ? requiredBreakMinutesForNetMinutes(netMinutes)
        : Math.max(0, configuredBreakMinutes);
      const endMinutes = startMinutes + netMinutes + breakMinutes;

      startInput.value = formatMinutesToTime(startMinutes);
      endInput.value = formatMinutesToTime(endMinutes);
    });
  });
}

function initBreakRuleForms() {
  document.querySelectorAll('form[data-component="break-rules-form"]').forEach((form) => {
    if (form.dataset.breakBound === 'true') {
      return;
    }
    form.dataset.breakBound = 'true';
    const autoBreakEnabled = form.dataset.autoBreakEnabled === 'true';

    const modeInput = form.querySelector('[data-break-mode]');
    const startInput = form.querySelector('[data-break-input="start"]');
    const endInput = form.querySelector('[data-break-input="end"]');
    const breakInput = form.querySelector('[data-break-input="minutes"]');
    const statusNode = form.querySelector('[data-break-status]');
    const resetButton = form.querySelector('[data-action="break-reset-auto"]');

    if (!(modeInput instanceof HTMLInputElement) || !(startInput instanceof HTMLInputElement) || !(endInput instanceof HTMLInputElement)) {
      return;
    }

    const updateStatus = () => {
      if (!statusNode) {
        return;
      }
      statusNode.textContent = modeInput.value === 'manual'
        ? 'Pause manuell gesetzt. Gesetzliche Mindestpause wird nicht automatisch überschrieben.'
        : 'Gesetzliche Mindestpause nach deutschem Arbeitsrecht wird automatisch vorgeschlagen.';
    };

    const applyAutoBreak = () => {
      if (!(breakInput instanceof HTMLInputElement)) {
        return;
      }
      const startMinutes = parseTimeToMinutes(startInput.value);
      const endMinutes = parseTimeToMinutes(endInput.value);
      if (startMinutes === null || endMinutes === null || endMinutes <= startMinutes) {
        return;
      }
      modeInput.value = 'auto';
      breakInput.value = String(requiredBreakMinutesForSpan(endMinutes - startMinutes));
      updateStatus();
    };

    const setManualMode = () => {
      modeInput.value = 'manual';
      updateStatus();
    };

    startInput.addEventListener('input', () => {
      if (modeInput.value === 'auto') {
        applyAutoBreak();
      }
    });
    endInput.addEventListener('input', () => {
      if (modeInput.value === 'auto') {
        applyAutoBreak();
      }
    });
    if (breakInput instanceof HTMLInputElement) {
      breakInput.addEventListener('input', setManualMode);
    }
    if (resetButton) {
      resetButton.addEventListener('click', applyAutoBreak);
    }

    if (!autoBreakEnabled) {
      return;
    }
    if (!modeInput.value) {
      modeInput.value = 'auto';
    }
    if (modeInput.value === 'auto') {
      applyAutoBreak();
    } else {
      updateStatus();
    }
  });
}

function initAsyncRefreshForms() {
  document.querySelectorAll('form[data-async-refresh="view"]').forEach((form) => {
    if (form.dataset.asyncBound === 'true') {
      return;
    }
    form.dataset.asyncBound = 'true';
    form.addEventListener('submit', async (event) => {
      event.preventDefault();
      const submitter = event.submitter instanceof HTMLElement ? event.submitter : null;
      if (submitter) {
        submitter.setAttribute('disabled', 'disabled');
      }

      try {
        const response = await fetch(form.action, {
          method: 'POST',
          body: new FormData(form),
          credentials: 'same-origin',
          headers: { 'X-Requested-With': 'fetch' },
        });
        if (!response.ok) {
          throw new Error(`submit_failed_${response.status}`);
        }
        await refreshCurrentViewPreservingScroll();
      } catch (error) {
        window.location.assign(window.location.href);
      } finally {
        if (submitter) {
          submitter.removeAttribute('disabled');
        }
      }
    });
  });
}

function initBreakSettingsForms() {
  document.querySelectorAll('form[data-component="break-settings-form"]').forEach((form) => {
    if (form.dataset.breakSettingsBound === 'true') {
      return;
    }
    form.dataset.breakSettingsBound = 'true';

    const toggle = form.querySelector('[data-break-settings-toggle]');
    const minutesInput = form.querySelector('[data-break-settings-minutes]');

    if (!(toggle instanceof HTMLInputElement) || !(minutesInput instanceof HTMLInputElement)) {
      return;
    }

    const syncDisabledState = () => {
      minutesInput.disabled = toggle.checked;
    };

    toggle.addEventListener('change', syncDisabledState);
    syncDisabledState();
  });
}

export function initForms() {
  document.querySelectorAll('form[data-confirm]').forEach((form) => {
    form.addEventListener('submit', (event) => {
      const message = form.getAttribute('data-confirm') || 'Aktion wirklich ausführen?';
      if (!window.confirm(message)) {
        event.preventDefault();
      }
    });
  });
  initAsyncRefreshForms();
  initFullDayButtons();
  initBreakRuleForms();
  initBreakSettingsForms();
}