with open('index.php', 'r', encoding='utf-8') as f:
    content = f.read()

start_str = "    const instanceModalElement = document.getElementById('instanceModal');\n    if (instanceModalElement) {\n        instanceModalElement.addEventListener('click', function(event) {\n            const btn = event.target.closest('#startProcessBtn');\n            if (!btn) return;"
end_str = "        });\n    }"

start_idx = content.find(start_str)
if start_idx != -1:
    end_idx = content.find(end_str, start_idx)
    if end_idx != -1:
        end_idx += len(end_str)
        
        replacement = "    const instanceModalElement = document.getElementById('instanceModal');\n    if (instanceModalElement) {\n        instanceModalElement.addEventListener('click', function(event) {\n            const startBtn = event.target.closest('#startProcessBtn');\n            const restartBtn = event.target.closest('#restartProcessBtn');\n            const btn = startBtn || restartBtn;\n            if (!btn) return;\n            \n            event.preventDefault();\n            event.stopPropagation();\n            \n            const isRestart = !!restartBtn;\n            \n            const personId = btn.dataset.personId;\n            const processId = btn.dataset.processId;\n            const processCode = btn.dataset.processCode;\n            \n            if (!personId) {\n                alert('Brak ID osoby');\n                return;\n            }\n            if (isRestart && !processCode) {\n                alert('Brak kodu procesu');\n                return;\n            }\n            if (!isRestart && !processId) {\n                alert('Brak ID procesu');\n                return;\n            }\n            \n            const originalText = btn.innerHTML;\n            btn.disabled = true;\n            btn.innerHTML = '<span class="spinner-border spinner-border-sm" role="status" aria-hidden="true"></span>...';\n            \n            const formData = new FormData();\n            formData.append('person_id', personId);\n            \n            if (isRestart) {\n                formData.append('process_code', processCode);\n                formData.append('mode', 'create_new_run');\n            } else {\n                formData.append('process_id', processId);\n            }\n            \n            if (instanceModalElement && processId) {\n                instanceModalElement.dataset.lastPersonId = personId;\n                instanceModalElement.dataset.lastProcessId = processId;\n            }\n            \n            fetch('_init_single_instance.php', {\n                method: 'POST',\n                body: formData\n            })\n            .then(async response => {\n                let data;\n                try {\n                    data = await response.json();\n                } catch (e) {\n                    throw new Error(`Błąd serwera (HTTP ${response.status}): Nieoczekiwany błąd (invalid JSON)`);\n                }\n                \n                if (!response.ok || !data.success) {\n                    let errMsg = data?.error?.message || data?.error || 'Nieznany błąd';\n                    if (data?.correlation_id) {\n                        errMsg += ` (ID błędu: ${data.correlation_id})`;\n                    }\n                    throw new Error(errMsg);\n                }\n                return data;\n            })\n            .then(data => {\n                const modalBody = instanceModalElement.querySelector('.modal-body');\n                modalBody.innerHTML = '<div class="text-center mt-4"><div class="spinner-border text-primary" role="status"></div><p class="mt-2">Ładowanie...</p></div>';\n                \n                const refreshProcessId = data.process_definition_id || processId || instanceModalElement.dataset.lastProcessId;\n                if (refreshProcessId) {\n                    instanceModalElement.dataset.lastProcessId = refreshProcessId;\n                }\n                \n                fetch(`_get_instance_details.php?person_id=${personId}&process_id=${refreshProcessId}`)\n                    .then(r => r.text())\n                    .then(html => {\n                        modalBody.innerHTML = html;\n                        window.matrixNeedsRefresh = true;\n                    });\n            })\n            .catch(err => {\n                console.error(err);\n                alert(err.message || 'Błąd sieci');\n                btn.disabled = false;\n                btn.innerHTML = originalText;\n            });\n        });\n    }"
        
        new_content = content[:start_idx] + replacement + content[end_idx:]
        with open('index.php', 'w', encoding='utf-8') as f:
            f.write(new_content)
        print("Replaced index.php block successfully.")
    else:
        print("End string not found.")
else:
    print("Start string not found.")