---
name: pdf
description: Processamento completo de ficheiros PDF — leitura, extraccao de texto/tabelas, merge, split, watermarks, encriptacao, OCR, criacao e preenchimento de formularios.
---

# PDF Processing Guide

## Resumo

Guia completo para processamento de PDFs com bibliotecas Python e ferramentas de linha de comandos. Para formularios PDF, seguir as instruccoes na seccao "Preenchimento de formularios". Para funcionalidades avancadas e bibliotecas JavaScript, consultar a seccao "Referencia avancada".

## Quick Start

```python
from pypdf import PdfReader, PdfWriter

# Read a PDF
reader = PdfReader("/media/ealmeida/Dados/GDrive/Cloud/Descomplicar/documento.pdf")
print(f"Pages: {len(reader.pages)}")

# Extract text
text = ""
for page in reader.pages:
    text += page.extract_text()
```

## Bibliotecas Python

### pypdf — operacoes basicas

#### Merge PDFs
```python
from pypdf import PdfWriter, PdfReader

writer = PdfWriter()
for pdf_file in ["doc1.pdf", "doc2.pdf", "doc3.pdf"]:
    reader = PdfReader(pdf_file)
    for page in reader.pages:
        writer.add_page(page)

with open("merged.pdf", "wb") as output:
    writer.write(output)
```

#### Split PDF
```python
reader = PdfReader("input.pdf")
for i, page in enumerate(reader.pages):
    writer = PdfWriter()
    writer.add_page(page)
    with open(f"page_{i+1}.pdf", "wb") as output:
        writer.write(output)
```

#### Extract Metadata
```python
reader = PdfReader("document.pdf")
meta = reader.metadata
print(f"Title: {meta.title}")
print(f"Author: {meta.author}")
print(f"Subject: {meta.subject}")
print(f"Creator: {meta.creator}")
```

#### Rotate Pages
```python
reader = PdfReader("input.pdf")
writer = PdfWriter()

page = reader.pages[0]
page.rotate(90)  # Rotate 90 degrees clockwise
writer.add_page(page)

with open("rotated.pdf", "wb") as output:
    writer.write(output)
```

### pdfplumber — extraccao de texto e tabelas

#### Extract Text with Layout
```python
import pdfplumber

with pdfplumber.open("document.pdf") as pdf:
    for page in pdf.pages:
        text = page.extract_text()
        print(text)
```

#### Extract Tables
```python
with pdfplumber.open("document.pdf") as pdf:
    for i, page in enumerate(pdf.pages):
        tables = page.extract_tables()
        for j, table in enumerate(tables):
            print(f"Table {j+1} on page {i+1}:")
            for row in table:
                print(row)
```

#### Advanced Table Extraction
```python
import pandas as pd

with pdfplumber.open("document.pdf") as pdf:
    all_tables = []
    for page in pdf.pages:
        tables = page.extract_tables()
        for table in tables:
            if table:  # Check if table is not empty
                df = pd.DataFrame(table[1:], columns=table[0])
                all_tables.append(df)

# Combine all tables
if all_tables:
    combined_df = pd.concat(all_tables, ignore_index=True)
    combined_df.to_excel("extracted_tables.xlsx", index=False)
```

### reportlab — criacao de PDFs

#### Basic PDF Creation
```python
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas

c = canvas.Canvas("hello.pdf", pagesize=letter)
width, height = letter

# Add text
c.drawString(100, height - 100, "Hello World!")
c.drawString(100, height - 120, "This is a PDF created with reportlab")

# Add a line
c.line(100, height - 140, 400, height - 140)

# Save
c.save()
```

#### Create PDF with Multiple Pages
```python
from reportlab.lib.pagesizes import letter
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, PageBreak
from reportlab.lib.styles import getSampleStyleSheet

doc = SimpleDocTemplate("report.pdf", pagesize=letter)
styles = getSampleStyleSheet()
story = []

# Add content
title = Paragraph("Report Title", styles['Title'])
story.append(title)
story.append(Spacer(1, 12))

body = Paragraph("This is the body of the report. " * 20, styles['Normal'])
story.append(body)
story.append(PageBreak())

# Page 2
story.append(Paragraph("Page 2", styles['Heading1']))
story.append(Paragraph("Content for page 2", styles['Normal']))

# Build PDF
doc.build(story)
```

#### Subscripts and Superscripts

**Importante**: nunca usar caracteres Unicode subscript/superscript (subscript: 0-9, superscript: 0-9) em PDFs ReportLab. As fontes built-in nao incluem estes glifos, resultando em caixas pretas.

Usar as tags XML do ReportLab em objectos Paragraph:
```python
from reportlab.platypus import Paragraph
from reportlab.lib.styles import getSampleStyleSheet

styles = getSampleStyleSheet()

# Subscripts: use <sub> tag
chemical = Paragraph("H<sub>2</sub>O", styles['Normal'])

# Superscripts: use <super> tag
squared = Paragraph("x<super>2</super> + y<super>2</super>", styles['Normal'])
```

Para texto desenhado com canvas (nao Paragraph), ajustar manualmente o tamanho da fonte e posicao.

## Ferramentas de linha de comandos

### pdftotext (poppler-utils)
```bash
# Extract text
pdftotext input.pdf output.txt

# Extract text preserving layout
pdftotext -layout input.pdf output.txt

# Extract specific pages
pdftotext -f 1 -l 5 input.pdf output.txt  # Pages 1-5
```

### qpdf
```bash
# Merge PDFs
qpdf --empty --pages file1.pdf file2.pdf -- merged.pdf

# Split pages
qpdf input.pdf --pages . 1-5 -- pages1-5.pdf
qpdf input.pdf --pages . 6-10 -- pages6-10.pdf

# Rotate pages
qpdf input.pdf output.pdf --rotate=+90:1  # Rotate page 1 by 90 degrees

# Remove password
qpdf --password=mypassword --decrypt encrypted.pdf decrypted.pdf
```

### pdftk (if available)
```bash
# Merge
pdftk file1.pdf file2.pdf cat output merged.pdf

# Split
pdftk input.pdf burst

# Rotate
pdftk input.pdf rotate 1east output rotated.pdf
```

## Tarefas comuns

### Extrair texto de PDFs digitalizados (OCR)
```python
# Requires: pip install pytesseract pdf2image
import pytesseract
from pdf2image import convert_from_path

# Convert PDF to images
images = convert_from_path('scanned.pdf')

# OCR each page
text = ""
for i, image in enumerate(images):
    text += f"Page {i+1}:\n"
    text += pytesseract.image_to_string(image)
    text += "\n\n"

print(text)
```

### Adicionar watermark
```python
from pypdf import PdfReader, PdfWriter

# Create watermark (or load existing)
watermark = PdfReader("watermark.pdf").pages[0]

# Apply to all pages
reader = PdfReader("document.pdf")
writer = PdfWriter()

for page in reader.pages:
    page.merge_page(watermark)
    writer.add_page(page)

with open("watermarked.pdf", "wb") as output:
    writer.write(output)
```

### Extrair imagens
```bash
# Using pdfimages (poppler-utils)
pdfimages -j input.pdf output_prefix

# This extracts all images as output_prefix-000.jpg, output_prefix-001.jpg, etc.
```

### Proteccao por password
```python
from pypdf import PdfReader, PdfWriter

reader = PdfReader("input.pdf")
writer = PdfWriter()

for page in reader.pages:
    writer.add_page(page)

# Add password
writer.encrypt("userpassword", "ownerpassword")

with open("encrypted.pdf", "wb") as output:
    writer.write(output)
```

## Referencia rapida

| Tarefa | Melhor ferramenta | Comando/codigo |
|--------|-------------------|----------------|
| Merge PDFs | pypdf | `writer.add_page(page)` |
| Split PDFs | pypdf | One page per file |
| Extrair texto | pdfplumber | `page.extract_text()` |
| Extrair tabelas | pdfplumber | `page.extract_tables()` |
| Criar PDFs | reportlab | Canvas or Platypus |
| Merge CLI | qpdf | `qpdf --empty --pages ...` |
| OCR scanned PDFs | pytesseract | Convert to image first |
| Preencher formularios | pypdf ou annotations | Ver seccao abaixo |

---

## Preenchimento de formularios

**Obrigatorio: seguir estes passos por ordem. Nao saltar para codigo directamente.**

Primeiro verificar se o PDF tem campos preenchíveis. Executar a partir da pasta de scripts desta skill:
`python scripts/check_fillable_fields.py <file.pdf>`

Consoante o resultado, seguir a seccao "Campos preenchíveis" ou "Campos nao preenchíveis".

### Campos preenchíveis

Se o PDF tiver campos de formulario nativos:

1. Extrair informacao dos campos:
`python scripts/extract_form_field_info.py <input.pdf> <field_info.json>`

O JSON resultante contem campos com esta estrutura:
```json
[
  {
    "field_id": "(ID unico do campo)",
    "page": "(numero da pagina, 1-based)",
    "rect": "[left, bottom, right, top]",
    "type": "text | checkbox | radio_group | choice"
  }
]
```

Para **checkboxes**: propriedades `checked_value` e `unchecked_value`.
Para **radio groups**: lista `radio_options` com `value` e `rect`.
Para **choice fields**: lista `choice_options` com `value` e `text`.

2. Converter PDF para imagens para analise visual:
`python scripts/convert_pdf_to_images.py <file.pdf> <output_directory>`
Analisar as imagens para determinar o proposito de cada campo.

3. Criar `field_values.json`:
```json
[
  {
    "field_id": "last_name",
    "description": "Apelido do utilizador",
    "page": 1,
    "value": "Silva"
  },
  {
    "field_id": "Checkbox12",
    "description": "Checkbox para maiores de 18",
    "page": 1,
    "value": "/On"
  }
]
```

4. Preencher:
`python scripts/fill_fillable_fields.py <input.pdf> <field_values.json> <output.pdf>`

### Campos nao preenchíveis

Se o PDF nao tiver campos nativos, usar anotacoes de texto. Tentar primeiro extraccao por estrutura (mais preciso), depois estimativa visual como fallback.

#### Passo 1: extraccao por estrutura

`python scripts/extract_form_structure.py <input.pdf> form_structure.json`

Extrai labels de texto, linhas horizontais e checkboxes com coordenadas exactas.

**Se form_structure.json tiver labels significativos** -> usar abordagem A (estrutura).
**Se o PDF for digitalizado/imagem** -> usar abordagem B (visual).

#### Abordagem A: coordenadas por estrutura (preferida)

Analisar form_structure.json e identificar:
- **Label groups**: elementos de texto adjacentes que formam um label
- **Row structure**: labels com `top` similar estao na mesma linha
- **Field columns**: areas de entrada comecam apos o label (x0 = label.x1 + gap)
- **Checkboxes**: usar coordenadas directamente do JSON

Criar fields.json com `pdf_width`/`pdf_height`:
```json
{
  "pages": [
    {"page_number": 1, "pdf_width": 612, "pdf_height": 792}
  ],
  "form_fields": [
    {
      "page_number": 1,
      "description": "Campo apelido",
      "field_label": "Apelido",
      "label_bounding_box": [43, 63, 87, 73],
      "entry_bounding_box": [92, 63, 260, 79],
      "entry_text": {"text": "Silva", "font_size": 10}
    }
  ]
}
```

#### Abordagem B: estimativa visual (fallback)

1. Converter PDF para imagens:
`python scripts/convert_pdf_to_images.py <input.pdf> <images_dir/>`

2. Identificar campos e posicoes aproximadas nas imagens.

3. Refinar com zoom (ImageMagick):
```bash
magick <page_image> -crop <width>x<height>+<x>+<y> +repage <crop_output.png>
```

Converter coordenadas do crop de volta para coordenadas da imagem completa:
- full_x = crop_x + crop_offset_x
- full_y = crop_y + crop_offset_y

4. Criar fields.json com `image_width`/`image_height`.

#### Abordagem hibrida

Quando a extraccao por estrutura funciona para a maioria dos campos mas falta alguns:
1. Usar abordagem A para campos detectados
2. Usar abordagem B para campos em falta
3. Converter todas as coordenadas para PDF:
   - pdf_x = image_x * (pdf_width / image_width)
   - pdf_y = image_y * (pdf_height / image_height)
4. Usar sistema de coordenadas unico com `pdf_width`/`pdf_height`

#### Validacao e preenchimento

Validar bounding boxes antes de preencher:
`python scripts/check_bounding_boxes.py fields.json`

Preencher o formulario:
`python scripts/fill_pdf_form_with_annotations.py <input.pdf> fields.json <output.pdf>`

Verificar resultado:
`python scripts/convert_pdf_to_images.py <output.pdf> <verify_images/>`

Criar imagem de validacao com bounding boxes sobrepostas:
`python scripts/create_validation_image.py <page_number> <fields.json> <input_image> <output_image>`

---

## Referencia avancada

### pypdfium2 — rendering rapido

```python
import pypdfium2 as pdfium
from PIL import Image

# Load PDF
pdf = pdfium.PdfDocument("document.pdf")

# Render page to image
page = pdf[0]
bitmap = page.render(scale=2.0, rotation=0)
img = bitmap.to_pil()
img.save("page_1.png", "PNG")

# Process multiple pages
for i, page in enumerate(pdf):
    bitmap = page.render(scale=1.5)
    img = bitmap.to_pil()
    img.save(f"page_{i+1}.jpg", "JPEG", quality=90)
```

### pdfplumber — funcionalidades avancadas

#### Texto com coordenadas precisas
```python
import pdfplumber

with pdfplumber.open("document.pdf") as pdf:
    page = pdf.pages[0]

    # Extract all text with coordinates
    chars = page.chars
    for char in chars[:10]:
        print(f"Char: '{char['text']}' at x:{char['x0']:.1f} y:{char['y0']:.1f}")

    # Extract text by bounding box (left, top, right, bottom)
    bbox_text = page.within_bbox((100, 100, 400, 200)).extract_text()
```

#### Tabelas complexas com settings customizados
```python
import pdfplumber
import pandas as pd

with pdfplumber.open("complex_table.pdf") as pdf:
    page = pdf.pages[0]

    table_settings = {
        "vertical_strategy": "lines",
        "horizontal_strategy": "lines",
        "snap_tolerance": 3,
        "intersection_tolerance": 15
    }
    tables = page.extract_tables(table_settings)

    # Visual debugging for table extraction
    img = page.to_image(resolution=150)
    img.save("debug_layout.png")
```

### reportlab — relatorios profissionais com tabelas

```python
from reportlab.platypus import SimpleDocTemplate, Table, TableStyle, Paragraph
from reportlab.lib.styles import getSampleStyleSheet
from reportlab.lib import colors

data = [
    ['Produto', 'Q1', 'Q2', 'Q3', 'Q4'],
    ['Widgets', '120', '135', '142', '158'],
    ['Gadgets', '85', '92', '98', '105']
]

doc = SimpleDocTemplate("report.pdf")
elements = []

styles = getSampleStyleSheet()
title = Paragraph("Relatorio Trimestral de Vendas", styles['Title'])
elements.append(title)

table = Table(data)
table.setStyle(TableStyle([
    ('BACKGROUND', (0, 0), (-1, 0), colors.grey),
    ('TEXTCOLOR', (0, 0), (-1, 0), colors.whitesmoke),
    ('ALIGN', (0, 0), (-1, -1), 'CENTER'),
    ('FONTNAME', (0, 0), (-1, 0), 'Helvetica-Bold'),
    ('FONTSIZE', (0, 0), (-1, 0), 14),
    ('BOTTOMPADDING', (0, 0), (-1, 0), 12),
    ('BACKGROUND', (0, 1), (-1, -1), colors.beige),
    ('GRID', (0, 0), (-1, -1), 1, colors.black)
]))
elements.append(table)

doc.build(elements)
```

### JavaScript — pdf-lib (criacao e modificacao)

#### Load and Manipulate Existing PDF
```javascript
import { PDFDocument } from 'pdf-lib';
import fs from 'fs';

async function manipulatePDF() {
    const existingPdfBytes = fs.readFileSync('input.pdf');
    const pdfDoc = await PDFDocument.load(existingPdfBytes);

    const pageCount = pdfDoc.getPageCount();
    const newPage = pdfDoc.addPage([600, 400]);
    newPage.drawText('Added by pdf-lib', { x: 100, y: 300, size: 16 });

    const pdfBytes = await pdfDoc.save();
    fs.writeFileSync('modified.pdf', pdfBytes);
}
```

#### Advanced Merge and Split
```javascript
import { PDFDocument } from 'pdf-lib';
import fs from 'fs';

async function mergePDFs() {
    const mergedPdf = await PDFDocument.create();

    const pdf1 = await PDFDocument.load(fs.readFileSync('doc1.pdf'));
    const pdf2 = await PDFDocument.load(fs.readFileSync('doc2.pdf'));

    const pdf1Pages = await mergedPdf.copyPages(pdf1, pdf1.getPageIndices());
    pdf1Pages.forEach(page => mergedPdf.addPage(page));

    const pdf2Pages = await mergedPdf.copyPages(pdf2, [0, 2, 4]);
    pdf2Pages.forEach(page => mergedPdf.addPage(page));

    fs.writeFileSync('merged.pdf', await mergedPdf.save());
}
```

### Operacoes avancadas CLI

#### poppler-utils
```bash
# Text with bounding box coordinates
pdftotext -bbox-layout document.pdf output.xml

# High-resolution PNG conversion
pdftoppm -png -r 300 document.pdf output_prefix

# Specific page range with high resolution
pdftoppm -png -r 600 -f 1 -l 3 document.pdf high_res_pages

# Extract all embedded images with metadata
pdfimages -j -p document.pdf page_images

# List image info without extracting
pdfimages -list document.pdf
```

#### qpdf avancado
```bash
# Split PDF into groups of pages
qpdf --split-pages=3 input.pdf output_group_%02d.pdf

# Complex page ranges from multiple PDFs
qpdf --empty --pages doc1.pdf 1-3 doc2.pdf 5-7 doc3.pdf 2,4 -- combined.pdf

# Optimize for web (linearize)
qpdf --linearize input.pdf optimized.pdf

# Repair corrupted PDF
qpdf --check input.pdf
qpdf --fix-qdf damaged.pdf repaired.pdf

# Advanced encryption with permissions
qpdf --encrypt user_pass owner_pass 256 --print=none --modify=none -- input.pdf encrypted.pdf

# Check encryption status
qpdf --show-encryption encrypted.pdf
```

### Processamento em lote com error handling

```python
import os
import glob
from pypdf import PdfReader, PdfWriter
import logging

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

def batch_process_pdfs(input_dir, operation='merge'):
    pdf_files = glob.glob(os.path.join(input_dir, "*.pdf"))

    if operation == 'merge':
        writer = PdfWriter()
        for pdf_file in pdf_files:
            try:
                reader = PdfReader(pdf_file)
                for page in reader.pages:
                    writer.add_page(page)
                logger.info(f"Processed: {pdf_file}")
            except Exception as e:
                logger.error(f"Failed to process {pdf_file}: {e}")
                continue

        with open("batch_merged.pdf", "wb") as output:
            writer.write(output)

    elif operation == 'extract_text':
        for pdf_file in pdf_files:
            try:
                reader = PdfReader(pdf_file)
                text = ""
                for page in reader.pages:
                    text += page.extract_text()

                output_file = pdf_file.replace('.pdf', '.txt')
                with open(output_file, 'w', encoding='utf-8') as f:
                    f.write(text)
                logger.info(f"Extracted text from: {pdf_file}")
            except Exception as e:
                logger.error(f"Failed to extract text from {pdf_file}: {e}")
                continue
```

### Cropping avancado

```python
from pypdf import PdfWriter, PdfReader

reader = PdfReader("input.pdf")
writer = PdfWriter()

page = reader.pages[0]
page.mediabox.left = 50
page.mediabox.bottom = 50
page.mediabox.right = 550
page.mediabox.top = 750

writer.add_page(page)
with open("cropped.pdf", "wb") as output:
    writer.write(output)
```

### Gestao de memoria para PDFs grandes

```python
def process_large_pdf(pdf_path, chunk_size=10):
    reader = PdfReader(pdf_path)
    total_pages = len(reader.pages)

    for start_idx in range(0, total_pages, chunk_size):
        end_idx = min(start_idx + chunk_size, total_pages)
        writer = PdfWriter()

        for i in range(start_idx, end_idx):
            writer.add_page(reader.pages[i])

        with open(f"chunk_{start_idx//chunk_size}.pdf", "wb") as output:
            writer.write(output)
```

## Troubleshooting

### PDFs encriptados
```python
from pypdf import PdfReader

try:
    reader = PdfReader("encrypted.pdf")
    if reader.is_encrypted:
        reader.decrypt("password")
except Exception as e:
    print(f"Failed to decrypt: {e}")
```

### PDFs corrompidos
```bash
qpdf --check corrupted.pdf
qpdf --replace-input corrupted.pdf
```

### Falha na extraccao de texto (fallback para OCR)
```python
import pytesseract
from pdf2image import convert_from_path

def extract_text_with_ocr(pdf_path):
    images = convert_from_path(pdf_path)
    text = ""
    for i, image in enumerate(images):
        text += pytesseract.image_to_string(image)
    return text
```

## Dicas de performance

1. **PDFs grandes**: usar streaming em vez de carregar tudo em memoria; `qpdf --split-pages` para dividir
2. **Extraccao de texto**: `pdftotext -bbox-layout` e o mais rapido; pdfplumber para tabelas
3. **Extraccao de imagens**: `pdfimages` e muito mais rapido que rendering de paginas
4. **Preenchimento de formularios**: pdf-lib mantem melhor a estrutura do formulario
5. **Memoria**: processar paginas individualmente com pypdfium2 para documentos grandes

---

## Integracao Descomplicar

### Caminhos frequentes para PDFs

| Localizacao | Caminho |
|-------------|---------|
| Documentos empresa | `/media/ealmeida/Dados/GDrive/Cloud/Descomplicar/` |
| Propostas | `/media/ealmeida/Dados/Hub/03-Propostas/` |
| Arquivo clientes | `/media/ealmeida/Dados/GDrive/Arquivo_de_Clientes/` |
| Knowledge Base | `/media/ealmeida/Dados/Hub/06-Operacoes/Knowledge-Base/PDFs/` |
| Backups | `/media/ealmeida/Externo/LocalBackups/` (espelhado p/ GDrive via rclone) |
| Temporarios | `~/.claude-work/` (limpar ao concluir) |

### MCPs relevantes

- **mcp__filesystem__read_file** / **write_file**: ler e escrever PDFs locais
- **mcp__filesystem__search_files**: encontrar PDFs no sistema
- **mcp__google-workspace__drive_search_files**: encontrar PDFs no Google Drive
- **mcp__google-workspace__drive_read_file_content**: ler conteudo de ficheiros no Drive
- **mcp__google-workspace__drive_upload_file**: enviar PDFs processados para o Drive

### Workflow tipico Descomplicar

1. Localizar PDF (filesystem ou Google Drive)
2. Descarregar para `~/.claude-work/` se necessario
3. Processar (extrair, merge, split, OCR, etc.)
4. Guardar resultado no destino final
5. Limpar temporarios de `~/.claude-work/`

---

## Licencas das bibliotecas

- **pypdf**: BSD | **pdfplumber**: MIT | **pypdfium2**: Apache/BSD | **reportlab**: BSD
- **poppler-utils**: GPL-2 | **qpdf**: Apache | **pdf-lib**: MIT | **pdfjs-dist**: Apache

---
**Versao**: 1.0.0 | **Autor**: Descomplicar®

---

## Healing Log

Registo de erros conhecidos e como evitá-los. Lido automaticamente antes de executar.

```jsonl
{"date":"","issue":"","fix":"","source":"user|auto"}
```

*Adicionar nova linha após cada erro corrigido.*
