Run3 pdf calendar parsing

PDF Calendar Parsing

Inputs

• calendar_pdf_path: string, path to /root/calendar.pdf
• today_date: string, today's date in YYYY-MM-DD format (for context)

Outputs

• calendar_metadata: object containing:
  • timezone: string (e.g., "EST", "UTC", "PST")
  • dates_covered: list of dates in YYYY-MM-DD format shown on calendar
  • time_axis_range: {start_time, end_time} in HH:MM format
  • slot_duration_minutes: integer (typically 15)
• appointments: list of objects, each containing:
  • date: YYYY-MM-DD
  • start_time: HH:MM (24-hour format)
  • end_time: HH:MM (24-hour format)
  • title: string
  • color: string ("blue", "red", "green", etc.)
  • is_flexible: boolean (true if blue/flexible block)

Algorithm

1. Extract Calendar Metadata

• Use pdfplumber to load the PDF and inspect pages
• Search for timezone indicator in document text (look for patterns like "EST", "PST", "UTC", timezone label in header/footer)
• If timezone not found as text, default to "UTC" and flag as inferred
• Extract all text labels from calendar axes:
  • Time axis (vertical): Read all time labels (e.g., "9:00 AM", "9:15 AM") from left margin or axis; record pixel y-coordinates for each
  • Date axis (horizontal): Read all date/day labels from top/header; record pixel x-coordinates for each
• Build lookup tables: pixel_y → time and pixel_x → date
• Calculate slot_duration_minutes from difference between consecutive axis time labels divided by their pixel distance

2. Extract Calendar Dimensions & Gridlines

• Identify calendar grid bounds (top-left to bottom-right corners in pixels)
• Extract all horizontal and vertical lines from the PDF using pdfplumber's line extraction
• Filter to only lines within calendar bounds
• Record pixel positions of gridlines

3. Extract Appointments with Color Detection

• Use pdfplumber.objects to find all rectangles/shapes within calendar bounds
• For each rectangle, extract:
  • Position: x0, y0 (top-left), x1, y1 (bottom-right) in pixels
  • Color: Use fill or stroke RGB values from the rectangle object
    • If RGB values present, convert to color name:
      • Blue-ish (high B, low R/G): color = "blue", is_flexible = true
      • Red-ish (high R): color = "red", is_flexible = false
      • Other: extract as-is, assume is_flexible = false
    • If color data unavailable, check if rectangle has fill=None (outline only) vs. filled
• Map pixel coordinates to calendar time/date:
  • Use pixel_y → time lookup to get start_time and end_time
  • Use pixel_x → date lookup to get date
  • Round times to nearest slot_duration_minutes boundary
• Extract appointment title/label from text within or near the rectangle
• Store in appointments list

4. Validate and Return

• Ensure all appointments have valid start_time < end_time
• Ensure all dates are within dates_covered range
• Return structured metadata and appointments list