feat: editable calendar with rule-checked edits, undo and PDF export

README.md

@@ -43,6 +43,10 @@ The system is inspired by real-world healthcare scheduling challenges in 24/7 de
 - Interactive tables
 - Shift explanation viewer
 - Report export to `.txt`
+- Editable calendar (dates × day/evening/night) with staffing status per shift
+- Manual add, remove and replace of employees, checked by the scheduler's own rules
+- Undo of manual changes (button or Ctrl+Z) with a change history
+- PDF export of the current, possibly edited, schedule
 
 ### Assignment Transparency
 
@@ -57,16 +61,31 @@ The system explains WHY employees were assigned:
 
 # Screenshots
 
-## Main GUI
+## Editable calendar
 
-_Add screenshot here later_
+A change that breaks a scheduling rule is refused with every reason (here Jonas is at capacity and would get too little rest after an evening shift):
+
+![Refused change in the calendar](docs/images/calendar-rule-refused.png)
+
+After replacing Jonas with Peter on Sunday evening, Jonas can take Monday's open UL shift. The history lists both changes:
+
+![Edited calendar with change history](docs/images/calendar-edited.png)
+
+Undo (button or Ctrl+Z) reverts the latest change exactly:
+
+![Calendar after undo](docs/images/calendar-undo.png)
+
+## PDF export
+
+![First page of the exported PDF](docs/images/pdf-export.png)
 
 ---
 
 ## Technologies
 
 - Python 3.12
 - Tkinter
+- ReportLab (PDF export)
 - Pytest
 - CSV-based data import
 
@@ -79,6 +98,9 @@ python-shift-planner-desktop/
 │
 ├── app/
 │   ├── gui.py
+│   ├── calendar_view.py
+│   ├── schedule_editor.py
+│   ├── pdf_export.py
 │   ├── main.py
 │   ├── scheduler.py
 │   ├── models.py
@@ -138,6 +160,20 @@ Run tests:
 pytest
 ```
 
+## Editing the schedule
+
+1. Click **Kør vagtplan** to generate the schedule from the CSV files.
+2. Open the **Kalender** tab and click a shift. Green shifts are fully staffed, red shifts miss people, blue is selected.
+3. Choose an employee and click **Tilføj**, select someone on the shift and click **Fjern valgte**, or select both and click **Erstat valgte**. The list shows every employee; those who cannot take the shift show why.
+4. Every change is checked with the same rules as the scheduler: required skill, maximum number of shifts, one shift per day, and rest time (no shift the day after a night, no day shift after an evening). A refused change shows all reasons and changes nothing.
+5. **Fortryd (Ctrl+Z)** reverts the latest change. The other tabs (assigned, unassigned, risk, explanations) update after every change.
+
+Changes live in memory only: **the CSV files are never written**. Clicking **Kør vagtplan** again rebuilds the plan from the CSV files and asks first if there are manual changes.
+
+## PDF export
+
+**Eksportér PDF** saves the current schedule: period, print time, number of manual changes, every shift with its staff (shifts missing people are highlighted) and each employee's shifts and workload. The save dialog asks before replacing an existing file. The PDF is written to a temporary file first and then moved into place, so a failed export never damages an existing file.
+
 ---
 
 # CSV Data Format
@@ -177,18 +213,20 @@ employee_id,name,night_tolerance,weekend_tolerance,late_tolerance,max_weekly_loa
 - GUI reporting
 - Report export
 - Interactive explanations
+- Editable calendar with rule-checked manual changes
+- Undo of manual changes
+- PDF export
 
 ---
 
 # Planned Features
 
 - SQLite database
 - Drag-and-drop scheduling
-- Calendar view
+- Saving an edited schedule (today edits are kept in memory and exported as PDF)
 - Fairness optimization
 - AI-assisted scheduling
 - What-if simulations
-- PDF export
 - Employee preference management
 - Real-world agreement rules
 
@@ -205,6 +243,11 @@ Current coverage includes:
 - CSV loading
 - Personalized workload scoring
 - Scheduler behavior
+- Schedule editing: add, remove and replace through the scheduler's rules, refused changes leaving the schedule untouched, and undo restoring the exact earlier state (including order)
+- Calendar grouping by date and shift type
+- PDF export: content, no overwrite without permission, an existing file kept when an export fails, and input CSV files unchanged after editing and exporting
+
+The GUI itself (`calendar_view.py`, `gui.py`) is not covered by automated tests; its rules and state live in `schedule_editor.py`, which is. See [docs/PROJECT_WALKTHROUGH.md](docs/PROJECT_WALKTHROUGH.md) for the desktop demonstration.
 
 ---
 

app/calendar_view.py

@@ -0,0 +1,280 @@
+"""The editable calendar tab: a date × shift type grid and a panel for changing one shift."""
+
+import tkinter as tk
+from collections.abc import Callable
+from datetime import date
+from tkinter import ttk
+
+from app.models import Shift
+from app.schedule_editor import ScheduleEditError, ScheduleEditor, build_calendar, describe_blocker, describe_shift
+
+WEEKDAYS = ["Man", "Tir", "Ons", "Tor", "Fre", "Lør", "Søn"]
+
+STAFFED_COLOUR = "#d1fae5"
+MISSING_COLOUR = "#fee2e2"
+SELECTED_COLOUR = "#bfdbfe"
+OK_TEXT_COLOUR = "#065f46"
+ERROR_TEXT_COLOUR = "#991b1b"
+
+
+class CalendarView(ttk.Frame):
+    def __init__(self, parent, on_change: Callable[[], None]):
+        super().__init__(parent)
+        self.on_change = on_change
+        self.editor: ScheduleEditor | None = None
+        self.selected_shift: Shift | None = None
+        self.shift_buttons: dict[int, tk.Button] = {}
+        self.candidate_employees = []
+
+        # The panel is packed first so it keeps its width; the calendar gets the rest and scrolls.
+        self._create_edit_panel()
+        self._create_scrollable_grid_area()
+        tk.Label(self.grid_area, text="Kør vagtplanen for at se kalenderen.").pack(pady=20)
+
+    def _create_scrollable_grid_area(self) -> None:
+        container = tk.Frame(self)
+        container.pack(side=tk.LEFT, fill="both", expand=True, padx=(10, 4), pady=6)
+
+        history = tk.LabelFrame(container, text="Ændringer (nyeste først) – fortryd med Ctrl+Z", padx=6, pady=4)
+        history.pack(side=tk.BOTTOM, fill="x", pady=(6, 0))
+        self.history_list = tk.Listbox(history, height=3)
+        self.history_list.pack(fill="x")
+
+        canvas = tk.Canvas(container, highlightthickness=0)
+        horizontal = ttk.Scrollbar(container, orient="horizontal", command=canvas.xview)
+        vertical = ttk.Scrollbar(container, orient="vertical", command=canvas.yview)
+        canvas.configure(xscrollcommand=horizontal.set, yscrollcommand=vertical.set)
+
+        horizontal.pack(side=tk.BOTTOM, fill="x")
+        vertical.pack(side=tk.RIGHT, fill="y")
+        canvas.pack(side=tk.LEFT, fill="both", expand=True)
+
+        self.grid_area = tk.Frame(canvas)
+        canvas.create_window((0, 0), window=self.grid_area, anchor="nw")
+        self.grid_area.bind(
+            "<Configure>",
+            lambda event: canvas.configure(scrollregion=canvas.bbox("all")),
+        )
+
+    def _create_edit_panel(self) -> None:
+        panel = tk.LabelFrame(self, text="Redigér vagt", padx=8, pady=6)
+        panel.pack(side=tk.RIGHT, fill="y", padx=(4, 10), pady=6)
+
+        self.shift_label = tk.Label(panel, text="Vælg en vagt i kalenderen.", font=("Arial", 10, "bold"),
+                                    wraplength=250, justify="left")
+        self.shift_label.pack(anchor="w")
+
+        # Directly under the heading so the result of a change is always visible.
+        self.message = tk.Label(panel, text="", wraplength=250, justify="left")
+        self.message.pack(anchor="w", pady=(6, 0))
+
+        tk.Label(panel, text="På vagten:").pack(anchor="w", pady=(8, 0))
+        self.assigned_list = tk.Listbox(panel, height=2, exportselection=False)
+        self.assigned_list.pack(fill="x")
+
+        self.remove_button = tk.Button(panel, text="Fjern valgte", command=self.remove_selected, state=tk.DISABLED)
+        self.remove_button.pack(anchor="w", pady=4)
+
+        tk.Label(panel, text="Medarbejder:").pack(anchor="w", pady=(10, 0))
+        self.candidate_box = ttk.Combobox(panel, state="readonly", width=34)
+        self.candidate_box.pack(fill="x")
+
+        buttons = tk.Frame(panel)
+        buttons.pack(anchor="w", pady=4)
+        self.add_button = tk.Button(buttons, text="Tilføj", command=self.add_selected, state=tk.DISABLED)
+        self.add_button.pack(side=tk.LEFT)
+        self.replace_button = tk.Button(buttons, text="Erstat valgte", command=self.replace_selected,
+                                        state=tk.DISABLED)
+        self.replace_button.pack(side=tk.LEFT, padx=6)
+
+
+    def load(self, editor: ScheduleEditor) -> None:
+        self.editor = editor
+        self.selected_shift = None
+        self.show_message("")
+        self.refresh()
+
+    def clear(self) -> None:
+        self.editor = None
+        self.selected_shift = None
+        self.show_message("")
+        self.refresh()
+
+    def refresh(self) -> None:
+        self._draw_grid()
+        self._update_panel()
+
+    def _draw_grid(self) -> None:
+        for child in self.grid_area.winfo_children():
+            child.destroy()
+
+        self.shift_buttons = {}
+
+        if self.editor is None or not self.editor.shifts:
+            tk.Label(self.grid_area, text="Kør vagtplanen for at se kalenderen.").pack(pady=20)
+            return
+
+        dates, shift_types, cells = build_calendar(self.editor.shifts)
+        table = tk.Frame(self.grid_area)
+        table.pack(anchor="nw")
+
+        for column, day in enumerate(dates, start=1):
+            weekday = WEEKDAYS[date.fromisoformat(day).weekday()]
+            tk.Label(table, text=f"{weekday}\n{day}", font=("Arial", 9, "bold")).grid(row=0, column=column, padx=2)
+
+        for row, shift_type in enumerate(shift_types, start=1):
+            tk.Label(table, text=shift_type.display_name, font=("Arial", 9, "bold")).grid(row=row, column=0, sticky="e",
+                                                                                            padx=4)
+
+            for column, day in enumerate(dates, start=1):
+                cell_frame = tk.Frame(table, bd=1, relief="solid", width=130, height=70)
+                cell_frame.grid(row=row, column=column, padx=2, pady=2, sticky="nsew")
+                cell = cells.get((day, shift_type))
+
+                if cell is None:
+                    tk.Label(cell_frame, text="–", fg="#9ca3af", width=12).pack(pady=8)
+                    continue
+
+                for shift in cell.shifts:
+                    self._add_shift_button(cell_frame, shift)
+
+    def _add_shift_button(self, parent: tk.Frame, shift: Shift) -> None:
+        names = ", ".join(employee.name for employee in shift.assigned_employees) or "Ingen"
+        staffing = f"{len(shift.assigned_employees)}/{shift.required_staff}"
+
+        button = tk.Button(
+            parent,
+            text=f"{shift.required_skill} {staffing}\n{names}",
+            width=12,
+            wraplength=100,
+            justify="center",
+            relief="flat",
+            bg=self._colour(shift),
+            command=lambda: self.select_shift(shift),
+        )
+        button.pack(fill="x", padx=2, pady=2)
+        self.shift_buttons[id(shift)] = button
+
+    def _colour(self, shift: Shift) -> str:
+        if shift is self.selected_shift:
+            return SELECTED_COLOUR
+
+        return STAFFED_COLOUR if shift.is_fully_staffed else MISSING_COLOUR
+
+    def select_shift(self, shift: Shift) -> None:
+        self.selected_shift = shift
+        self.show_message("")
+
+        for button_shift in self.editor.shifts:
+            button = self.shift_buttons.get(id(button_shift))
+            if button is not None:
+                button.configure(bg=self._colour(button_shift))
+
+        self._update_panel()
+
+    def _update_panel(self) -> None:
+        self.assigned_list.delete(0, tk.END)
+        self.history_list.delete(0, tk.END)
+        self.candidate_box.set("")
+
+        if self.editor is not None:
+            for description in self.editor.history:
+                self.history_list.insert(tk.END, description)
+
+        shift = self.selected_shift
+
+        if self.editor is None or shift is None:
+            self.shift_label.configure(text="Vælg en vagt i kalenderen.")
+            self.candidate_box.configure(values=[])
+            for button in (self.remove_button, self.add_button, self.replace_button):
+                button.configure(state=tk.DISABLED)
+            return
+
+        self.shift_label.configure(
+            text=f"{describe_shift(shift)}\nBemanding {len(shift.assigned_employees)}/{shift.required_staff}, "
+                 f"prioritet {shift.priority}"
+        )
+
+        for employee in shift.assigned_employees:
+            self.assigned_list.insert(tk.END, employee.name)
+
+        candidates = self.editor.candidates(shift)
+        self.candidate_employees = [employee for employee, _ in candidates]
+        self.candidate_box.configure(
+            values=[
+                employee.name if not blockers
+                else f"{employee.name} – {', '.join(describe_blocker(blocker) for blocker in blockers)}"
+                for employee, blockers in candidates
+            ]
+        )
+
+        has_people = bool(shift.assigned_employees)
+        self.remove_button.configure(state=tk.NORMAL if has_people else tk.DISABLED)
+        self.replace_button.configure(state=tk.NORMAL if has_people and candidates else tk.DISABLED)
+        self.add_button.configure(state=tk.NORMAL if candidates else tk.DISABLED)
+
+    def _chosen_candidate(self):
+        index = self.candidate_box.current()
+
+        if index < 0:
+            self.show_message("Vælg en medarbejder først.", error=True)
+            return None
+
+        return self.candidate_employees[index]
+
+    def _chosen_assigned(self):
+        selection = self.assigned_list.curselection()
+
+        if not selection:
+            self.show_message("Vælg en medarbejder på vagten først.", error=True)
+            return None
+
+        return self.selected_shift.assigned_employees[selection[0]]
+
+    def add_selected(self) -> None:
+        employee = self._chosen_candidate()
+
+        if employee is not None:
+            self._apply(lambda: self.editor.assign(self.selected_shift, employee), employee.name)
+
+    def remove_selected(self) -> None:
+        employee = self._chosen_assigned()
+
+        if employee is not None:
+            self._apply(lambda: self.editor.unassign(self.selected_shift, employee), employee.name)
+
+    def replace_selected(self) -> None:
+        current = self._chosen_assigned()
+        replacement = self._chosen_candidate() if current is not None else None
+
+        if current is not None and replacement is not None:
+            self._apply(lambda: self.editor.replace(self.selected_shift, current, replacement), replacement.name)
+
+    def undo(self) -> None:
+        if self.editor is None:
+            return
+
+        edit = self.editor.undo()
+
+        if edit is None:
+            self.show_message("Der er intet at fortryde.", error=True)
+            return
+
+        self.refresh()
+        self.show_message(f"Fortrudt: {edit.description}")
+        self.on_change()
+
+    def _apply(self, change: Callable, employee_name: str) -> None:
+        try:
+            edit = change()
+        except ScheduleEditError as error:
+            reasons = ", ".join(describe_blocker(reason) for reason in error.reasons)
+            self.show_message(f"Ikke tilladt for {employee_name}: {reasons}.", error=True)
+            return
+
+        self.refresh()
+        self.show_message(edit.description)
+        self.on_change()
+
+    def show_message(self, text: str, error: bool = False) -> None:
+        self.message.configure(text=text, fg=ERROR_TEXT_COLOUR if error else OK_TEXT_COLOUR)