# Calendar-Vim Integration Use Case Specification

## Overview
This document describes how nuwiki (vimwiki) integrates with calendar-vim to provide graphical calendar navigation for wiki diary entries.

## Integration Mechanism
Nuwiki activates the integration by setting calendar-vim's hook variables when `g:vimwiki_use_calendar` is enabled (default: true):
- `g:calendar_action = 'vimwiki#diary#calendar_action'`
- `g:calendar_sign = 'vimwiki#diary#calendar_sign'`

## Primary Use Case: Viewing/Create Diary Entries
1. User executes `:Calendar` command
2. Calendar-vim displays navigable calendar interface
3. User navigates to target date using arrow keys
4. User presses `<Enter>` on selected date
5. `vimwiki#diary#calendar_action` function executes:
   - Formats date as YYYY-MM-DD
   - Opens existing diary file or creates new one
   - Applies appropriate wiki filetype
   - Sets up autocmd to refresh calendar on file close
6. User views/edits diary entry for selected date

## Date Marking Functionality
- `vimwiki#diary#calendar_sign` function determines which dates show markers (*)
- Returns true if diary file exists for that date using wiki's path configuration
- Provides visual indication of dates with existing diary entries

## Key Features
- Seamless navigation between calendar and diary entries
- Automatic file creation/opening for selected dates
- Visual indicators for dates with existing content
- Proper window splitting based on calendar orientation
- Automatic calendar refresh after editing diary entries

## Configuration
Controlled by:
- `g:vimwiki_use_calendar` (global toggle)
- Individual wiki configurations in `g:vimwiki_list` (path, diary_rel_path, ext)
- Standard calendar-vim variables for appearance/customization

This integration leverages calendar-vim's strong date presentation while using nuwiki's diary system for file management, creating a cohesive experience for journal-style wiki usage.