# WHODIDIT: OpenStreetMap Changeset Analyzer

This tool downloads replication diffs from OSM Planet site, calculates statistics on changes
and registers which 0.01-degree tiles were affected, and stores this in a MySQL database.
A series of PHP scripts and a JS frontend are used to access that data.

You can check a working installation at https://simon04.dev.openstreetmap.org/whodidit/

## Installation

Install Go.

```sh
cd parse_osc/
go build
ls parse_osc
```

Create database tables, see `ddl.sql`.

Install systemd.

```sh
mkdir -p $HOME/.config/systemd/user/
cp systemd/parse_osc.* $HOME/.config/systemd/user/
systemctl --user daemon-reload
systemctl --user enable --now parse_osc.timer
systemctl --user list-timers
```

Now each minute your database will be updated with fresh data. Note that the same osmChange
file **should not** be processed twice: the database has no means of skipping already
processed files.

### Frontend

Make a directory inside www root, for example, `/var/www/whodidit`. Put all files
from `www` directory in it. Then create another directory, `/var/www/whodidit/scripts`
and put there all four PHP scripts from `scripts`.

Update the line `<script>var scripts = 'http://localhost/wdi/scripts/';</script>` in `index.html`
with the absolute URL of the directory you've put PHP files in. Then edit
`db.inc.php` script, updating `$frontend_url` variable with the absolute path to `index.html`.

Then write your database parameters into `connect()` function in `db.inc.php`, and you're set.

## What do scripts do?

* `parse_osc.pl`: This script downloads and parses replication diffs, storing changeset information
    in a MySQL database. It can create tables (with `-c` switch). Run it without parameters
    to see a list of all possible options.
* `db.inc.php`: Global settings for PHP scripts, also two useful functions (which can be updated
    in later versions, so be careful not to lose your settings -- sorry).
* `tiles.php`: Queries the database for tiles in an area. Returns JSON with either error message
    (large areas and areas that have more than 1000 tiles are rejected) or all tiles with changeset
    numbers and other information.
* `changeset.php`: Returns a JSON with detailed information for requested changeset ids. When
    called with `latest=1` parameter, returns the latest changeset.
* `rss.php`: As the title suggests, it generated an RSS feed with the latest changesets in a bbox.
* `index.html`: The HTML page is a front-end to WDI infrastructure. It makes use of all PHP scripts
    and allows user to check WDI tiles and aquire RSS links.
* `whodidit.js`: The JavaScript behind the front-end.

## Author

The tool has been created by Ilya Zverev, licensed WTFPL, and has been modified/extended by Simon Legner.
See https://github.com/simon04/whodidit/graphs/contributors for the full and detailed list of contributors.
It internally uses OpenLayers, licensed BSD.