Mod portal: change "download count" to "install count"

[jonatkins]

The mod portal keeps track of download count for mods, and allows sorting mods in search by this count. It seems the main intent of this is to highlight popular mods, but download count is a poor indication of this.

• Mods with frequent updates get a high download count, as users update from one version to the next
• Mods with seem good from the title/description, but are soon removed, are just as prominant as a mod that gets few updates.

A far better indication of mod popularity would be "install count". To track this, the mod portal would need to

• Track 'mod update checks' from the game on a per-player basis
• Keep in mind players might have multiple Factorio installs, with different mods in each. Easiest option is probably to count a mod as installed for a player if they've performed a version update check for it within the last week - but more complex options are possible if each install of a user sends a unique ID to the server.
• The current manual update check for mods isn't ideal - better would be automatic mod update checks performed at the same time as factorio version update checks.

Of course, automatic mod update checks should be an option - just like game version checks are. Also, some players might want a "don't track installed mods" option - e.g. players who have a factorio install for frequent mod experimentation.

However, these suggested client changes are all optional nice-to-have improvements - the core switch in the mod portal from download count to install count should be possible in the existing framework (assuming, that is, client checks for mod updates include the player username)

[Oktokolo]

A less storage-intensive solution could be to not count manual downloads and only count ingame downloads where the mod did not have been installed before. The game could remember mods that where installed at any time in its installation lifetime and send a flag alongside the download request indicating whether it downloads the mod for the first time.
This method would not be perfectly accurate (manual downloads are never counted and the first download from inside a fresh Factorio installation would always be counted as first-time downloads).
But it should be accurate enough as a popularity metric.

[MostlyNumbers]

I agree, this would be a cool update.
Bonus points if we can get sort of "currently enabled" vs "ever installed" counts, but that may be asking too much.