Add Wikidata climate attributes and integration to gardens (#4627)

* Add Wikidata integration for garden climate data

- Add location_wikidata_id, lowest_temp_c, and highest_temp_c to gardens.
- Implement WikidataService for fetching IDs and temperature properties.
- Map P6591 to highest_temp_c and P7422 to lowest_temp_c with unit conversion.
- Automatically populate Wikidata info on garden location change.
- Add manual "Fetch Wikidata info" button and opt-in prompt to garden show page.
- Update gardens_controller to permit new attributes and handle manual fetch.
- Update db/schema.rb manually to include new columns and migration version.

Co-authored-by: CloCkWeRX <365751+CloCkWeRX@users.noreply.github.com>

* Fix migration

* Improve display

---------

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

app/controllers/gardens_controller.rb

@@ -57,12 +57,23 @@ class GardensController < DataController
     redirect_to(member_gardens_path(@garden.owner))
   end
 
+  def fetch_wikidata
+    if @garden.populate_wikidata_info
+      @garden.save
+      flash[:notice] = "Wikidata information updated."
+    else
+      flash[:alert] = "Could not find Wikidata information for this location."
+    end
+    redirect_to @garden
+  end
+
   private
 
   def garden_params
     params.require(:garden).permit(
       :name, :slug, :description, :active,
-      :location, :latitude, :longitude, :area, :area_unit, :garden_type_id
+      :location, :latitude, :longitude, :area, :area_unit, :garden_type_id,
+      :location_wikidata_id, :lowest_temp_c, :highest_temp_c
     )
   end
 end

app/models/garden.rb

@@ -21,6 +21,7 @@ class Garden < ApplicationRecord
   after_validation :cleanup_area
   after_validation :geocode
   after_validation :empty_unwanted_geocodes
+  after_validation :populate_wikidata_info, if: :will_save_change_to_location?
   after_save :mark_inactive_garden_plantings_as_finished
 
   scope :active, -> { where(active: true) }
@@ -92,6 +93,19 @@ class Garden < ApplicationRecord
     end
   end
 
+  def populate_wikidata_info
+    return false if location.blank?
+
+    wd_id = WikidataService.find_wikidata_id(location)
+    return false if wd_id.blank?
+
+    self.location_wikidata_id = wd_id
+    temps = WikidataService.fetch_temps(wd_id)
+    self.highest_temp_c = temps[:highest_temp_c]
+    self.lowest_temp_c = temps[:lowest_temp_c]
+    true
+  end
+
   protected
 
   def strip_blanks

app/services/wikidata_service.rb

@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+require 'net/http'
+require 'json'
+
+class WikidataService
+  CELSIUS_UNIT_ID = 'http://www.wikidata.org/entity/Q25267'
+  FAHRENHEIT_UNIT_ID = 'http://www.wikidata.org/entity/Q42289'
+
+  def self.find_wikidata_id(location_name)
+    return nil if location_name.blank?
+
+    uri = URI("https://www.wikidata.org/w/api.php?action=wbsearchentities&search=#{URI.encode_www_form_component(location_name)}&language=en&format=json")
+    req = Net::HTTP::Get.new(uri)
+    req['User-Agent'] = "Growstuff (https://www.growstuff.org; admin@growstuff.org)"
+
+    response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) do |http|
+      http.request(req)
+    end
+
+    data = JSON.parse(response.body)
+    data.dig('search', 0, 'id')
+  rescue StandardError => e
+    Rails.logger.error "WikidataService.find_wikidata_id error: #{e.message}"
+    nil
+  end
+
+  def self.fetch_temps(wikidata_id)
+    return {} if wikidata_id.blank?
+
+    uri = URI("https://www.wikidata.org/w/api.php?action=wbgetentities&ids=#{wikidata_id}&props=claims&format=json")
+    req = Net::HTTP::Get.new(uri)
+    req['User-Agent'] = "Growstuff (https://www.growstuff.org; admin@growstuff.org)"
+
+    response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) do |http|
+      http.request(req)
+    end
+
+    data = JSON.parse(response.body)
+    claims = data.dig('entities', wikidata_id, 'claims') || {}
+
+    highest_temp = extract_temp(claims['P6591'])
+    lowest_temp = extract_temp(claims['P7422'])
+
+    {
+      highest_temp_c: highest_temp,
+      lowest_temp_c: lowest_temp
+    }
+  rescue StandardError => e
+    Rails.logger.error "WikidataService.fetch_temps error: #{e.message}"
+    {}
+  end
+
+  def self.extract_temp(claim_data)
+    return nil if claim_data.blank?
+
+    # We take the first value
+    main_snak = claim_data.first&.dig('mainsnak')
+    return nil unless main_snak&.dig('datavalue', 'type') == 'quantity'
+
+    quantity_data = main_snak.dig('datavalue', 'value')
+    amount = quantity_data['amount'].to_f
+    unit = quantity_data['unit']
+
+    case unit
+    when CELSIUS_UNIT_ID
+      amount
+    when FAHRENHEIT_UNIT_ID
+      (amount - 32) * 5.0 / 9.0
+    else
+      nil
+    end
+  end
+end

app/views/gardens/show.html.haml

@@ -124,6 +124,31 @@
             %strong Garden type:
             = @garden.garden_type.name
 
+        - if @garden.location_wikidata_id.present?
+          %hr
+          %p
+            %small
+              Data about this location from 
+              = link_to "wikidata", "https://www.wikidata.org/wiki/#{@garden.location_wikidata_id}", target: '_blank', rel: 'noopener noreferrer'
+
+          %p
+            %strong Highest temperature:
+            - if @garden.highest_temp_c.present?
+              = "#{ @garden.highest_temp_c.round(1) }°C"
+            - else
+              Not known
+          %p
+            %strong Lowest temperature:
+            - if @garden.lowest_temp_c.present?
+              = "#{ @garden.lowest_temp_c.round(1) }°C"
+            - else
+              Not known
+
+        - elsif can?(:edit, @garden) && @garden.location.present?
+          .alert.alert-info
+            %p Wikidata information is missing for this location.
+            = button_to "Fetch Wikidata info", fetch_wikidata_garden_path(@garden), method: :post, class: 'btn btn-info btn-sm'
+
     .card
       .card-header
         %h4 #{@garden.owner}'s gardens

config/routes.rb

@@ -32,6 +32,7 @@ Rails.application.routes.draw do
 
   resources :gardens, concerns: :has_photos, param: :slug do
     get 'timeline' => 'charts/gardens#timeline', constraints: { format: 'json' }
+    post 'fetch_wikidata' => 'gardens#fetch_wikidata', on: :member
 
     resources :garden_collaborators
   end

db/migrate/20250511035341_add_wikidata_and_temps_to_gardens.rb

@@ -0,0 +1,7 @@
+class AddWikidataAndTempsToGardens < ActiveRecord::Migration[7.2]
+  def change
+    add_column :gardens, :location_wikidata_id, :string
+    add_column :gardens, :lowest_temp_c, :float
+    add_column :gardens, :highest_temp_c, :float
+  end
+end

db/schema.rb

@@ -631,6 +631,9 @@ ActiveRecord::Schema[7.2].define(version: 2026_04_29_132911) do
     t.decimal "area"
     t.string "area_unit"
     t.integer "garden_type_id"
+    t.string "location_wikidata_id"
+    t.float "lowest_temp_c"
+    t.float "highest_temp_c"
     t.index ["garden_type_id"], name: "index_gardens_on_garden_type_id"
     t.index ["owner_id"], name: "index_gardens_on_owner_id"
     t.index ["slug"], name: "index_gardens_on_slug", unique: true