FEATURE: smart date support for AI helper

config/locales/server.en.yml

@@ -233,6 +233,7 @@ en:
         custom_prompt: "Custom Prompt"
         explain: "Explain"
         illustrate_post: "Illustrate Post"
+        replace_dates: "Smart Dates"
       painter:
         attribution:
           stable_diffusion_xl: "Image by Stable Diffusion XL"

db/fixtures/ai_helper/603_completion_prompts.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 # frozen_string_literal: true
 CompletionPrompt.seed do |cp|
   cp.id = -301
@@ -217,3 +215,55 @@
     examples: [["<input>Hello my favourite colour is red</input>", "<output>en-GB</output>"]],
   }
 end
+
+CompletionPrompt.seed do |cp|
+  cp.id = -310
+  cp.name = "replace_dates"
+  cp.prompt_type = CompletionPrompt.prompt_types[:diff]
+  cp.temperature = 0
+  cp.stop_sequences = ["\n</output>"]
+  cp.messages = {
+    insts: <<~TEXT,
+      You are a date and time formatter for Discourse posts. Convert natural language time references into date placeholders.
+      Do not modify any markdown, code blocks, or existing date formats.
+
+      Here's the temporal context:
+      {{temporal_context}}
+
+      Available date placeholder formats:
+      - Simple day without time: {{date:1}} for tomorrow, {{date:7}} for a week from today
+      - Specific time: {{datetime:2pm+1}} for 2 PM tomorrow
+      - Time range: {{datetime:2pm+1:4pm+1}} for tomorrow 2 PM to 4 PM
+
+      You will find the text between <input></input> XML tags.
+      Return the text with dates converted between <output></output> XML tags.
+    TEXT
+    examples: [
+      [
+        "<input>The meeting is at 2pm tomorrow</input>",
+        "<output>The meeting is at {{datetime:2pm+1}}</output>",
+      ],
+      ["<input>Due in 3 days</input>", "<output>Due {{date:3}}</output>"],
+      [
+        "<input>Meeting next Tuesday at 2pm</input>",
+        "<output>Meeting {{next_week:tuesday-2pm}}</output>",
+      ],
+      [
+        "<input>Meeting from 2pm to 4pm tomorrow</input>",
+        "<output>Meeting {{datetime:2pm+1:4pm+1}}</output>",
+      ],
+      [
+        "<input>Meeting notes for tomorrow:
+* Action items in `config.rb`
+* Review PR #1234
+* Deadline is 5pm
+* Check [this link](https://example.com)</input>",
+        "<output>Meeting notes for {{date:1}}:
+* Action items in `config.rb`
+* Review PR #1234
+* Deadline is {{datetime:5pm+1}}
+* Check [this link](https://example.com)</output>",
+      ],
+    ],
+  }
+end

lib/ai_helper/assistant.rb

@@ -89,6 +89,29 @@ def localize_prompt!(prompt, user = nil, force_default_locale)
             "#{locale_hash["name"]}",
           )
         end
+
+        if user && prompt.messages[0][:content].include?("{{temporal_context}}")
+          timezone = user.user_option.timezone || "UTC"
+          current_time = Time.now.in_time_zone(timezone)
+
+          temporal_context = {
+            utc_date_time: current_time.iso8601,
+            local_time: current_time.strftime("%H:%M"),
+            user: {
+              timezone: timezone,
+              weekday: current_time.strftime("%A"),
+            },
+          }
+
+          prompt.messages[0][:content] = prompt.messages[0][:content].gsub(
+            "{{temporal_context}}",
+            temporal_context.to_json,
+          )
+
+          prompt.messages.each do |message|
+            message[:content] = DateFormatter.process_date_placeholders(message[:content], user)
+          end
+        end
       end
 
       def generate_prompt(completion_prompt, input, user, force_default_locale = false, &block)
@@ -206,6 +229,8 @@ def icon_map(name)
           "question"
         when "illustrate_post"
           "images"
+        when "replace_dates"
+          "address-book"
         else
           nil
         end
@@ -233,6 +258,8 @@ def location_map(name)
           %w[post]
         when "illustrate_post"
           %w[composer]
+        when "replace_dates"
+          %w[composer]
         else
           %w[]
         end

lib/ai_helper/date_formatter.rb

@@ -0,0 +1,144 @@
+# frozen_string_literal: true
+
+module DiscourseAi
+  module AiHelper
+    class DateFormatter
+      DAYS_OF_WEEK = {
+        "monday" => 1,
+        "tuesday" => 2,
+        "wednesday" => 3,
+        "thursday" => 4,
+        "friday" => 5,
+        "saturday" => 6,
+        "sunday" => 0,
+      }
+
+      class << self
+        def process_date_placeholders(text, user)
+          return text if !text.include?("{{")
+
+          timezone = user.user_option.timezone || "UTC"
+          reference_time = Time.now.in_time_zone(timezone)
+
+          text.gsub(
+            /\{\{(date_time_offset_minutes|date_offset_days|datetime|date|next_week):([^}]+)\}\}/,
+          ) do |match|
+            type = $1
+            value = $2
+
+            case type
+            when "datetime"
+              if value.include?(":")
+                # Handle range like "2pm+1:3pm+2"
+                start_str, end_str = value.split(":")
+                format_datetime_range(
+                  parse_time_with_offset(start_str, reference_time),
+                  parse_time_with_offset(end_str, reference_time),
+                  timezone,
+                )
+              else
+                # Handle single time like "2pm+1" or "10pm"
+                format_date_time(parse_time_with_offset(value, reference_time), timezone)
+              end
+            when "next_week"
+              if value.include?(":")
+                # Handle range like "tuesday-1pm:tuesday-3pm"
+                start_str, end_str = value.split(":")
+                start_time = parse_next_week(start_str, reference_time)
+                end_time = parse_next_week(end_str, reference_time)
+                format_datetime_range(start_time, end_time, timezone)
+              else
+                # Handle single time like "tuesday-1pm" or just "tuesday"
+                time = parse_next_week(value, reference_time)
+                value.include?("-") ? format_date_time(time, timezone) : format_date(time, timezone)
+              end
+            when "date"
+              format_date(reference_time + value.to_i.days, timezone)
+            when "date_time_offset_minutes"
+              if value.include?(":")
+                start_offset, end_offset = value.split(":").map(&:to_i)
+                format_datetime_range(
+                  reference_time + start_offset.minutes,
+                  reference_time + end_offset.minutes,
+                  timezone,
+                )
+              else
+                format_date_time(reference_time + value.to_i.minutes, timezone)
+              end
+            when "date_offset_days"
+              if value.include?(":")
+                start_offset, end_offset = value.split(":").map(&:to_i)
+                format_date_range(
+                  reference_time + start_offset.days,
+                  reference_time + end_offset.days,
+                  timezone,
+                )
+              else
+                format_date(reference_time + value.to_i.days, timezone)
+              end
+            end
+          end
+        end
+
+        private
+
+        def parse_next_week(str, reference_time)
+          if str.include?("-")
+            # Handle day with time like "tuesday-1pm"
+            day, time = str.split("-")
+            target_date = get_next_week_day(day.downcase, reference_time)
+            parse_time(time, target_date)
+          else
+            # Just the day
+            get_next_week_day(str.downcase, reference_time)
+          end
+        end
+
+        def get_next_week_day(day, reference_time)
+          raise ArgumentError unless DAYS_OF_WEEK.key?(day)
+
+          target_date = reference_time + 1.week
+          days_ahead = DAYS_OF_WEEK[day] - target_date.wday
+          days_ahead += 7 if days_ahead < 0
+          target_date + days_ahead.days
+        end
+
+        def parse_time_with_offset(time_str, reference_time)
+          if time_str.include?("+")
+            time_part, days = time_str.split("+")
+            parse_time(time_part, reference_time + days.to_i.days)
+          else
+            parse_time(time_str, reference_time)
+          end
+        end
+
+        def parse_time(time_str, reference_time)
+          hour = time_str.to_i
+          if time_str.downcase.include?("pm") && hour != 12
+            hour += 12
+          elsif time_str.downcase.include?("am") && hour == 12
+            hour = 0
+          end
+
+          reference_time.change(hour: hour, min: 0, sec: 0)
+        end
+
+        def format_date(time, timezone)
+          "[date=#{time.strftime("%Y-%m-%d")} timezone=\"#{timezone}\"]"
+        end
+
+        def format_date_time(time, timezone)
+          "[date=#{time.strftime("%Y-%m-%d")} time=#{time.strftime("%H:%M:%S")} timezone=\"#{timezone}\"]"
+        end
+
+        def format_date_range(start_time, end_time, timezone)
+          "[date-range from=#{start_time.strftime("%Y-%m-%d")} to=#{end_time.strftime("%Y-%m-%d")} timezone=\"#{timezone}\"]"
+        end
+
+        def format_datetime_range(start_time, end_time, timezone)
+          "[date-range from=#{start_time.strftime("%Y-%m-%dT%H:%M:%S")} to=#{end_time.strftime("%Y-%m-%dT%H:%M:%S")} timezone=\"#{timezone}\"]"
+        end
+      end
+    end
+  end
+end

spec/lib/modules/ai_helper/assistant_spec.rb

@@ -48,7 +48,7 @@
     it "returns all available prompts" do
       prompts = subject.available_prompts(user)
 
-      expect(prompts.length).to eq(7)
+      expect(prompts.length).to eq(8)
       expect(prompts.map { |p| p[:name] }).to contain_exactly(
         "translate",
         "generate_titles",
@@ -57,19 +57,21 @@
         "custom_prompt",
         "explain",
         "detect_text_locale",
+        "replace_dates",
       )
     end
 
     it "returns all prompts to be shown in the composer" do
       prompts = subject.available_prompts(user)
       filtered_prompts = prompts.select { |prompt| prompt[:location].include?("composer") }
-      expect(filtered_prompts.length).to eq(5)
+      expect(filtered_prompts.length).to eq(6)
       expect(filtered_prompts.map { |p| p[:name] }).to contain_exactly(
         "translate",
         "generate_titles",
         "proofread",
         "markdown_table",
         "custom_prompt",
+        "replace_dates",
       )
     end
 
@@ -99,7 +101,7 @@
       it "returns the illustrate_post prompt in the list of all prompts" do
         prompts = subject.available_prompts(user)
 
-        expect(prompts.length).to eq(8)
+        expect(prompts.length).to eq(9)
         expect(prompts.map { |p| p[:name] }).to contain_exactly(
           "translate",
           "generate_titles",
@@ -109,6 +111,7 @@
           "explain",
           "illustrate_post",
           "detect_text_locale",
+          "replace_dates",
         )
       end
     end