From 0406e5cbf7defab9fbc8989bc48560af1350d14c Mon Sep 17 00:00:00 2001
From: Atridad Lahiji <me@atri.dad>
Date: Tue, 22 Oct 2024 00:01:19 -0600
Subject: [PATCH] Markov implementation

---
 command/markov.go | 111 ++++++++++++++++++++++++++++++++++++++++++++++
 main.go           |   9 +++-
 2 files changed, 118 insertions(+), 2 deletions(-)
 create mode 100644 command/markov.go

diff --git a/command/markov.go b/command/markov.go
new file mode 100644
index 0000000..8d3d6e4
--- /dev/null
+++ b/command/markov.go
@@ -0,0 +1,111 @@
+package command
+
+import (
+	"log"
+	"math/rand"
+	"strings"
+
+	"github.com/bwmarrin/discordgo"
+)
+
+// MarkovCommand generates a random message using Markov chains
+func MarkovCommand(s *discordgo.Session, i *discordgo.InteractionCreate) {
+	log.Println("MarkovCommand called")
+
+	// Get the channel ID from the interaction
+	channelID := i.ChannelID
+	log.Printf("Channel ID: %s", channelID)
+
+	// Fetch the last 100 messages from the channel
+	messages, err := s.ChannelMessages(channelID, 100, "", "", "")
+	if err != nil {
+		log.Printf("Error fetching messages: %v", err)
+		respondWithError(s, i, "Failed to fetch messages")
+		return
+	}
+	log.Printf("Fetched %d messages", len(messages))
+
+	// Build the Markov chain from the fetched messages
+	chain := buildMarkovChain(messages)
+	log.Printf("Built Markov chain with %d entries", len(chain))
+
+	// Generate a new message using the Markov chain
+	newMessage := generateMessage(chain)
+	log.Printf("Generated message: %s", newMessage)
+
+	// Check if the generated message is empty and provide a fallback message
+	if newMessage == "" {
+		newMessage = "I couldn't generate a message. The channel might be empty or contain no usable text."
+	}
+
+	// Respond to the interaction with the generated message
+	err = s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+		Type: discordgo.InteractionResponseChannelMessageWithSource,
+		Data: &discordgo.InteractionResponseData{
+			Content: newMessage,
+		},
+	})
+	if err != nil {
+		log.Printf("Error responding to interaction: %v", err)
+		return
+	}
+	log.Println("Successfully responded to interaction")
+}
+
+// buildMarkovChain creates a Markov chain from a list of messages
+func buildMarkovChain(messages []*discordgo.Message) map[string][]string {
+	chain := make(map[string][]string)
+	for _, msg := range messages {
+		words := strings.Fields(msg.Content)
+		log.Printf("Processing message: %s", msg.Content)
+		// Build the chain by associating each word with the word that follows it
+		for i := 0; i < len(words)-1; i++ {
+			chain[words[i]] = append(chain[words[i]], words[i+1])
+		}
+	}
+	log.Printf("Built chain with %d entries", len(chain))
+	return chain
+}
+
+// generateMessage creates a new message using the Markov chain
+func generateMessage(chain map[string][]string) string {
+	if len(chain) == 0 {
+		return ""
+	}
+
+	words := []string{}
+	var currentWord string
+
+	// Start with a random word from the chain
+	for word := range chain {
+		currentWord = word
+		break
+	}
+
+	// Generate up to 20 words
+	for i := 0; i < 20; i++ {
+		words = append(words, currentWord)
+		if nextWords, ok := chain[currentWord]; ok && len(nextWords) > 0 {
+			// Randomly select the next word from the possible follow-ups
+			currentWord = nextWords[rand.Intn(len(nextWords))]
+		} else {
+			break
+		}
+	}
+
+	return strings.Join(words, " ")
+}
+
+// respondWithError sends an error message as a response to the interaction
+func respondWithError(s *discordgo.Session, i *discordgo.InteractionCreate, message string) {
+	log.Printf("Responding with error: %s", message)
+	err := s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+		Type: discordgo.InteractionResponseChannelMessageWithSource,
+		Data: &discordgo.InteractionResponseData{
+			Content: message,
+		},
+	})
+	if err != nil {
+		log.Printf("Error sending error response: %v", err)
+	}
+}
diff --git a/main.go b/main.go
index b417d00..e60e47c 100644
--- a/main.go
+++ b/main.go
@@ -29,11 +29,16 @@ var (
 				},
 			},
 		},
+		{
+			Name:        "markov",
+			Description: "Testing markov chains.",
+		},
 	}
 
 	commandHandlers = map[string]func(s *discordgo.Session, i *discordgo.InteractionCreate){
-		"ping": command.PingCommand,
-		"hs":   command.HsCommand,
+		"ping":   command.PingCommand,
+		"hs":     command.HsCommand,
+		"markov": command.MarkovCommand,
 	}
 )