gochat/backend/internal/model/copilot_models.go

package model

import (
	"encoding/json"
	"fmt"

	"gorm.io/gorm"
)

// --- Copilot Thread Model ---
// Reference: Chatwoot enterprise/app/models/copilot_thread.rb
// Table: copilot_threads
//
// CopilotThread represents a conversation thread between a user
// and a Captain Assistant in the Copilot UI (side-panel chat).
// Linked to Account, User, and optionally an Assistant.

type CopilotThread struct {
	Base
	AccountID   uint   `gorm:"index;not null" json:"account_id"`
	UserID      uint   `gorm:"index;not null" json:"user_id"`
	AssistantID *uint  `gorm:"index" json:"assistant_id,omitempty"`
	Title       string `gorm:"size:255;not null" json:"title"`

	// Relationships
	Messages  []CopilotMessage `gorm:"foreignKey:CopilotThreadID" json:"messages,omitempty"`
	User      User             `gorm:"foreignKey:UserID" json:"user,omitempty"`
	Assistant CaptainAssistant `gorm:"foreignKey:AssistantID" json:"assistant,omitempty"`
}

func (CopilotThread) TableName() string { return "copilot_threads" }

// PreviousHistory returns the conversation history as role/content pairs
// for LLM context building. Reference: Chatwoot CopilotThread#previous_history
func (t *CopilotThread) PreviousHistory(messages []CopilotMessage) []ChatMessage {
	var history []ChatMessage
	for _, m := range messages {
		if m.MessageType == CopilotMessageTypeUser || m.MessageType == CopilotMessageTypeAssistant {
			content := m.GetMessageContent()
			history = append(history, ChatMessage{
				Role:    string(m.MessageType),
				Content: content,
			})
		}
	}
	return history
}

// --- Copilot Message Model ---
// Reference: Chatwoot enterprise/app/models/copilot_message.rb
// Table: copilot_messages
//
// CopilotMessage represents a single message within a CopilotThread.
// Message content is stored as JSONB (supports structured content,
// tool results, thinking traces). MessageType: user/assistant/assistant_thinking.

type CopilotMessage struct {
	Base
	AccountID       uint               `gorm:"index;not null" json:"account_id"`
	CopilotThreadID uint               `gorm:"index;not null" json:"copilot_thread_id"`
	MessageType     CopilotMessageType `gorm:"size:50;default:user;not null" json:"message_type"`
	Message         json.RawMessage    `gorm:"type:jsonb;not null" json:"message"`
	CopilotThread   CopilotThread      `gorm:"foreignKey:CopilotThreadID" json:"copilot_thread,omitempty"`
}

func (CopilotMessage) TableName() string { return "copilot_messages" }

// BeforeSave mirrors Chatwoot's CopilotMessage JSON key validation so
// reloadable tool-call state stays compatible with the reused frontend.
func (m *CopilotMessage) BeforeSave(tx *gorm.DB) error {
	if len(m.Message) == 0 {
		return nil
	}
	var msgMap map[string]interface{}
	if err := json.Unmarshal(m.Message, &msgMap); err != nil {
		return err
	}
	allowed := map[string]bool{
		"content":          true,
		"reasoning":        true,
		"function_name":    true,
		"reply_suggestion": true,
	}
	for key := range msgMap {
		if !allowed[key] {
			return fmt.Errorf("message contains invalid attribute: %s", key)
		}
	}
	return nil
}

// GetMessageContent extracts the "content" field from the JSONB message.
func (m *CopilotMessage) GetMessageContent() string {
	var msgMap map[string]interface{}
	if err := json.Unmarshal(m.Message, &msgMap); err != nil {
		return ""
	}
	if val, ok := msgMap["content"]; ok {
		s, _ := val.(string)
		return s
	}
	return ""
}

// CopilotSuggestionMessage represents a Copilot suggestion/reply tied to a conversation.
// These are "side-panel" suggestions the Copilot generates for the agent,
// distinct from the thread-based CopilotMessage (which tracks the full chat history).
// Reference: Chatwoot enterprise/app/controllers/api/v1/copilot_messages_controller.rb
// Table: copilot_suggestion_messages
type CopilotSuggestionType string

const (
	CopilotSuggestionTypeReply      CopilotSuggestionType = "reply"
	CopilotSuggestionTypeSuggestion CopilotSuggestionType = "suggestion"
	CopilotSuggestionTypeSummary    CopilotSuggestionType = "summary"
)

type CopilotSuggestionStatus string

const (
	CopilotSuggestionStatusPending  CopilotSuggestionStatus = "pending"
	CopilotSuggestionStatusAccepted CopilotSuggestionStatus = "accepted"
	CopilotSuggestionStatusRejected CopilotSuggestionStatus = "rejected"
)

type CopilotSuggestionMessage struct {
	Base
	AccountID      uint                    `gorm:"index;not null" json:"account_id"`
	ConversationID uint                    `gorm:"index;not null" json:"conversation_id"`
	Content        string                  `gorm:"type:text;not null" json:"content"`
	SuggestionType CopilotSuggestionType   `gorm:"size:50;not null;default:suggestion" json:"suggestion_type"`
	Status         CopilotSuggestionStatus `gorm:"size:50;not null;default:pending" json:"status"`
}

func (CopilotSuggestionMessage) TableName() string { return "copilot_suggestion_messages" }

// ChatMessage is a simplified LLM message format (role + content).
// Used for building LLM conversation context.
type ChatMessage struct {
	Role    string `json:"role"`
	Content string `json:"content"`
}