package api

import (
	"database/sql"
	"database/sql/driver"
	"encoding/json"
	"time"
)

type Conversation struct {
	ID             uint `gorm:"primaryKey"`
	ShortName      sql.NullString
	Title          string
	SelectedRootID *uint
	SelectedRoot   *Message `gorm:"foreignKey:SelectedRootID"`
}

type MessageRole string

const (
	MessageRoleSystem     MessageRole = "system"
	MessageRoleUser       MessageRole = "user"
	MessageRoleAssistant  MessageRole = "assistant"
	MessageRoleToolCall   MessageRole = "tool_call"
	MessageRoleToolResult MessageRole = "tool_result"
)

type MessageMeta struct {
	GenerationProvider *string `json:"generation_provider,omitempty"`
	GenerationModel    *string `json:"generation_model,omitempty"`
}

type Message struct {
	ID        uint `gorm:"primaryKey"`
	CreatedAt time.Time
	Metadata  MessageMeta

	ConversationID  *uint         `gorm:"index"`
	Conversation    *Conversation `gorm:"foreignKey:ConversationID"`
	ParentID        *uint
	Parent          *Message  `gorm:"foreignKey:ParentID"`
	Replies         []Message `gorm:"foreignKey:ParentID"`
	SelectedReplyID *uint
	SelectedReply   *Message `gorm:"foreignKey:SelectedReplyID"`

	Role        MessageRole
	Content     string
	ToolCalls   ToolCalls   // a json array of tool calls (from the model)
	ToolResults ToolResults // a json array of tool results
}

func (m *MessageMeta) Scan(value interface{}) error {
	return json.Unmarshal(value.([]byte), m)
}

func (m MessageMeta) Value() (driver.Value, error) {
	return json.Marshal(m)
}

func ApplySystemPrompt(m []Message, system string, force bool) []Message {
	if len(m) > 0 && m[0].Role == MessageRoleSystem {
		if force {
			m[0].Content = system
		}
		return m
	} else {
		return append([]Message{{
			Role:    MessageRoleSystem,
			Content: system,
		}}, m...)
	}
}

func (m MessageRole) IsAssistant() bool {
	switch m {
	case MessageRoleAssistant, MessageRoleToolCall:
		return true
	}
	return false
}

func (m MessageRole) IsSystem() bool {
	switch m {
	case MessageRoleSystem:
		return true
	}
	return false
}

// FriendlyRole returns a human friendly signifier for the message's role.
func (m MessageRole) FriendlyRole() string {
	switch m {
	case MessageRoleUser:
		return "You"
	case MessageRoleSystem:
		return "System"
	case MessageRoleAssistant:
		return "Assistant"
	case MessageRoleToolCall:
		return "Tool Call"
	case MessageRoleToolResult:
		return "Tool Result"
	default:
		return string(m)
	}
}