package prompt

import "strings"

const overlaySeparator = "\n\n---\n\n"

// ComposeSystem prepends global overlay to the base system prompt before provider send.
func ComposeSystem(base string) (string, error) {
	base = strings.TrimSpace(base)
	overlayText, err := Overlay()
	if err != nil {
		return "", err
	}
	overlayText = strings.TrimSpace(overlayText)
	if overlayText == "" {
		return base, nil
	}
	if base == "" {
		return overlayText, nil
	}
	return overlayText + overlaySeparator + base, nil
}

// Style8DSystem loads 8D slots from config files and composes the outgoing system prompt.
func Style8DSystem() (string, error) {
	system, err := Slot(KeyStyle8DSystem)
	if err != nil {
		return "", err
	}
	schema, err := Slot(KeyStyle8DSchema)
	if err != nil {
		return "", err
	}
	return ComposeSystem(system + schema)
}

// IslanderSystem composes the islander guide system prompt with optional live page context.
func IslanderSystem(pageContext string) (string, error) {
	base, err := Slot(KeyIslanderSystem)
	if err != nil {
		return "", err
	}
	pageContext = strings.TrimSpace(pageContext)
	if pageContext != "" {
		base = base + "\n\n---\n\n" + pageContext
	}
	return ComposeSystem(base)
}

// AIChatSystem composes the outgoing system prompt for console AI chat.
func AIChatSystem(clientSystem string) (string, error) {
	base := strings.TrimSpace(clientSystem)
	if base == "" {
		var err error
		base, err = Slot(KeyAIChatSystem)
		if err != nil {
			return "", err
		}
	}
	return ComposeSystem(base)
}