package tools

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"

	"ollie/toolsrv"
)

// SkillList lists all available skills from the global registry.
func SkillList(ctx context.Context, srv *toolsrv.Server, args json.RawMessage) (string, error) {
	reg := srv.SkillsRegistry()
	if reg == nil {
		return "", fmt.Errorf("skill_list: no skills registry available")
	}
	summaries := reg.Summaries()
	if len(summaries) == 0 {
		return "(no skills found)", nil
	}
	var out strings.Builder
	for _, s := range summaries {
		out.WriteString(s.Name)
		if s.Description != "" {
			out.WriteString(" — ")
			out.WriteString(s.Description)
		}
		out.WriteString("\n")
	}
	return strings.TrimRight(out.String(), "\n"), nil
}

// SkillLoad loads a skill into the current session.
func SkillLoad(ctx context.Context, srv *toolsrv.Server, args json.RawMessage) (string, error) {
	var a struct {
		Name string `json:"name"`
	}
	if err := json.Unmarshal(args, &a); err != nil {
		return "", fmt.Errorf("skill_load: bad args: %w", err)
	}
	if a.Name == "" {
		return "", fmt.Errorf("skill_load: name is required")
	}
	reg := srv.SkillsRegistry()
	sid := srv.SessionID()
	if reg == nil || sid == "" {
		return "", fmt.Errorf("skill_load: no session registry")
	}
	if err := reg.Load(sid, a.Name); err != nil {
		return "", fmt.Errorf("skill_load: %w", err)
	}
	content, err := reg.SkillContent(a.Name)
	if err != nil {
		return "", fmt.Errorf("skill_load: %w", err)
	}
	injectMsg := fmt.Sprintf("[system: loaded skill %s]\n\n%s", a.Name, content)
	srv.InjectContent(injectMsg)
	return fmt.Sprintf("loaded: %s (%d bytes)", a.Name, len(content)), nil
}

// SkillActive lists skills currently loaded in this session.
func SkillActive(ctx context.Context, srv *toolsrv.Server, args json.RawMessage) (string, error) {
	reg := srv.SkillsRegistry()
	sid := srv.SessionID()
	if reg == nil || sid == "" {
		return "(no skills loaded)", nil
	}
	loaded := reg.Loaded(sid)
	if len(loaded) == 0 {
		return "(no skills loaded)", nil
	}
	var out strings.Builder
	for _, s := range loaded {
		out.WriteString(s.Name)
		if s.Description != "" {
			out.WriteString(" — ")
			out.WriteString(s.Description)
		}
		out.WriteString("\n")
	}
	return strings.TrimRight(out.String(), "\n"), nil
}