package tools

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

	"ollie/toolsrv"
)

// ToolList lists all available tools from the global registry.
func ToolList(ctx context.Context, srv *toolsrv.Server, args json.RawMessage) (string, error) {
	reg := srv.ToolRegistry()
	if reg == nil {
		return "", fmt.Errorf("tool_list: no registry available")
	}

	// Refresh loaded tool schemas from disk so the model sees current definitions.
	sid := srv.SessionID()
	if sid != "" {
		reg.RefreshLoaded(sid)
	}

	summaries := reg.Summaries()
	if len(summaries) == 0 {
		return "(no tools 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")
	}

	// Notify the agent that the tool listing may have changed so the
	// preamble stays in sync with the directory contents.
	if srv.OnToolsChanged != nil {
		var listing strings.Builder
		for _, s := range summaries {
			if s.Description != "" {
				fmt.Fprintf(&listing, "- **%s** — %s\n", s.Name, s.Description)
			}
		}
		srv.OnToolsChanged(listing.String())
	}

	return strings.TrimRight(out.String(), "\n"), nil
}

// ToolLoad loads a tool into the current session.
func ToolLoad(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("tool_load: bad args: %w", err)
	}
	if a.Name == "" {
		return "", fmt.Errorf("tool_load: name is required")
	}
	reg := srv.ToolRegistry()
	sid := srv.SessionID()
	if reg == nil || sid == "" {
		return "", fmt.Errorf("tool_load: no session registry")
	}
	if err := reg.Load(sid, a.Name); err != nil {
		return "", fmt.Errorf("tool_load: %w", err)
	}
	return fmt.Sprintf("loaded: %s", a.Name), nil
}

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