// Package tools holds the plugin's chat tools.
package tools

import (
	"bytes"
	"context"
	"fmt"
	"os"

	"[[.SDKModule]]/pluginsdk"
)

// All returns every chat tool. Each is also listed in plugin.json.
func All() []pluginsdk.Tool {
	return []pluginsdk.Tool{countLines, saveSummary}
}

var pathParam = map[string]any{
	"type": "object",
	"properties": map[string]any{
		"path": map[string]any{"type": "string", "description": "The text file, as the user named it."},
	},
	"required": []string{"path"},
}

var countLines = pluginsdk.Tool{
	Name:        "[[.Short]]_count_lines",
	Description: "Count the lines in a text file. Use when the user asks how long a text file is. Returns the line count.",
	Parameters:  pathParam,
	Run: func(ctx context.Context, h *pluginsdk.Host, call pluginsdk.ToolCall) pluginsdk.ToolResult {
		path, lines, err := count(ctx, h, call)
		if err != nil {
			return pluginsdk.Fail("%v", err)
		}
		return pluginsdk.Text("%s has %d lines.", path, lines)
	},
}

var saveSummary = pluginsdk.Tool{
	Name:        "[[.Short]]_save_summary",
	Description: "Save a one-line summary (the line count) next to a text file, as <file>.summary.txt. Use only when the user asks to save it.",
	Parameters:  pathParam,
	Mutating:    true,
	Run: func(ctx context.Context, h *pluginsdk.Host, call pluginsdk.ToolCall) pluginsdk.ToolResult {
		path, lines, err := count(ctx, h, call)
		if err != nil {
			return pluginsdk.Fail("%v", err)
		}
		out := path + ".summary.txt"
		allowed, err := h.CanWrite(ctx, out)
		if err != nil {
			return pluginsdk.Fail("%v", err)
		}
		if !allowed || !call.EditMode {
			return pluginsdk.Fail("Cletus doesn't allow edits in this folder. Ask the user to allow edits, then try again.")
		}
		if err := os.WriteFile(out, []byte(fmt.Sprintf("%d lines\n", lines)), 0o644); err != nil {
			return pluginsdk.Fail("Couldn't save the summary: %v", err)
		}
		return pluginsdk.Text("Saved %s.", out)
	},
}

// count resolves the path through the host and counts its lines.
func count(ctx context.Context, h *pluginsdk.Host, call pluginsdk.ToolCall) (string, int, error) {
	var args struct {
		Path string `json:"path"`
	}
	if err := call.Decode(&args); err != nil {
		return "", 0, err
	}
	if args.Path == "" {
		return "", 0, fmt.Errorf("give the path of a text file")
	}
	path, err := h.ResolvePath(ctx, args.Path)
	if err != nil {
		return "", 0, err
	}
	data, err := os.ReadFile(path)
	if err != nil {
		return "", 0, fmt.Errorf("couldn't read %s: %v", args.Path, err)
	}
	lines := bytes.Count(data, []byte("\n"))
	if len(data) > 0 && data[len(data)-1] != '\n' {
		lines++
	}
	return path, lines, nil
}