// Package cmdutil provides shared boilerplate for LSP tool command binaries.
package cmdutil

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strconv"

	"ollie/tools/lsp"
)

// PositionArgs are the common args for position-based LSP commands.
type PositionArgs struct {
	Path string `json:"path"`
	Line string `json:"line"`
	Col  string `json:"col"`
}

// ResolvePosition converts the string fields to absolute path and 0-indexed ints.
func (a PositionArgs) ResolvePosition() (file string, line, col int) {
	file, _ = filepath.Abs(a.Path)
	l, _ := strconv.Atoi(a.Line)
	c, _ := strconv.Atoi(a.Col)
	return file, l - 1, c - 1
}

// Run is the common entry point for position-based LSP commands.
// It handles --bridge, reads PositionArgs from stdin, dispatches the request,
// and passes the result to format. If format is nil, raw JSON is printed.
func Run(method string, format func(json.RawMessage)) {
	if len(os.Args) > 1 && os.Args[1] == "--bridge" {
		if err := lsp.RunBridge(); err != nil {
			fmt.Fprintf(os.Stderr, "bridge: %v\n", err)
			os.Exit(1)
		}
		return
	}

	var args PositionArgs
	if err := json.NewDecoder(os.Stdin).Decode(&args); err != nil {
		fmt.Fprintf(os.Stderr, "error: %v\n", err)
		os.Exit(1)
	}

	file, line, col := args.ResolvePosition()

	result, err := lsp.ClientRequest(&lsp.BridgeRequest{
		Method: method,
		File:   file,
		Line:   line,
		Col:    col,
	})
	if err != nil {
		fmt.Fprintf(os.Stderr, "error: %v\n", err)
		os.Exit(1)
	}

	if result == nil || string(result) == "null" {
		fmt.Printf("(no %s found)\n", method)
		return
	}

	if format != nil {
		format(result)
	} else {
		os.Stdout.Write(result)
		fmt.Println()
	}
}

// RunCustom handles --bridge and then calls fn for custom argument handling.
// Use for commands that don't follow the simple position-args pattern
// (e.g. diagnostics, rename, symbols).
func RunCustom(fn func()) {
	if len(os.Args) > 1 && os.Args[1] == "--bridge" {
		if err := lsp.RunBridge(); err != nil {
			fmt.Fprintf(os.Stderr, "bridge: %v\n", err)
			os.Exit(1)
		}
		return
	}
	fn()
}