/*
 * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package main

import (
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"

	"github.com/goplus/llgo/c"
	"github.com/goplus/llgo/c/cjson"
	"github.com/goplus/llgo/chore/_xtool/llcppsigfetch/parse"
	"github.com/goplus/llgo/chore/_xtool/llcppsymg/config"
)

func main() {
	if len(os.Args) == 1 {
		// run with default config file
		runFromConfig()
		return
	}

	if os.Args[1] == "--extract" {
		runExtract()
	} else if os.Args[1] == "--help" || os.Args[1] == "-h" {
		printUsage()
	} else {
		runFromConfig()
	}
}

func printUsage() {
	fmt.Println("Usage:")
	fmt.Println("  llcppsigfetch [<config_file>]")
	fmt.Println("  OR")
	fmt.Println("  llcppsigfetch --extract <file> <temp> [args...]")
	fmt.Println("")
	fmt.Println("Options:")
	fmt.Println("  [<config_file>]: Path to the configuration file (use '-' for stdin)")
	fmt.Println("                   If not provided, uses default 'llcppg.cfg'")
	fmt.Println("")
	fmt.Println("  --extract:       Extract information from a single file")
	fmt.Println("    <file>:        When <temp> is false: the path to the file to process")
	fmt.Println("                   When <temp> is true: the content of the file to process")
	fmt.Println("    <temp>:        'true' if <file> contains file content, 'false' if it's a file path")
	fmt.Println("    [args]:        Optional additional arguments (default: -x c++ -std=c++11)")
	fmt.Println("")
	fmt.Println("  --help, -h:      Show this help message")
	fmt.Println("")
	fmt.Println("Note: The two usage modes are mutually exclusive. Use either [<config_file>] OR --extract, not both.")
}

func runFromConfig() {
	cfgFile := "llcppg.cfg"
	if len(os.Args) > 1 {
		cfgFile = os.Args[1]
	}

	var data []byte
	var err error
	if cfgFile == "-" {
		data, err = io.ReadAll(os.Stdin)
	} else {
		data, err = os.ReadFile(cfgFile)
	}
	check(err)

	conf, err := config.GetConf(data)
	check(err)
	defer conf.Delete()

	if err != nil {
		fmt.Fprintln(os.Stderr, "Failed to parse config file:", cfgFile)
	}

	files := getHeaderFiles(conf.CFlags, conf.Include)

	context := parse.NewContext()
	err = context.ProcessFiles(files)
	check(err)

	outputInfo(context)
}

func runExtract() {
	if len(os.Args) < 4 {
		printUsage()
		os.Exit(1)
	}

	cfg := &parse.Config{
		File: os.Args[2],
		Temp: os.Args[3] == "true",
		Args: os.Args[4:],
	}
	if !cfg.Temp {
		absPath, err := filepath.Abs(cfg.File)
		check(err)
		cfg.File = absPath
		println(cfg.File)
	}

	converter, err := parse.NewConverter(cfg)
	check(err)
	_, err = converter.Convert()
	check(err)
	result := converter.MarshalASTFiles()
	cstr := result.Print()
	c.Printf(cstr)
	cjson.FreeCStr(cstr)
	result.Delete()
	converter.Dispose()
}

func check(err error) {
	if err != nil {
		panic(err)
	}
}

func getHeaderFiles(cflags string, files []string) []string {
	prefix := cflags
	prefix = strings.TrimPrefix(prefix, "-I")
	var paths []string
	for _, f := range files {
		paths = append(paths, filepath.Join(prefix, f))
	}
	return paths
}

func outputInfo(context *parse.Context) {
	info := context.Output()
	str := info.Print()
	defer cjson.FreeCStr(str)
	defer info.Delete()
	c.Printf(str)
}