htmlc.go

package htmlc

import (
	"errors"
	"os"
	"path/filepath"
	"strings"

	_ "embed"

	regex "github.com/tkdeng/goregex"
	"github.com/tkdeng/goutil"
)

//todo: allow dynamic compiling and listening for file changes

//go:embed template.exs
var template []byte

func Compile(src string, out string) error {
	if stat, err := os.Stat(src); err != nil || !stat.IsDir() {
		return errors.Join(err, os.ErrNotExist, errors.New("src \""+src+"\": directory not found"))
	}

	if err := os.MkdirAll(filepath.Dir(out), 0755); err != nil {
		return err
	}

	outfile, err := os.OpenFile(out, os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0755)
	if err != nil {
		return err
	}
	defer outfile.Close()

	outfile.Write(template)

	usedRandID := [][]byte{}

	if err = compileDir(outfile, src, "", 'r', &usedRandID); err != nil {
		return err
	}

	return nil
}

func compileDir(out *os.File, dir string, name string, dirType byte, usedRandID *[][]byte) error {
	files, err := os.ReadDir(dir)
	if err != nil {
		return err
	}
	for _, file := range files {
		if file.IsDir() {
			if path, err := goutil.JoinPath(dir, file.Name()); err == nil {
				if dirType == 'r' {
					switch file.Name() {
					case "layouts", "layout":
						if err = compileDir(out, path, "", 'l', usedRandID); err != nil {
							return err
						}
					case "widgets", "widget":
						if err = compileDir(out, path, "", 'w', usedRandID); err != nil {
							return err
						}
					case "pages", "page":
						if err = compileDir(out, path, "", 'p', usedRandID); err != nil {
							return err
						}
					case "errors", "error":
						if err = compileDir(out, path, "", 'e', usedRandID); err != nil {
							return err
						}
					default:
						if err = compileDir(out, path, file.Name(), 'd', usedRandID); err != nil {
							return err
						}
					}
				} else {
					if err = compileDir(out, path, name+"/"+file.Name(), dirType, usedRandID); err != nil {
						return err
					}
				}
			}
		} else if strings.HasSuffix(file.Name(), ".html") {
			if path, err := goutil.JoinPath(dir, file.Name()); err == nil {
				if buf, err := os.ReadFile(path); err == nil {
					n := name
					if n != "" {
						n += "/"
					}
					n += strings.TrimSuffix(file.Name(), ".html")

					if dirType == 'l' {
						comp := compileExs{buf: &buf}
						if err := comp.compile(); err != nil {
							return err
						}
						loadLayout(out, n, &buf, usedRandID)
					} else if dirType == 'w' {
						comp := compileExs{buf: &buf}
						if err := comp.compile(); err != nil {
							return err
						}
						loadWidget(out, n, &buf, usedRandID)
					} else if dirType == 'p' || dirType == 'e' {
						buf_page := map[string][]byte{}

						regex.Comp(`(?s)<(_?@)([\w_-]+)>(.*)</\1\2>\r?\n?`).RepFunc(buf, func(data func(int) []byte) []byte {
							name := string(data(2))
							if _, ok := buf_page[name]; !ok {
								buf_page[name] = data(3)
							} else {
								buf_page[name] = append(buf_page[name], data(3)...)
							}
							return []byte{}
						})

						if len(buf_page) == 0 {
							buf_page["body"] = buf
						}

						for k, b := range buf_page {
							comp := compileExs{buf: &b}
							if err := comp.compile(); err != nil {
								return err
							}
							buf_page[k] = b
						}
						loadPage(out, n, &buf_page, usedRandID)
					} else {
						var buf_layout []byte
						buf_page := map[string][]byte{}

						buf = regex.Comp(`(?s)(<!DOCTYPE(?:\s+[^>]*|)>|<html(?:\s+[^>]*|)>(.*)</html>)\r?\n?`).RepFunc(buf, func(data func(int) []byte) []byte {
							buf_layout = append(buf_layout, data(0)...)
							return []byte{}
						})

						buf = regex.Comp(`(?s)<(_?@)([\w_-]+)>(.*)</\1\2>\r?\n?`).RepFunc(buf, func(data func(int) []byte) []byte {
							id := string(data(2))
							if _, ok := buf_page[id]; !ok {
								buf_page[id] = data(3)
							} else {
								buf_page[id] = append(buf_page[id], data(3)...)
							}
							return []byte{}
						})

						if len(buf_layout) != 0 {
							comp := compileExs{buf: &buf_layout}
							if err := comp.compile(); err != nil {
								return err
							}
							loadLayout(out, n, &buf_layout, usedRandID)
						}

						if len(buf_page) != 0 {
							for k, b := range buf_page {
								comp := compileExs{buf: &b}
								if err := comp.compile(); err != nil {
									return err
								}
								buf_page[k] = b
							}
							loadPage(out, n, &buf_page, usedRandID)
						}

						if len(buf) != 0 && len(regex.Comp(`(?s)[\s\r\n\t ]+`).RepStrLit(buf, []byte{})) != 0 {
							comp := compileExs{buf: &buf}
							if err := comp.compile(); err != nil {
								return err
							}
							loadWidget(out, n, &buf, usedRandID)
						}
					}
				}
			}
		}
	}

	return nil
}