aego/app/docstool/site.go

package docstool

import (
	"bytes"
	"crypto/sha256"
	"encoding/hex"
	"errors"
	"fmt"
	"io"
	"io/fs"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"aego/engine"
	"aego/engine/module"
	"aego/project"
)

type Env struct {
	Project *project.Project
	Engine  string
	Modules []module.Module
	Native  func(args ...string) error
	Stdout  io.Writer
	Stderr  io.Writer
	Repo    string
}

func (e *Env) export(path string) error {
	if e.Native != nil {
		args := []string{"docs", "export"}
		if path != "" {
			args = append(args, "--out", path)
		}
		return e.Native(args...)
	}
	reg, err := Registry(e.Project, e.Modules)
	if err != nil {
		return err
	}
	return WriteExport(reg, Title(e.Project), path, e.Stdout)
}

func (e *Env) Export(path string) int {
	if err := e.export(path); err != nil {
		fmt.Fprintln(e.Stderr, "aego:", err)
		return 1
	}
	return 0
}

func (e *Env) Check(strict bool) int {
	if e.Native != nil {
		args := []string{"docs", "check"}
		if strict {
			args = append(args, "--strict")
		}
		if err := e.Native(args...); err != nil {
			return 1
		}
		return 0
	}
	reg, err := Registry(e.Project, e.Modules)
	if err != nil {
		fmt.Fprintln(e.Stderr, "aego:", err)
		return 1
	}
	return Check(reg, strict, e.Stdout)
}

func (e *Env) goCmd(dir string, env []string, args ...string) error {
	cmd := exec.Command("go", args...)
	cmd.Dir = dir
	cmd.Env = append(os.Environ(), env...)
	cmd.Stdout = e.Stdout
	cmd.Stderr = e.Stderr
	return cmd.Run()
}

const defaultBranch = "master"

func (e *Env) git(args ...string) string {
	out, err := exec.Command("git", append([]string{"-C", e.Engine}, args...)...).Output()
	if err != nil {
		return ""
	}
	return strings.TrimSpace(string(out))
}

func (e *Env) commit() string {
	return e.git("rev-parse", "--short", "HEAD")
}

func (e *Env) branch() string {
	if b := e.git("rev-parse", "--abbrev-ref", "HEAD"); b != "" && b != "HEAD" {
		return b
	}
	return defaultBranch
}

func (e *Env) Build(out string, play bool) error {
	if e.Engine == "" {
		return errors.New("cannot locate the aego source tree; pass --engine <dir> or set AEGO_ROOT")
	}
	abs, err := filepath.Abs(out)
	if err != nil {
		return err
	}
	if err := os.MkdirAll(abs, 0o755); err != nil {
		return err
	}
	tmp, err := os.CreateTemp("", "aego-docs-*.json")
	if err != nil {
		return err
	}
	tmp.Close()
	defer os.Remove(tmp.Name())
	if err := e.export(tmp.Name()); err != nil {
		return err
	}
	args := []string{"run", ".", "-in", tmp.Name(), "-out", abs, "-version", engine.Version}
	if play {
		args = append(args, "-playground")
	}
	if e.Repo != "" {
		args = append(args, "-repo", e.Repo, "-edit", strings.TrimRight(e.Repo, "/")+"/src/branch/"+e.branch())
	}
	if c := e.commit(); c != "" {
		args = append(args, "-commit", c)
	}
	if hero := filepath.Join(e.Engine, "docs", "hero.png"); fileExists(hero) {
		args = append(args, "-hero", hero)
	}
	if err := e.goCmd(filepath.Join(e.Engine, "tools", "gendocs"), nil, args...); err != nil {
		return fmt.Errorf("gendocs failed: %w", err)
	}
	if play {
		return e.playground(filepath.Join(abs, "play"))
	}
	return nil
}

func fileExists(p string) bool {
	st, err := os.Stat(p)
	return err == nil && !st.IsDir()
}

func copyFile(src, dst string) error {
	data, err := os.ReadFile(src)
	if err != nil {
		return err
	}
	return os.WriteFile(dst, data, 0o644)
}

func (e *Env) playground(dir string) error {
	if err := os.MkdirAll(dir, 0o755); err != nil {
		return err
	}
	wasm := filepath.Join(dir, "aego.wasm")
	if err := e.goCmd(e.Engine, []string{"GOOS=js", "GOARCH=wasm"}, "build", "-trimpath", "-ldflags", "-s -w", "-o", wasm, "./cmd/aego-playground"); err != nil {
		return fmt.Errorf("playground build failed: %w", err)
	}
	root, err := exec.Command("go", "env", "GOROOT").Output()
	if err != nil {
		return err
	}
	if err := copyFile(filepath.Join(strings.TrimSpace(string(root)), "lib", "wasm", "wasm_exec.js"), filepath.Join(dir, "wasm_exec.js")); err != nil {
		return err
	}
	web := filepath.Join(e.Engine, "cmd", "aego-playground", "web")
	files, err := os.ReadDir(web)
	if err != nil {
		return err
	}
	info, err := os.Stat(wasm)
	if err != nil {
		return err
	}
	blob, err := os.ReadFile(wasm)
	if err != nil {
		return err
	}
	h := sha256.New()
	h.Write(blob)
	for _, f := range files {
		if f.IsDir() {
			continue
		}
		data, err := os.ReadFile(filepath.Join(web, f.Name()))
		if err != nil {
			return err
		}
		h.Write(data)
	}
	version := hex.EncodeToString(h.Sum(nil)[:5])
	for _, f := range files {
		if f.IsDir() {
			continue
		}
		src, dst := filepath.Join(web, f.Name()), filepath.Join(dir, f.Name())
		if f.Name() != "index.html" {
			if err := copyFile(src, dst); err != nil {
				return err
			}
			continue
		}
		data, err := os.ReadFile(src)
		if err != nil {
			return err
		}
		data = bytes.ReplaceAll(data, []byte(`data-wasm-size="0"`), []byte(`data-wasm-size="`+strconv.FormatInt(info.Size(), 10)+`"`))
		data = bytes.ReplaceAll(data, []byte(`data-version="dev"`), []byte(`data-version="`+version+`"`))
		data = bytes.ReplaceAll(data, []byte(`?v=dev"`), []byte(`?v=`+version+`"`))
		if err := os.WriteFile(dst, data, 0o644); err != nil {
			return err
		}
	}
	return nil
}

func (e *Env) watched() []string {
	var roots []string
	if e.Engine != "" {
		roots = append(roots, e.Engine)
	}
	if e.Project != nil && e.Project.Root != e.Engine {
		roots = append(roots, e.Project.Root)
	}
	return roots
}

func skipDir(name string) bool {
	return strings.HasPrefix(name, ".") || name == "site" || name == "node_modules" || name == "third_party"
}

func (e *Env) stamp() string {
	var n, size int64
	var latest time.Time
	for _, root := range e.watched() {
		filepath.WalkDir(root, func(p string, d fs.DirEntry, err error) error {
			if err != nil {
				return nil
			}
			if d.IsDir() {
				if p != root && skipDir(d.Name()) {
					return filepath.SkipDir
				}
				return nil
			}
			slash := filepath.ToSlash(p)
			doc := strings.HasSuffix(slash, ".md") && strings.Contains(slash, "/res/docs/")
			if !doc && filepath.Ext(p) != ".aes" {
				return nil
			}
			info, err := d.Info()
			if err != nil {
				return nil
			}
			n++
			size += info.Size()
			if info.ModTime().After(latest) {
				latest = info.ModTime()
			}
			return nil
		})
	}
	return strconv.FormatInt(n, 10) + ":" + strconv.FormatInt(size, 10) + ":" + latest.String()
}

func (e *Env) watch(out string) {
	last := e.stamp()
	for range time.Tick(time.Second) {
		s := e.stamp()
		if s == last {
			continue
		}
		last = s
		start := time.Now()
		if err := e.Build(out, false); err != nil {
			fmt.Fprintln(e.Stderr, "docs:", err)
			continue
		}
		fmt.Fprintf(e.Stdout, "docs: rebuilt in %s\n", time.Since(start).Round(time.Millisecond))
	}
}

func noCache(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Cache-Control", "no-store")
		h.ServeHTTP(w, r)
	})
}

func (e *Env) Serve(addr, out string, play bool) error {
	if err := e.Build(out, play); err != nil {
		return err
	}
	go e.watch(out)
	fmt.Fprintf(e.Stdout, "docs: serving %s on http://%s\n", out, addr)
	return http.ListenAndServe(addr, noCache(http.FileServer(http.Dir(out))))
}