package progdoc

import (
	"bytes"
	"log"
	"os"
	"path/filepath"
	"strings"
	"text/template"
)

func Path(path string) PathBuilder {
	return PathBuilder{path: path}
}

func (pb PathBuilder) File(file string) Option {
	return Option{
		configSitemap: func(sm *siteMap) error {
			_, err := os.Stat(file)
			if err != nil {
				return err
			}

			// TODO: support things other than markdown
			src, err := inferSourceFromFilename(file)
			if err != nil {
				return err
			}

			log.Printf("Page '%s' -> %s", pb.path, file)
			sm.Pages = append(sm.Pages, sitePage{
				Path:   pb.path,
				Source: stdLayoutSource{MainSource: src},
			})

			return nil
		},
	}
}

func (pb PathBuilder) GoFiles(dir, templateFile string) Option {
	return Option{
		configSitemap: func(sm *siteMap) error {
			tmplBytes, err := os.ReadFile(templateFile)
			if err != nil {
				return err
			}
			tmpl, err := template.New("").Parse(string(tmplBytes))
			if err != nil {
				return err
			}

			if err := filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
				if err != nil {
					return err
				}
				if !info.IsDir() && info.Mode().IsRegular() {
					relPath, err := filepath.Rel(dir, strings.TrimSuffix(path, filepath.Ext(path)))
					if err != nil {
						return nil
					}
					targetPath := filepath.Join(pb.path, relPath)

					absName, err := filepath.Abs(path)
					if err != nil {
						return err
					} else if !strings.HasSuffix(absName, ".go") {
						return nil
					}

					goBts, err := os.ReadFile(path)
					if err != nil {
						return err
					}
					goFileDoc, err := parseGoFileDocs(bytes.NewReader(goBts))
					if err != nil {
						return err
					}

					if !goFileDoc.HasDocs() {
						return nil
					}

					sm.Pages = append(sm.Pages, sitePage{
						Path: targetPath,
						Source: stdLayoutSource{
							MainSource: mdTemplateSource{
								Template: tmpl,
								Data:     goFileDoc,
							},
						},
					})
				}
				return nil
			}); err != nil {
				return err
			}
			return nil
		},
	}
}

func (pb PathBuilder) Dir(dir string) Option {
	return Option{
		configSitemap: func(sm *siteMap) error {
			return filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
				if err != nil {
					return err
				}
				if !info.IsDir() && info.Mode().IsRegular() {
					src, err := inferSourceFromFilename(path)
					if err != nil {
						return nil
					}

					relPath, err := filepath.Rel(dir, strings.TrimSuffix(path, filepath.Ext(path)))
					if err != nil {
						return nil
					}
					targetPath := filepath.Join(pb.path, relPath)

					log.Printf("Page '%s' -> %s", targetPath, path)
					sm.Pages = append(sm.Pages, sitePage{
						Path:   targetPath,
						Source: stdLayoutSource{MainSource: src},
					})
				}
				return nil
			})
		},
	}
}