package progdoc

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

type Option struct {
	configSitemap func(sm *siteMap) error
}

func Meta(meta SiteMeta) Option {
	return Option{
		configSitemap: func(sm *siteMap) error {
			sm.Meta = &meta
			return nil
		},
	}
}

func SourceFile(path, 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", path, file)
			sm.Pages = append(sm.Pages, sitePage{
				Path:   path,
				Source: stdLayoutSource{MainSource: src},
			})

			return nil
		},
	}
}

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

			absName, err := filepath.Abs(file)
			if err != nil {
				return err
			}

			log.Printf("Static '%s' -> %s", path, file)
			sm.Static = append(sm.Static, siteStatic{
				Path: path,
				Source: fileStaticSource{
					Filename: absName,
				},
			})

			return nil
		},
	}
}

func SourceDir(basePath, 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(basePath, relPath)

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

func inferSourceFromFilename(fname string) (pageSource, error) {
	absName, err := filepath.Abs(fname)
	if err != nil {
		return nil, err
	}

	if strings.HasSuffix(absName, ".md") {
		return mdSource{MDFile: absName}, nil
	}
	return nil, errors.New("unsupported file type")
}