package main

import (
	"path/filepath"
	"strings"
	"text/template"
)

type Manipulator struct {
	Pages map[string]*Page

	// Templates
	Templates *template.Template
}

func NewManipulator() (*Manipulator, error) {
	tmpl, err := template.New("templates").ParseGlob("templates/*.gmi")
	if err != nil {
		return nil, err
	}
	return &Manipulator{
		Pages:     map[string]*Page{},
		Templates: tmpl,
	}, nil
}

func (m *Manipulator) Manipulate(index *Index) error {
	for path := range index.Files {
		switch filepath.Ext(path) {
		case ".gmi":
			// Gather page data
			content := string(index.Files[path])
			page := NewPage(path, content)

			builder := &strings.Builder{}
			tmpl := m.Templates.Lookup("page.gmi")
			if err := tmpl.Execute(builder, page); err != nil {
				return err
			}
			page.Content = builder.String()
			m.Pages[path] = page
			index.Files[path] = []byte(page.Content)
		}
	}

	for dir := range index.Dirs {
		// Load section data
		section := NewSection(dir)
		for _, path := range index.Dirs[dir] {
			switch filepath.Ext(path) {
			case ".gmi":
				section.Pages = append(section.Pages, m.Pages[path])
			}
		}

		dstPath := filepath.Join(dir, "index.gmi")
		builder := &strings.Builder{}
		tmpl := m.Templates.Lookup("section.gmi")
		if err := tmpl.Execute(builder, section); err != nil {
			return err
		}
		index.Files[dstPath] = []byte(builder.String())
	}

	return nil
}