package main

import (
	"bytes"
	"log"
	pathpkg "path"
	"strings"
	"time"

	"gopkg.in/yaml.v3"
)

// Page represents a page.
type Page struct {
	Title   string
	Date    time.Time
	Name    string `yaml:"-"`
	Path    string `yaml:"-"`
	Content string `yaml:"-"`
	Params  map[string]string
}

// NewPage returns a new Page with the given path and content.
func NewPage(path string, content []byte) *Page {
	var page Page

	// Try to parse the date from the page filename
	const layout = "2006-01-02"
	base := pathpkg.Base(path)
	if len(base) >= len(layout) {
		dateStr := base[:len(layout)]
		if time, err := time.Parse(layout, dateStr); err == nil {
			page.Date = time
			// Remove the date from the path
			base = base[len(layout):]
			if len(base) > 0 {
				// Remove a leading dash
				if base[0] == '-' {
					base = base[1:]
				}
				if len(base) > 0 {
					dir := pathpkg.Dir(path)
					if dir == "." {
						dir = ""
					}
					path = pathpkg.Join(dir, base)
				}
			}
		}
	}

	// Extract frontmatter from content
	var frontmatter []byte
	frontmatter, content = extractFrontmatter(content)
	if len(frontmatter) != 0 {
		if err := yaml.Unmarshal(frontmatter, &page); err != nil {
			log.Printf("failed to parse frontmatter for %q: %v", path, err)
		}

		// Trim leading newlines from content
		content = bytes.TrimLeft(content, "\r\n")
	}

	// Remove extension from path
	// TODO: Allow using ugly URLs
	path = strings.TrimSuffix(path, pathpkg.Ext(path))
	page.Name = pathpkg.Base(path)
	page.Path = "/" + path + "/"
	page.Content = string(content)
	return &page
}