package content

import (
	"fmt"
	"regexp"
	"sort"
	"strings"
	"time"

	"gitblog/internal/github"

	"github.com/russross/blackfriday/v2"
)

type Post struct {
	Title       string
	Slug        string
	Content     string
	HTML        string
	Date        time.Time
	Categories  []string
	Tags        []string
	Excerpt     string
	Path        string
	LastUpdated time.Time
}

type Navigation struct {
	Title string
	URL   string
	Order int
}

type Page struct {
	Title   string
	Content string
	HTML    string
	Path    string
}

type Manager struct {
	githubClient *github.Client
	posts        map[string]*Post
	pages        map[string]*Page
	navigation   []Navigation
	lastUpdate   time.Time
}

func NewManager(githubClient *github.Client) *Manager {
	return &Manager{
		githubClient: githubClient,
		posts:        make(map[string]*Post),
		pages:        make(map[string]*Page),
		navigation:   []Navigation{},
	}
}

func (m *Manager) LoadContent() error {
	if err := m.loadPosts(); err != nil {
		return fmt.Errorf("failed to load posts: %w", err)
	}

	if err := m.loadPages(); err != nil {
		return fmt.Errorf("failed to load pages: %w", err)
	}

	if err := m.loadNavigation(); err != nil {
		return fmt.Errorf("failed to load navigation: %w", err)
	}

	m.lastUpdate = time.Now()
	return nil
}

func (m *Manager) loadPosts() error {
	postsDir := "content/posts"
	contents, err := m.githubClient.ListDirectory(postsDir)
	if err != nil {
		return err
	}

	for _, content := range contents {
		if strings.HasSuffix(content.Path, ".md") {
			post, err := m.parsePost(content)
			if err != nil {
				// Log error but continue processing other posts
				fmt.Printf("Warning: failed to parse post %s: %v\n", content.Path, err)
				continue
			}
			if post.Slug != "" {
				m.posts[post.Slug] = post
			}
		}
	}

	return nil
}

func (m *Manager) loadPages() error {
	pagesDir := "content/pages"
	contents, err := m.githubClient.ListDirectory(pagesDir)
	if err != nil {
		return err
	}

	for _, content := range contents {
		if strings.HasSuffix(content.Path, ".md") {
			page, err := m.parsePage(content)
			if err != nil {
				continue
			}
			m.pages[strings.TrimSuffix(content.Path, ".md")] = page
		}
	}

	return nil
}

func (m *Manager) loadNavigation() error {
	navFile := "content/navigation.md"
	content, err := m.githubClient.GetFileContent(navFile)
	if err != nil {
		return err
	}

	lines := strings.Split(content.Content, "\n")
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}

		parts := strings.SplitN(line, "|", 3)
		if len(parts) >= 2 {
			nav := Navigation{
				Title: strings.TrimSpace(parts[0]),
				URL:   strings.TrimSpace(parts[1]),
			}
			if len(parts) == 3 {
				fmt.Sscanf(strings.TrimSpace(parts[2]), "%d", &nav.Order)
			}
			m.navigation = append(m.navigation, nav)
		}
	}

	sort.Slice(m.navigation, func(i, j int) bool {
		return m.navigation[i].Order < m.navigation[j].Order
	})

	return nil
}

func (m *Manager) parsePost(content *github.Content) (*Post, error) {
	lines := strings.Split(content.Content, "\n")

	var frontmatter map[string]interface{}
	var contentStart int

	for i, line := range lines {
		if strings.TrimSpace(line) == "---" {
			if i == 0 {
				frontmatter = m.parseFrontmatter(lines[1:])
				contentStart = i + 1
				break
			}
		}
	}

	contentLines := lines[contentStart:]
	for i, line := range contentLines {
		if strings.TrimSpace(line) == "---" {
			contentLines = contentLines[i+1:]
			break
		}
	}

	post := &Post{
		Content:     strings.Join(contentLines, "\n"),
		Path:        content.Path,
		LastUpdated: content.LastUpdated,
	}

	if title, ok := frontmatter["title"].(string); ok {
		post.Title = title
		post.Slug = m.generateSlug(title)
	}

	if dateStr, ok := frontmatter["date"].(string); ok {
		if date, err := time.Parse("2006-01-02", dateStr); err == nil {
			post.Date = date
		}
	}

	if categories, ok := frontmatter["categories"].([]interface{}); ok {
		for _, cat := range categories {
			if catStr, ok := cat.(string); ok {
				post.Categories = append(post.Categories, catStr)
			}
		}
	}

	if tags, ok := frontmatter["tags"].([]interface{}); ok {
		for _, tag := range tags {
			if tagStr, ok := tag.(string); ok {
				post.Tags = append(post.Tags, tagStr)
			}
		}
	}

	post.HTML = string(blackfriday.Run([]byte(post.Content)))
	post.Excerpt = m.generateExcerpt(post.Content)

	return post, nil
}

func (m *Manager) parsePage(content *github.Content) (*Page, error) {
	lines := strings.Split(content.Content, "\n")

	var frontmatter map[string]interface{}
	var contentStart int

	for i, line := range lines {
		if strings.TrimSpace(line) == "---" {
			if i == 0 {
				frontmatter = m.parseFrontmatter(lines[1:])
				contentStart = i + 1
				break
			}
		}
	}

	contentLines := lines[contentStart:]
	for i, line := range contentLines {
		if strings.TrimSpace(line) == "---" {
			contentLines = contentLines[i+1:]
			break
		}
	}

	page := &Page{
		Content: strings.Join(contentLines, "\n"),
		Path:    content.Path,
	}

	if title, ok := frontmatter["title"].(string); ok {
		page.Title = title
	}

	page.HTML = string(blackfriday.Run([]byte(page.Content)))

	return page, nil
}

func (m *Manager) parseFrontmatter(lines []string) map[string]interface{} {
	frontmatter := make(map[string]interface{})

	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line == "---" {
			break
		}

		parts := strings.SplitN(line, ":", 2)
		if len(parts) == 2 {
			key := strings.TrimSpace(parts[0])
			value := strings.TrimSpace(parts[1])

			if strings.HasPrefix(value, "[") && strings.HasSuffix(value, "]") {
				value = strings.Trim(value, "[]")
				items := strings.Split(value, ",")
				var list []interface{}
				for _, item := range items {
					list = append(list, strings.TrimSpace(item))
				}
				frontmatter[key] = list
			} else {
				frontmatter[key] = value
			}
		}
	}

	return frontmatter
}

func (m *Manager) generateSlug(title string) string {
	if title == "" {
		return "untitled"
	}
	slug := strings.ToLower(title)
	slug = regexp.MustCompile(`[^a-z0-9\s-]`).ReplaceAllString(slug, "")
	slug = regexp.MustCompile(`\s+`).ReplaceAllString(slug, "-")
	slug = strings.Trim(slug, "-")
	if slug == "" {
		return "untitled"
	}
	return slug
}

func (m *Manager) generateExcerpt(content string) string {
	words := strings.Fields(content)
	if len(words) <= 30 {
		return content
	}
	return strings.Join(words[:30], " ") + "..."
}

func (m *Manager) GetPost(slug string) (*Post, bool) {
	post, exists := m.posts[slug]
	return post, exists
}

func (m *Manager) GetAllPosts() []*Post {
	var posts []*Post
	for _, post := range m.posts {
		posts = append(posts, post)
	}

	sort.Slice(posts, func(i, j int) bool {
		return posts[i].Date.After(posts[j].Date)
	})

	return posts
}

func (m *Manager) GetPostsByCategory(category string) []*Post {
	var posts []*Post
	for _, post := range m.posts {
		for _, cat := range post.Categories {
			if cat == category {
				posts = append(posts, post)
				break
			}
		}
	}

	sort.Slice(posts, func(i, j int) bool {
		return posts[i].Date.After(posts[j].Date)
	})

	return posts
}

func (m *Manager) GetPage(path string) (*Page, bool) {
	page, exists := m.pages[path]
	return page, exists
}

func (m *Manager) GetNavigation() []Navigation {
	return m.navigation
}

func (m *Manager) GetLastUpdate() time.Time {
	return m.lastUpdate
}