package view

import (
	"fmt"
	"html/template"
	"net/http"
	"os"
	"slices"

	"arimelody-web/controller"
	"arimelody-web/model"
	"arimelody-web/templates"

	"github.com/gomarkdown/markdown"
	"github.com/gomarkdown/markdown/html"
	"github.com/gomarkdown/markdown/parser"
)

type (
    blogView struct {
        Collections []*blogPostCollection
    }

    blogPostCollection struct {
        Year int
        Posts []*model.BlogPost
    }

    blogPostView struct {
        *model.BlogPost
        BlogHTML template.HTML
        Comments []*model.ThreadViewPost
        Likes int
        Boosts int
        BlueskyURL string
        MastodonURL string
    }
)

func (c *blogPostCollection) Clone() blogPostCollection {
    return blogPostCollection{
        Year: c.Year,
        Posts: slices.Clone(c.Posts),
    }
}

var mdRenderer = html.NewRenderer(html.RendererOptions{
	Flags: html.CommonFlags | html.HrefTargetBlank,
})

func BlogHandler(app *model.AppState) http.Handler {
    mux := http.NewServeMux()

    mux.HandleFunc("/{id}", func(w http.ResponseWriter, r *http.Request) {
        ServeBlogPost(app, r.PathValue("id")).ServeHTTP(w, r)
    })

	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        posts, err := controller.GetBlogPosts(app.DB, true, -1, 0)
        if err != nil {
			fmt.Fprintf(os.Stderr, "WARN: Failed to fetch blog posts: %v\n", err)
            http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
            return
        }

        collections := []*blogPostCollection{}
        collection := blogPostCollection{
            Posts: []*model.BlogPost{},
            Year: -1,
        }
        for i, post := range posts {
            if i == 0 {
                collection.Year = post.PublishDate.Year()
            }

            if post.PublishDate.Year() != collection.Year {
                clone := collection.Clone()
                collections = append(collections, &clone)
                collection = blogPostCollection{
                    Year: post.PublishDate.Year(),
                    Posts: []*model.BlogPost{},
                }
            }

            collection.Posts = append(collection.Posts, post)

            if i == len(posts) - 1 {
                collections = append(collections, &collection)
            }
        }

		err = templates.BlogTemplate.Execute(w, blogView{
            Collections: collections,
		})
		if err != nil {
            fmt.Fprintf(os.Stderr, "WARN: Error rendering blog post: %v\n", err)
            http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
            return
		}
	})

    return mux
}

func ServeBlogPost(app *model.AppState, blogPostID string) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		blog, err := controller.GetBlogPost(app.DB, blogPostID)
        if err != nil {
			fmt.Fprintf(os.Stderr, "WARN: Failed to fetch blog post %s: %v\n", blogPostID, err)
            http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
            return
        }
        if blog == nil {
            http.NotFound(w, r)
            return
        }

        if !blog.Visible {
            session, err := controller.GetSessionFromRequest(app, r)
            if err != nil {
                fmt.Fprintf(os.Stderr, "WARN: Failed to retrieve session: %v\n", err)
                http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
                return
            }

            if session == nil || session.Account == nil {
                http.NotFound(w, r)
                return
            }
        }

		// blog.Markdown += " <i class=\"end-mark\"></i>"

		mdParser := parser.NewWithExtensions(parser.CommonExtensions | parser.AutoHeadingIDs)
		md := mdParser.Parse([]byte(blog.Markdown))
        blogHTML := template.HTML(markdown.Render(md, mdRenderer))

		comments := []*model.ThreadViewPost{}
        likeCount := 0
        boostCount := 0
        var blueskyURL string
        var blueskyPost *model.ThreadViewPost
        if blog.Bluesky != nil {
            blueskyPost, err = controller.FetchThreadViewPost(blog.Bluesky.ActorDID, blog.Bluesky.RecordID)
            if err != nil {
                fmt.Fprintf(os.Stderr, "WARN: Failed to fetch blog post Bluesky thread: %v\n", err)
            } else {
                comments = append(comments, blueskyPost.Replies...)
                likeCount += blueskyPost.Post.LikeCount
                boostCount += blueskyPost.Post.RepostCount
                blueskyURL = fmt.Sprintf("https://bsky.app/profile/%s/post/%s", blueskyPost.Post.Author.Handle, blog.Bluesky.RecordID)
            }
        }

		err = templates.BlogPostTemplate.Execute(w, blogPostView{
			BlogPost: blog,
            BlogHTML: blogHTML,
			Comments: comments,
			Likes: likeCount,
			Boosts: boostCount,
			BlueskyURL: blueskyURL,
		})
		if err != nil {
            fmt.Fprintf(os.Stderr, "WARN: Error rendering blog post: %v\n", err)
            http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
            return
		}
	})
}