package blog

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"github.com/go-chi/chi"
	"github.com/go-chi/jwtauth"
	"github.com/go-chi/render"
	"github.com/gosimple/slug"
	"net/http"
	"strings"
	"time"
)

var (
	DB        *sql.DB
	TokenAuth *jwtauth.JWTAuth
)

type BlogPost struct {
	ID            int       `json:"id",db:"id"`
	Title         string    `json:"title",db:"title"`
	Slug          string    `json:"slug",db:"slug"`
	Author        string    `json:"author",db:"author"`
	Content       string    `json:"content",db:"content"`
	DatePublished time.Time `json:"date", db:"date"`
	Updated       bool      `json:"updated", db:"updated"`
	UpdateTime    time.Time `json:"update_time", db:"update_time"`
}

type Tag struct {
	TagList string `json:"tags"`
}

type NewBlogPost struct {
	Title   string `json:"title",db:"title"`
	Content string `json:"content",db:"content"`
	Tags    string `json:"tags"`
	Author  string `json:"author",db:"author"`
}

type ReturnError struct {
	Message string `json:"error"`
}

type ReturnSuccess struct {
	Message string `json:"success"`
	ID      int    `json:"id"`
}

func Init() {
	createPostsTable := `
	CREATE TABLE IF NOT EXISTS posts
	(id SERIAL PRIMARY KEY,
    title text,
    slug text,
	author text REFERENCES users (username),
    content text,
	date timestamp,
    updated bool,
    update_time timestamp)`
	DB.Exec(createPostsTable)

	createTagsTable := `
	CREATE TABLE IF NOT EXISTS tags
	(id SERIAL PRIMARY KEY,
    tag text,
	article_id int REFERENCES posts (id))`
	DB.Exec(createTagsTable)
}

func Routes() *chi.Mux {
	r := chi.NewRouter()
	r.Group(func(r chi.Router) {
		r.Use(jwtauth.Verifier(TokenAuth))
		r.Use(jwtauth.Authenticator)
		r.Post("/", createBlogPost)
		r.Patch("/by-id/{id}", updateBlogPostById)
	})
	r.Get("/", getBlogPosts)
	r.Get("/{slug}", getBlogPostBySlug)
	r.Get("/by-id/{id}", getBlogPostById)
	r.Get("/by-tag/{tag}", getBlogPostsByTag)
	r.Get("/by-author/{author}", getBlogPostsByAuthor)
	return r
}

func createBlogPost(w http.ResponseWriter, r *http.Request) {
	returnError := ReturnError{}
	newBlogPost := &NewBlogPost{}
	// basic checks
	_, claims, _ := jwtauth.FromContext(r.Context())
	username := claims["username"].(string)
	err := json.NewDecoder(r.Body).Decode(newBlogPost)
	if err != nil {
		returnError.Message = "unknown error, try again later"
		w.WriteHeader(http.StatusBadRequest)
		return
	}
	if newBlogPost.Title == "" {
		returnError.Message = "title is required"
		w.WriteHeader(http.StatusBadRequest)
		render.JSON(w, r, returnError)
		return
	}
	if newBlogPost.Content == "" {
		returnError.Message = "content is required"
		w.WriteHeader(http.StatusBadRequest)
		render.JSON(w, r, returnError)
		return
	}
	as := slug.Make(newBlogPost.Title)
	slugCheck := DB.QueryRow("SELECT id FROM posts WHERE slug=$1", as)
	// wow this is ugly. someone pls send help.
	// checking to ensure the same slug doesn't exist...
	scr := 0
	err = slugCheck.Scan(&scr)
	if err == nil {
		returnError.Message = "slug already exists"
		w.WriteHeader(http.StatusBadRequest)
		render.JSON(w, r, returnError)
		return
	}
	if err != nil {
		if err != sql.ErrNoRows {
			returnError.Message = "something is super broken..."
			w.WriteHeader(http.StatusInternalServerError)
			return
		}
	}
	s := `INSERT INTO posts (title, slug, author, content, date, updated, update_time)
            VALUES ($1, $2, $3, $4, $5, $6, $7)
            RETURNING id`
	article_id := 0
	// write the row and get back the id
	err = DB.QueryRow(s, newBlogPost.Title, as, username, newBlogPost.Content, time.Now().UTC(), false, time.Now().UTC()).Scan(&article_id)
	if err != nil {
		if err == sql.ErrNoRows {
			returnError.Message = "something is super broken..."
			w.WriteHeader(http.StatusInternalServerError)
			render.JSON(w, r, returnError)
			return
		}
		returnError.Message = "something is super broken..."
		w.WriteHeader(http.StatusInternalServerError)
		render.JSON(w, r, returnError)
		return
	}
	// if the article has tags
	if newBlogPost.Tags != "" {
		t := `INSERT INTO tags (tag, article_id)
                VALUES ($1, $2)`
		tags := strings.Split(newBlogPost.Tags, ",")
		for i := range tags {
			DB.Exec(t, tags[i], article_id)
		}

	}
	returnSuccess := ReturnSuccess{Message: "post created", ID: article_id}
	w.WriteHeader(http.StatusCreated)
	render.JSON(w, r, returnSuccess)
	return
}

func updateBlogPostById(w http.ResponseWriter, r *http.Request) {
	returnError := ReturnError{}
	// Get the actual post
	id := chi.URLParam(r, "id")
	result := DB.QueryRow("SELECT id, title, slug, author, content, date FROM posts WHERE id=$1", id)
	post := BlogPost{}
	err := result.Scan(&post.ID, &post.Title, &post.Slug, &post.Author, &post.Content, &post.DatePublished)
	if err != nil {
		if err == sql.ErrNoRows {
			returnError.Message = "blog post requested for update not found"
			w.WriteHeader(http.StatusInternalServerError)
			render.JSON(w, r, returnError)
			return
		}
		returnError.Message = "something is super broken..."
		w.WriteHeader(http.StatusInternalServerError)
		render.JSON(w, r, returnError)
		return
	}

	// Verify the post belongs to the requester
	_, claims, _ := jwtauth.FromContext(r.Context())
	username := claims["username"].(string)
	if username != post.Author {
		w.WriteHeader(http.StatusUnauthorized)
		return
	}
	// update the post struct
	err = json.NewDecoder(r.Body).Decode(&post)
	s := `
    UPDATE posts SET
    title = $1,
    content = $2,
    updated = $3,
    update_time = $4
    WHERE id = $5`
	// write the row update
	_, err = DB.Exec(s, post.Title, post.Content, true, time.Now().UTC(), post.ID)
	if err != nil {
		returnError.Message = "something is super broken..."
		w.WriteHeader(http.StatusInternalServerError)
		render.JSON(w, r, returnError)
		return
	}
	returnSuccess := ReturnSuccess{Message: "post updated", ID: post.ID}
	w.WriteHeader(http.StatusOK)
	render.JSON(w, r, returnSuccess)
	return
}

func getBlogPosts(w http.ResponseWriter, r *http.Request) {
	return
}

func getBlogPostBySlug(w http.ResponseWriter, r *http.Request) {
	returnError := ReturnError{}
	slug := chi.URLParam(r, "slug")
	result := DB.QueryRow("SELECT id, title, slug, author, content, date, updated, update_time FROM posts WHERE slug=$1", slug)
	post := BlogPost{}
	err := result.Scan(&post.ID, &post.Title, &post.Slug, &post.Author, &post.Content, &post.DatePublished, &post.Updated, &post.UpdateTime)
	if err != nil {
		fmt.Println(err)
		returnError.Message = "post not found"
		w.WriteHeader(http.StatusBadRequest)
		render.JSON(w, r, returnError)
		return
	}
	w.WriteHeader(http.StatusOK)
	render.JSON(w, r, post)
	return
}

func getBlogPostById(w http.ResponseWriter, r *http.Request) {
	returnError := ReturnError{}
	id := chi.URLParam(r, "id")
	result := DB.QueryRow("SELECT id, title, slug, author, content, date, updated, update_time FROM posts WHERE id=$1", id)
	post := BlogPost{}
	err := result.Scan(&post.ID, &post.Title, &post.Slug, &post.Author, &post.Content, &post.DatePublished, &post.Updated, &post.UpdateTime)
	if err != nil {
		fmt.Println(err)
		returnError.Message = "post not found"
		w.WriteHeader(http.StatusBadRequest)
		render.JSON(w, r, returnError)
		return
	}
	w.WriteHeader(http.StatusOK)
	render.JSON(w, r, post)
	return
}

func getBlogPostsByTag(w http.ResponseWriter, r *http.Request) {
	return
}

func getBlogPostsByAuthor(w http.ResponseWriter, r *http.Request) {
	return
}

func getRssFeed(w http.ResponseWriter, r *http.Request) {
	return
}