class ToppagesController < ApplicationController
  def index
    if logged_in?
      @user = current_user
      @post = current_user.posts.build  # form_for 用
      @posts = current_user.feed_posts.order('created_at DESC').page(params[:page])
      @comments = @post.comments.order('created_at DESC').page(params[:page])
    end
  end
end

class CommentsController < ApplicationController
  #before_action :set_comment, only: [:new,:create, :destroy]
  before_action :require_user_logged_in

  def create
    @post = Post.find(params[:post_id])
    @comment = @post.comments.build(comment_params)
    @comment.user_id = current_user.id
    #@comment = current_user.posts.comments.build(comment_params)
    #@comment = Comment.create(text: comment_params[:text], post_id: comment_params[:post_id], user_id: current_user.id)
    if @comment.save
      flash[:success] = "コメントしました。"
      #redirect_to "/posts/#{@comment.post.id}"
      #redirect_to post_comments_path(@post.id)
      #redirect_to :action =>"new"
      redirect_to root_url
    else
      @comments = @post.comments.order('created_at DESC').page(params[:page])
      flash.now[:danger] = 'コメントの投稿に失敗しました。'
      render 'toppages/index'
    end
  end

  def destroy
    @comment.destroy
    flash[:success] = 'コメントを削除しました。'
    redirect_back(fallback_location: root_path)
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_comment
      @post = Post.find(params[:post_id])
      @comment = @post.comments.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def comment_params
      params.require(:comment).permit(:user_id, :post_id, :content)
    end
end

class PostsController < ApplicationController
  before_action :require_user_logged_in
  before_action :correct_user, only: [:destroy]

  def index
    @comment = @post.comments.build(comment_params)
  end

  def show
    @post = Post.includes(:user).find(params[:id])
  end

  def create
    @post = current_user.posts.build(post_params)
    if @post.save
      flash[:success] = 'メッセージを投稿しました。'
      redirect_to root_url
    else
      @posts = current_user.feed_posts.order('created_at DESC').page(params[:page])
      flash.now[:danger] = 'メッセージの投稿に失敗しました。'
      render 'toppages/index'
    end
  end

  def destroy
    @post.destroy
    flash[:success] = 'メッセージを削除しました。'
    redirect_back(fallback_location: root_path)
  end

  private

  def post_params
    params.require(:post).permit(:picture, :content)
  end

  def correct_user
    @post = current_user.posts.find_by(id: params[:id])
    unless @post
      redirect_to root_url
    end
  end
end

<ul class="media-list">
  <% @comments.each do |comment| %>
    <div class="name2">投稿者:<%= link_to comment.user, "/users/#{comment.user_id}" %>&nbsp;&nbsp;投稿日時:<%= comment.created_at.strftime("%Y-%m-%d %H:%M:%S") %></div>
    <div class="name2"><%= comment.content %></div>
    <div>
      <% if current_user == comment.user %>
        <%= link_to "削除", comment, method: :delete, data: { confirm: "本当に削除してよろしいですか?" }, class: 'btn btn-danger btn-sm' %>
      <% end %>
    </div>
  <% end %>
  <%= paginate comments %>

<ul class="media-list">
  <% posts.each do |post| %>
    <% user = post.user %>
    <li class="media">
      <div class="media-left">
        <img class="media-object img-rounded" src="<%= gravatar_url(user, options = { size: 50 }) %>" alt="">
      </div>
      <div class="media-body">
        <div>
          <%= link_to user.name, user_path(user) %> <span class="text-muted">posted at <%= post.created_at %></span>
        </div>
        <div>
          <p><%= image_tag post.picture,:size =>"280x210" %></p>
          <p><%= post.content %></p>
          <%= render 'comments/comments', comments: @comments %>
          <br/>
          <% if current_user %>
            <%= form_for [post, Comment.new] do |form| %>
              <%= form.text_area :content, cols: "30", placeholder: "コメントする", rows: "2" %>
              <%= form.submit "コメントの投稿" %>
            <% end %>
          <% end %>
        </div>
        <div>
          <% if current_user == post.user %>
            <%= link_to "削除", post, method: :delete, data: { confirm: "本当に削除してよろしいですか?" }, class: 'btn btn-danger btn-sm' %>
          <% end %>
        </div>
      </div>
    </li>
  <% end %>
  <%= paginate posts %>
</ul>

<% content_for :cover do %>
  <% if logged_in? %>
    <div class="row">
      <aside class="col-md-4">
        <%= form_for(@post, html: {multipart: true}) do |f| %>
          <div class="form-group">
            <%= f.label :picture %>
            <%= f.file_field :picture %><br />
            <%= f.text_area :content, class: 'form-control', rows: 5 %>
          </div>
          <%= f.submit '投稿', class: 'btn btn-primary btn-md' %>
        <% end %>
      </aside>
      <div class="col-xs-8">
        <%= render 'posts/posts', posts: @posts %>
      </div>
    </div>
  <% else %>
    <div class="cover">
      <div class="cover-inner">
        <div class="cover-contents">
          <h1>毎日のつながりは、ここから始まる</h1>>
          <%= link_to 'まずは会員登録から', signup_path, class: 'btn btn-success btn-md' %>
          <%= link_to '会員の方はこちら', login_path, class: 'btn btn-success btn-md' %>
        </div>
      </div>
    </div>
  <% end %>
<% end %>

@comment = @post.comments.build
@comments = @post.comments.order('created_at DESC').page(params[:page])