//! # Posts controller
//!
//! @author Pierre Hubert

use crate::api_data::post_api::PostAPI;
use crate::api_data::res_create_post::ResCreatePost;
use crate::constants::{PATH_POST_IMAGES, PATH_POST_PDF};
use crate::controllers::routes::RequestResult;
use crate::data::error::{ExecError, ResultBoxError};
use crate::data::group::GroupAccessLevel;
use crate::data::http_request_handler::HttpRequestHandler;
use crate::data::new_survey::NewSurvey;
use crate::data::post::{Post, PostAccessLevel, PostFile, PostKind, PostPageKind, PostVisibilityLevel, PostWebLink};
use crate::helpers::{groups_helper, posts_helper, survey_helper, user_helper};
use crate::utils::date_utils::time;
use crate::utils::string_utils::{check_string_before_insert, check_youtube_id};
use crate::utils::user_data_utils::user_data_path;

impl PostFile {
    /// Initialize a `PostFile` instance based on a file that have just been created
    pub fn new_from_created_file(path: &str) -> ResultBoxError<PostFile> {
        let data = std::fs::metadata(user_data_path(path.as_ref()))?;
        Ok(PostFile {
            path: path.to_string(),
            size: data.len() as usize,
            file_type: mime_guess::from_path(path)
                .first()
                .map(|m| format!("{}/{}", m.type_(), m.subtype())),
        })
    }
}

/// Get the list of posts of a user
pub fn get_list_user(r: &mut HttpRequestHandler) -> RequestResult {
    let user_id = r.post_user_id("userID")?;
    let start_from = r.post_u64_opt("startFrom", 0)?;

    if !user_helper::can_see_user_page(r.user_id_ref()?, &user_id)? {
        r.forbidden("You are not allowed to access this user posts !".to_string())?;
    }

    let posts = posts_helper::PostsQuery::new(r.user_id_opt())
        .set_start_from(start_from)
        .get_user(&user_id)?;

    r.set_response(PostAPI::for_list(&posts, r.user_id_opt())?)
}

/// Get the list of posts of a group
pub fn get_list_group(r: &mut HttpRequestHandler) -> RequestResult {
    let group_id = r.post_group_id_with_access("groupID", GroupAccessLevel::VIEW_ACCESS)?;
    let start_from = r.post_u64_opt("startFrom", 0)?;

    let posts = posts_helper::PostsQuery::new(r.user_id_opt())
        .set_start_from(start_from)
        .get_group(&group_id)?;

    r.set_response(PostAPI::for_list(&posts, r.user_id_opt())?)
}

/// Get the latest posts of a group
pub fn get_latest(r: &mut HttpRequestHandler) -> RequestResult {
    let start_from = r.post_u64_opt("startFrom", 0)?;
    let include_groups = r.post_bool_opt("include_groups", false);

    let posts = posts_helper::PostsQuery::new(r.user_id_opt())
        .set_start_from(start_from)
        .get_latest(include_groups)?;

    r.set_response(PostAPI::for_list(&posts, r.user_id_opt())?)
}

/// Get information about a single post
pub fn get_single(r: &mut HttpRequestHandler) -> RequestResult {
    let post = r.post_post_with_access("postID", PostAccessLevel::BASIC_ACCESS)?;

    r.set_response(PostAPI::new(&post, &r.user_id_opt())?)
}

/// Create a new post
pub fn create_post(r: &mut HttpRequestHandler) -> RequestResult {
    // Process page target
    let target_page = match r.post_string("kind-page")?.as_str() {
        "user" => {
            let user_id = r.post_user_id("kind-id")?;

            if !user_helper::can_create_posts(r.user_id_ref()?, &user_id)? {
                r.forbidden("You are not allowed to create posts on this page!".to_string())?;
            }

            PostPageKind::PAGE_KIND_USER(user_id)
        }

        "group" => {
            let group_id = r.post_group_id_with_access("kind-id", GroupAccessLevel::MEMBER_ACCESS)?;

            if !groups_helper::can_user_create_posts(&group_id, r.user_id_ref()?)? {
                r.forbidden("You are not allowed to create posts on this group!".to_string())?;
            }

            PostPageKind::PAGE_KIND_GROUP(group_id)
        }

        _ => {
            r.not_found("Unsupported target page type!".to_string())?;
            unreachable!();
        }
    };

    // Start to create post
    let mut post = Post {
        id: 0,
        user_id: r.user_id()?,
        time_create: time(),
        target_page,
        content: Some(r.post_string_opt("content", 0, false)?),
        visibility: PostVisibilityLevel::from_api(&r.post_string("visibility")?),
        kind: PostKind::POST_KIND_TEXT,
    };

    let mut new_survey = None;

    // Handle different post types
    post.kind = match r.post_string("kind")?.as_str() {

        // Text posts
        "text" => {
            if !check_string_before_insert(post.content.as_ref().unwrap_or(&String::new())) {
                r.forbidden("Specified post content is invalid!".to_string())?;
            }

            PostKind::POST_KIND_TEXT
        }


        // Image post
        "image" => {
            if !r.has_file("image") {
                r.bad_request("An error occured while receiving the image!".to_string())?;
            }

            let path = r.save_post_image("image", PATH_POST_IMAGES, 2000, 2000)?;

            PostKind::POST_KIND_IMAGE(PostFile::new_from_created_file(&path)?)
        }

        // YouTube posts
        "youtube" => {
            let youtube = r.post_string("youtube_id")?;

            if !check_youtube_id(&youtube) {
                r.bad_request("Invalid YouTube ID!".to_string())?;
            }

            PostKind::POST_KIND_YOUTUBE(youtube)
        }

        // Movies posts
        "movie" => {
            let movie_id = r.post_movie_id("movieID")?;

            PostKind::POST_KIND_MOVIE(movie_id)
        }

        // Weblink posts
        "weblink" => {
            let url = r.post_url_opt("url", true)?
                .ok_or(ExecError::new("Missing url!"))?;

            // For now, for safety, we do not fetch page content
            // But this might change in the future
            PostKind::POST_KIND_WEBLINK(PostWebLink {
                url,
                title: None,
                description: None,
                image: None,
            })
        }

        "pdf" => {
            if !r.has_file("pdf") {
                r.bad_request("Missing PDF in 'pdf'!".to_string())?;
            }

            let file = r.save_post_pdf("pdf", PATH_POST_PDF)?;

            PostKind::POST_KIND_PDF(PostFile::new_from_created_file(&file)?)
        }

        "countdown" => {
            let time_end = r.post_u64("time-end")?;

            if time_end < time() {
                r.bad_request("You can not create countdown timer for past events!".to_string())?;
            }

            PostKind::POST_KIND_COUNTDOWN(time_end)
        }

        "survey" => {
            let survey = NewSurvey {
                post_id: 0,
                user_id: r.user_id()?,
                question: r.post_string("question")?,
                choices: r.post_string("answers")?
                    .split("<>")
                    .filter(|a| a.len() > 0)
                    .map(|a| a.to_string())
                    .collect(),
                allow_new_choices: r.post_bool_opt("allowNewAnswers", false),
            };

            if survey.choices.len() < 2 {
                r.bad_request("A survey must have at least two choices!".to_string())?;
            }

            new_survey = Some(survey);
            PostKind::POST_KIND_SURVEY
        }

        _ => {
            r.internal_error(ExecError::boxed_new("Unsupported kind of post!"))?;
            unreachable!();
        }
    };

    // Create the post
    let post_id = posts_helper::create(&post)?;

    // Create associated survey, if required
    if let Some(mut survey) = new_survey {
        survey.post_id = post_id;
        survey_helper::create(&survey)?;
    }

    // TODO : create a notification
    r.set_response(ResCreatePost::new(post_id))
}

/// Change the visibility level of a post
pub fn set_visibility_level(r: &mut HttpRequestHandler) -> RequestResult {
    let post = r.post_post_with_access("postID", PostAccessLevel::FULL_ACCESS)?;
    let new_visibility = PostVisibilityLevel::from_api(&r.post_string("new_level")?);

    posts_helper::set_level(post.id, new_visibility)?;

    // TODO : Depending on new level, delete (or not) notifications about the post

    r.success("Visibility level updated")
}

/// Update the content of a post
pub fn update_content(r: &mut HttpRequestHandler) -> RequestResult {
    let post = r.post_post_with_access("postID", PostAccessLevel::FULL_ACCESS)?;
    let new_content = r.post_content("new_content", 2, true)?;

    posts_helper::set_content(post.id, &new_content)?;

    // TODO : Delete the notifications targeting the current user about this post

    r.success("Content updated")
}

/// Delete a post
pub fn delete(r: &mut HttpRequestHandler) -> RequestResult {
    r.success("Implement me")
}