use std::{
    error::Error,
    fs::{self, OpenOptions},
    io::Write,
    path::Path,
    time,
};

use lemmy_api_common::{
    community::{ListCommunities, ListCommunitiesResponse},
    post::CreatePost,
    sensitive::Sensitive,
};
use lemmy_db_schema::{
    newtypes::{CommunityId, LanguageId, PostId},
    ListingType,
};
use serde_derive::{Deserialize, Serialize};
use tokio::time::sleep;
use url::Url;

use crate::CLIENT;

macro_rules! pub_struct {
    ($name:ident {$($field:ident: $t:ty,)*}) => {
        #[derive(Serialize, Deserialize, Clone, PartialEq)]
        pub(crate) struct $name {
            $(pub(crate) $field: $t), *
        }
    }
}

// Secrets structs
pub_struct!(Secrets {
    lemmy: LemmyLogin,
    reddit: RedditLogin,
});

impl Secrets {
    pub(crate) fn init() -> Secrets {
        let file_contents = match fs::read_to_string("secrets.json") {
            Ok(data) => data,
            Err(e) => panic!("ERROR: secrets.json could not be read:\n\n{:#?}", e),
        };
        let config_parse: Secrets = match serde_json::from_str(&file_contents) {
            Ok(data) => data,
            Err(e) => panic!("ERROR: secrets.json could not be parsed:\n\n{:#?}", e),
        };

        return config_parse;
    }
}

#[derive(Serialize, Deserialize, Clone, PartialEq)]
pub(crate) struct LemmyLogin {
    pub(crate) username: String,
    password: String,
}

impl LemmyLogin {
    pub(crate) fn get_username(&self) -> Sensitive<String> {
        return Sensitive::new(self.username.clone());
    }

    pub(crate) fn get_password(&self) -> Sensitive<String> {
        return Sensitive::new(self.password.clone());
    }
}

#[derive(Serialize, Deserialize, Clone, PartialEq)]
pub(crate) struct RedditLogin {
    pub(crate) app_id: String,
    app_secret: String,
    refresh_token: String,
    redirect_uri: String,
}

// Config structs
pub_struct!(Config {
    instance: String,
    reddit_config: RedditConfig,
    feeds: Vec<FeedSetting>,
});

impl Config {
    pub(crate) fn init() -> Config {
        let file_contents = match fs::read_to_string("config.json") {
            Ok(data) => data,
            Err(e) => panic!("ERROR: config.json could not be read:\n\n{:#?}", e),
        };
        let config_parse: Config = match serde_json::from_str(&file_contents) {
            Ok(data) => data,
            Err(e) => panic!("ERROR: config.json could not be parsed:\n\n{:#?}", e),
        };

        return config_parse;
    }

    pub(crate) fn load(&mut self) {
        let file_contents = match fs::read_to_string("config.json") {
            Ok(data) => data,
            Err(e) => panic!("ERROR: config.json could not be read:\n\n{:#?}", e),
        };
        let config_parse: Config = match serde_json::from_str(&file_contents) {
            Ok(data) => data,
            Err(e) => panic!("ERROR: config.json could not be parsed:\n\n{:#?}", e),
        };

        self.feeds = config_parse.feeds;
        self.instance = config_parse.instance;
        self.reddit_config = config_parse.reddit_config;
    }

    pub(crate) async fn check_feeds(
        &mut self,
        post_history: &mut Vec<PrevPost>,
        community_ids: &CommunitiesVector,
        auth: &Sensitive<String>,
    ) -> Result<Vec<(CreatePost, (Option<usize>, usize, String))>, Box<dyn Error>> {
        let mut post_queue: Vec<(CreatePost, (Option<usize>, usize, String))> = vec![];

        let mut i = 0;
        while i < self.feeds.len() {
            let feed = &self.feeds[i];

            let res = CLIENT
                .get(feed.feed_url.clone())
                .send()
                .await?
                .text()
                .await?;

            let data: FeedData = serde_json::from_str(&res).unwrap();

            let mut prev_post_idx: Option<usize> = None;
            let mut do_post = true;
            post_history.iter().enumerate().for_each(|(idx, post)| {
                if &post.last_post_url == &data.items[0].url {
                    do_post = false;
                } else if &post.title == &data.title {
                    prev_post_idx = Some(idx);
                }
            });

            if do_post {
                let item = &data.items[0];
                let new_post = CreatePost {
                name: item.title.clone(),
                community_id: community_ids.find(&feed.communities.chapter),
                url: Some(Url::parse(&item.url).unwrap()),
                body: Some(
                    "[Reddit](https://reddit.com/r/HonzukinoGekokujou)\n\n[Discord](https://discord.com/invite/fGefmzu)".into(),
                ),
                honeypot: None,
                nsfw: Some(false),
                language_id: Some(LanguageId(37)), // TODO get this id once every few hours per API request, the ordering of IDs suggests that the EN Id might change in the future
                auth: auth.clone(),
            };

                let prev_data = (prev_post_idx, feed.id, data.title);

                post_queue.push((new_post, prev_data));
            }
            sleep(time::Duration::from_millis(100)).await; // Should prevent dos-ing J-Novel servers
            i += 1;
        }

        return Ok(post_queue);
    }
}

pub_struct!(RedditConfig {
    user_agent: String,
    subreddit: String,
});

pub_struct!(FeedSetting {
    id: usize,
    feed_url: String,
    communities: FeedCommunities,
    reddit: FeedRedditSettings,
});

pub_struct!(FeedCommunities {
    chapter: LemmyCommunities,
    volume: LemmyCommunities,
});

#[derive(Serialize, Deserialize, Clone, PartialEq, strum_macros::Display)]
#[allow(non_camel_case_types)]
pub(crate) enum LemmyCommunities {
    aobwebnovel,
    aobprepub,
    aoblightnovel,
    aobmanga,
    metadiscussions,
}

pub_struct!(FeedRedditSettings {
    enabled: bool,
    flair: String,
});

// Posts structs
pub_struct!(PrevPost {
    id: usize,
    post_id: PostId,
    title: String,
    last_post_url: String,
});

impl PrevPost {
    pub(crate) fn load() -> Vec<PrevPost> {
        let history;

        if Path::new("posts.json").exists() {
            let file_contents = match fs::read_to_string("posts.json") {
                Ok(data) => data,
                Err(e) => panic!("ERROR: posts.json could not be read:\n\n{:#?}", e),
            };

            if file_contents.len() > 0 {
                let history_parse: Vec<PrevPost> = match serde_json::from_str(&file_contents) {
                    Ok(data) => data,
                    Err(e) => panic!("ERROR: posts.json could not be parsed:\n\n{:#?}", e),
                };
                history = history_parse;
            } else {
                history = [].to_vec()
            }
        } else {
            let _ = fs::File::create("posts.json");
            history = [].to_vec()
        }

        return history;
    }

    pub(crate) fn save(data: &Vec<PrevPost>) {
        let mut file = OpenOptions::new()
            .read(true)
            .write(true)
            .create(true)
            .open("posts.json")
            .unwrap();

        let json_data = serde_json::to_string_pretty(&data).unwrap();

        write!(&mut file, "{}", json_data).unwrap();
    }
}

// RSS Feed Structs
pub_struct!(FeedData {
    version: String,
    title: String,
    home_page_url: String,
    description: String,
    author: FeedAuthor,
    items: Vec<FeedEntry>,
});

pub_struct!(FeedAuthor { name: String, });

pub_struct!(FeedEntry {
    id: String,
    url: String,
    title: String,
    summary: String,
    image: Option<String>,
    date_published: String,
});

// Bot Helper Structs
pub_struct!(CommunitiesVector {
    ids: Vec<(CommunityId, String)>,
});

impl CommunitiesVector {
    pub(crate) fn new() -> CommunitiesVector {
        CommunitiesVector { ids: vec![] }
    }

    #[warn(unused_results)]
    pub(crate) async fn load(
        &mut self,
        auth: &Sensitive<String>,
        base: &String,
    ) -> Result<(), Box<dyn Error>> {
        let params = ListCommunities {
            auth: Some(auth.clone()),
            type_: Some(ListingType::Local),
            ..Default::default()
        };

        let res = CLIENT
            .get(base.clone() + "/api/v3/community/list")
            .query(&params)
            .send()
            .await?
            .text()
            .await?;

        let site_data: ListCommunitiesResponse = serde_json::from_str(&res).unwrap();

        let mut ids = [].to_vec();

        site_data.communities.iter().for_each(|entry| {
            let new_id = (entry.community.id, entry.community.name.clone());
            ids.push(new_id);
        });

        self.ids = ids;
        return Ok(());
    }

    pub(crate) fn find(&self, name: &LemmyCommunities) -> CommunityId {
        let mut ret_id = CommunityId(0);

        self.ids.iter().for_each(|id| {
            let id_name = &id.1;
            if &name.to_string() == id_name {
                ret_id = id.0;
            }
        });
        return ret_id;
    }
}