use poise::CreateReply;
use reqwest::Client;
use serde::Deserialize;
use serenity::all::ButtonStyle;
use serenity::all::{
    ChannelId, CreateActionRow, CreateAllowedMentions, CreateButton, CreateMessage, ReactionType,
    User,
};
use sqlx::{query_as, Pool, Sqlite};
use std::ops::Add;

use crate::commands::command_helper::cooldown;
use crate::error::Error;
use crate::error::Error::Other;
use crate::Caches;
use crate::Context;

#[derive(Deserialize)]
struct Links {
    #[serde(rename = "DISCORD")]
    pub discord: Option<String>,
}

#[derive(Deserialize)]
struct SocialMedia {
    pub links: Option<Links>,
}

#[derive(Deserialize)]
struct HypixelPlayer {
    #[serde(rename = "socialMedia")]
    pub social_media: Option<SocialMedia>,
}

#[derive(Deserialize)]
struct HypixelResponse {
    #[serde(rename = "player")]
    pub player: HypixelPlayer,
}

#[derive(PartialEq, sqlx::FromRow)]
pub(crate) struct Uuid {
    pub(crate) uuid: String,
}

impl Uuid {
    fn get(&self) -> &str {
        self.uuid.as_str()
    }
    async fn for_ign(ign: &String, cli: &Client, c: &Caches) -> Result<Self, Error> {
        let uuid = crate::data::mojang::uuid(c, cli, ign.clone()).await?;
        Ok(Self { uuid })
    }

    async fn ign(&self, c: &Caches, cli: &Client) -> Result<String, Error> {
        let ign = crate::data::mojang::name(c, cli, self.uuid.clone()).await?;
        Ok(ign)
    }
}

#[derive(PartialEq)]
struct DiscordId {
    id: u64,
}

impl Uuid {
    async fn has_discord_user(&self, user: &User, client: &Client) -> Result<bool, Error> {
        let url: String = format!("https://api.hypixel.net/v2/player?uuid={}", self.uuid);
        let res: HypixelResponse = client
            .get(url)
            .send()
            .await?
            .error_for_status()?
            .json::<HypixelResponse>()
            .await?;
        let matches = res
            .player
            .social_media
            .and_then(|sm| sm.links)
            .and_then(|l| l.discord)
            .ok_or(Other(
                "The Hypixel profile has no Discord account linked. Please follow the steps in \
                 <#1256219552568840263>"
                    .to_string(),
            ))?
            == user.name;
        Ok(matches)
    }
}
impl<'a, R: sqlx::Row> sqlx::FromRow<'a, R> for DiscordId
where
    &'a ::std::primitive::str: sqlx::ColumnIndex<R>,
    i64: ::sqlx::decode::Decode<'a, R::Database>,
    i64: ::sqlx::types::Type<R::Database>,
{
    fn from_row(row: &'a R) -> sqlx::Result<Self> {
        let discord_id: i64 = row.try_get("discord_id")?;
        Ok(DiscordId {
            id: discord_id.cast_unsigned(),
        })
    }
}

pub(crate) struct Link {
    link_id: u16,
    discord_ids: Vec<DiscordId>,
    pub(crate) minecraft_accounts: Vec<Uuid>,
}

impl Link {
    fn new(link_id: u16) -> Self {
        Link {
            link_id,
            discord_ids: vec![],
            minecraft_accounts: vec![],
        }
    }
    async fn minecraft(mut self, pool: &Pool<Sqlite>) -> Result<Self, Error> {
        let link_id: i16 = self.link_id.cast_signed();
        self.minecraft_accounts = query_as(
            format!(
                "SELECT minecraft_uuid AS uuid FROM minecraft_links WHERE link_id = {link_id};"
            )
            .as_str(),
        )
        .fetch_all(pool)
        .await?;
        Ok(self)
    }
    async fn discord(mut self, pool: &Pool<Sqlite>) -> Result<Self, Error> {
        let link_id: i16 = self.link_id.cast_signed();
        self.discord_ids = query_as(
            format!("SELECT discord_id FROM discord_links WHERE link_id = {link_id};").as_str(),
        )
        .fetch_all(pool)
        .await?;
        Ok(self)
    }
}
#[poise::command(
    slash_command,
    subcommands("add", "list"),
    install_context = "User|Guild",
    interaction_context = "Guild|BotDm|PrivateChannel"
)]
pub(crate) async fn account(_ctx: Context<'_>) -> Result<(), Error> {
    // root of slash-commands is not invokable.
    unreachable!()
}

#[poise::command(slash_command, ephemeral = "false")]
/// Verify a Minecraft account on the Zombies MultiPlayer Discord.
pub(crate) async fn add(
    ctx: Context<'_>,
    #[description = "Minecraft username"]
    #[min_length = 2]
    #[max_length = 16]
    ign: String,
    #[description = "Discord User"] user: Option<User>,
    #[description = "admin-only"] force: Option<bool>,
) -> Result<(), Error> {
    ctx.defer().await?;
    let force: bool =
        force.unwrap_or(false) && ctx.framework().options.owners.contains(&ctx.author().id) && {
            let _ = user.as_ref().ok_or(Other(
                "Warning: attempted to run forced account add without specifying a target Discord \
                 account."
                    .to_string(),
            ))?;
            true
        };
    let user: User = user.unwrap_or(ctx.author().clone());
    let uuid: Uuid = Uuid::for_ign(&ign, &ctx.data().clients.general, &ctx.data().caches).await?;
    match force
        || uuid
            .has_discord_user(&user, &ctx.data().clients.hypixel_api_client)
            .await?
    {
        true => {
            let pool = &ctx.data().sqlite_pool;
            let status: &str = match link_id_from_minecraft(pool, uuid.get()).await {
                None => match link_id_from_discord(pool, user.id.get()).await {
                    None => {
                        let id = new_link_id(pool).await?;
                        sqlx::query(
                            format!(
                                "INSERT INTO discord_links VALUES ({}, {});",
                                id.inner,
                                user.id.get()
                            )
                            .as_str(),
                        )
                        .execute(pool)
                        .await?;
                        sqlx::query(
                            format!(
                                "INSERT INTO minecraft_links VALUES ({}, \"{}\");",
                                id.inner,
                                uuid.get()
                            )
                            .as_str(),
                        )
                        .execute(pool)
                        .await?;
                        "Linked your Discord and Minecraft account."
                    }
                    Some(dc_id) => {
                        sqlx::query(
                            format!(
                                "INSERT INTO minecraft_links VALUES ({}, \"{}\");",
                                dc_id.inner,
                                uuid.get()
                            )
                            .as_str(),
                        )
                        .execute(pool)
                        .await?;
                        "Your Discord account has previously had an account linked. Added the new \
                         link."
                    }
                },
                Some(mc_id) => match link_id_from_discord(pool, user.id.get()).await {
                    None => {
                        sqlx::query(
                            format!(
                                "INSERT INTO discord_links VALUES ({}, {});",
                                mc_id.inner,
                                user.id.get()
                            )
                            .as_str(),
                        )
                        .execute(pool)
                        .await?;
                        "Your Minecraft account has previously had an account linked. Added the \
                         new link."
                    }
                    Some(dc_id) => {
                        sqlx::query(
                            format!(
                                "UPDATE minecraft_links SET link_id = {} WHERE link_id = {};",
                                mc_id.inner, dc_id.inner
                            )
                            .as_str(),
                        )
                        .execute(pool)
                        .await?;
                        sqlx::query(
                            format!(
                                "UPDATE discord_links SET link_id = {} WHERE link_id = {};",
                                mc_id.inner, dc_id.inner
                            )
                            .as_str(),
                        )
                        .execute(pool)
                        .await?;
                        "Both your Discord and Minecraft account had linked accounts. Merged all \
                         account links."
                    }
                },
            };
            let s = format!(
                "Verification request for <@{}> with IGN `{}`",
                user.id.get(),
                ign
            );
            ChannelId::new(1257776992497959075)
                .send_message(
                    ctx,
                    CreateMessage::new()
                        .content(s)
                        .allowed_mentions(
                            CreateAllowedMentions::new().empty_roles().all_users(true),
                        )
                        .components(vec![CreateActionRow::Buttons(vec![
                            CreateButton::new("accept_verification")
                                .emoji(ReactionType::from('✅'))
                                .style(ButtonStyle::Secondary),
                            CreateButton::new("deny_verification")
                                .emoji(ReactionType::from('❌'))
                                .style(ButtonStyle::Secondary),
                            CreateButton::new("list_accounts")
                                .emoji(ReactionType::from('📜'))
                                .style(ButtonStyle::Primary),
                        ])]),
                )
                .await?;
            ctx.send(CreateReply::default().content(status)).await?;
            Ok(())
        }
        false => Err(Error::Other(format!(
            "The Discord account linked on Hypixel does not match the specified discord \
             account.\nPlease set your linked Discord account on Hypixel to `{}`.",
            user.name
        ))),
    }
}

#[poise::command(
    slash_command,
    ephemeral = "true",
    context_menu_command = "Account list"
)]
/// List a users linked minecraft Accounts.
pub(crate) async fn list(ctx: Context<'_>, user: User) -> Result<(), Error> {
    ctx.defer().await?;
    cooldown(&ctx, 600, 300)?;
    let pool: &Pool<Sqlite> = &ctx.data().sqlite_pool;
    let s: String =
        list_string(pool, &user, &ctx.data().caches, &ctx.data().clients.general).await?;
    ctx.send(
        CreateReply::default()
            .content(s)
            .allowed_mentions(CreateAllowedMentions::new().empty_roles().empty_users()),
    )
    .await?;
    Ok(())
}

pub(crate) async fn get_link(user: &User, pool: &Pool<Sqlite>) -> Result<Link, Error> {
    let link_id: u16 = link_id_from_discord(pool, user.id.get())
        .await
        .expect("This user has no linked accounts")
        .into();
    let link = Link::new(link_id)
        .minecraft(pool)
        .await?
        .discord(pool)
        .await?;
    Ok(link)
}

pub(crate) async fn list_string(
    pool: &Pool<Sqlite>,
    user: &User,
    c: &Caches,
    cli: &Client,
) -> Result<String, Error> {
    let link = get_link(user, pool).await?;
    let mut discord_list = String::from("### Discord:");
    for dc in link.discord_ids {
        discord_list.push_str(format!("\n- <@{}>", dc.id).as_str());
    }
    let mut minecraft_list = String::from("### Minecraft:");
    for mc in link.minecraft_accounts {
        minecraft_list.push_str(format!("\n- `{}`", mc.ign(c, cli).await?).as_str());
    }
    Ok(format!(
        "## Account list for member #{}:\n{}\n{}",
        link.link_id,
        discord_list.as_str(),
        minecraft_list.as_str()
    ))
}

#[poise::command(slash_command)]
pub(crate) async fn remove(_ctx: Context<'_>) -> Result<(), Error> {
    unimplemented!();
}

async fn link_id_from_minecraft(pool: &Pool<Sqlite>, minecraft_uuid: &str) -> Option<LinkId> {
    query_as(
        format!(
            "SELECT link_id FROM minecraft_links WHERE minecraft_uuid = \"{minecraft_uuid}\" \
             LIMIT 1;"
        )
        .as_str(),
    )
    .fetch_optional(pool)
    .await
    .expect("Database error: fetching link id by uuid")
}
async fn link_id_from_discord(pool: &Pool<Sqlite>, snowflake: u64) -> Option<LinkId> {
    query_as(
        format!(
            "SELECT link_id FROM discord_links WHERE discord_id = {} LIMIT 1;",
            snowflake.cast_signed()
        )
        .as_str(),
    )
    .fetch_optional(pool)
    .await
    .expect("Database error: fetching link_id for discord_id")
}

#[derive(sqlx::FromRow)]
struct LinkId {
    #[sqlx(rename = "link_id")]
    inner: i16,
}

impl From<u16> for LinkId {
    fn from(unsigned: u16) -> Self {
        Self {
            inner: unsigned.cast_signed(),
        }
    }
}

impl Into<u16> for LinkId {
    fn into(self) -> u16 {
        self.inner.cast_unsigned()
    }
}

impl Add<i16> for LinkId {
    type Output = LinkId;

    fn add(mut self, rhs: i16) -> Self::Output {
        self.inner += rhs;
        self
    }
}

async fn new_link_id(pool: &Pool<Sqlite>) -> Result<LinkId, Error> {
    let result: LinkId = query_as("SELECT MAX(link_id) AS link_id FROM minecraft_links;")
        .fetch_one(pool)
        .await?;
    Ok(result + 1)
}