use crate::models::service::ServiceGroup;
use bitflags::bitflags;
use j_db::database::Database;
use j_db::model::JdbModel;
use poise::serenity_prelude::UserId;
use serde::{Deserialize, Serialize};
use std::collections::{HashMap, HashSet};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct User {
    pub discord_uuid: UserId,
    id: Option<u64>,
}

impl User {
    pub fn new(discord_uuid: UserId) -> Self {
        Self {
            discord_uuid,
            id: None,
        }
    }

    pub fn find_user_by_id(
        db: &Database,
        uuid: UserId,
    ) -> Result<Option<User>, j_db::error::JDbError> {
        let user = db
            .filter(|_, user: &User| user.discord_uuid == uuid)?
            .next();

        Ok(user)
    }
}

impl j_db::model::JdbModel for User {
    fn id(&self) -> Option<u64> {
        self.id
    }

    fn set_id(&mut self, id: u64) {
        self.id = Some(id);
    }

    fn tree() -> String {
        "User".to_string()
    }
}

bitflags! {
    #[derive(Serialize, Deserialize, Copy, Debug, Clone, PartialEq)]
    pub struct Permissions: u32 {
        const Status    = 0b00001;
        const Start     = 0b00010;
        const Stop      = 0b00100;
        const Restart   = 0b01000;
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct UserGroup {
    pub name: String,
    pub description: String,
    pub members: HashSet<u64>,
    pub permissions: HashMap<u64, Permissions>,

    id: Option<u64>,
}

impl UserGroup {
    pub fn new(name: &str, description: &str) -> Self {
        Self {
            name: name.to_string(),
            description: description.to_string(),
            members: HashSet::new(),
            permissions: Default::default(),
            id: None,
        }
    }

    pub fn find_group_by_name(
        db: &Database,
        name: &str,
    ) -> Result<Option<Self>, j_db::error::JDbError> {
        let group = db
            .filter(|_, group: &UserGroup| group.name.eq_ignore_ascii_case(name))?
            .next();

        Ok(group)
    }

    pub fn add_user_to_group(
        db: &Database,
        group_name: &str,
        user_id: u64,
    ) -> Result<Self, j_db::error::JDbError> {
        let mut group =
            Self::find_group_by_name(db, group_name)?.ok_or(j_db::error::JDbError::NotFound)?;

        group.members.insert(user_id);

        let group = db.insert(group)?;

        Ok(group)
    }

    pub fn set_group_permission(
        db: &Database,
        group_name: &str,
        service_group: u64,
        permissions: Permissions,
    ) -> Result<Self, j_db::error::JDbError> {
        let mut group =
            Self::find_group_by_name(db, group_name)?.ok_or(j_db::error::JDbError::NotFound)?;

        group.permissions.insert(service_group, permissions);

        let group = db.insert(group)?;

        Ok(group)
    }

    pub fn get_user_groups(
        db: &Database,
        user: u64,
    ) -> Result<Vec<UserGroup>, j_db::error::JDbError> {
        Ok(db
            .filter(|_, group: &UserGroup| group.members.contains(&user))?
            .collect())
    }

    pub fn check_if_user_has_permission(
        db: &Database,
        user: u64,
        service: u64,
        permission: Permissions,
    ) -> Result<bool, j_db::error::JDbError> {
        let user_groups = Self::get_user_groups(db, user)?;
        let service_group = ServiceGroup::get_service_groups(db, service)?;

        Ok(Self::check_perm(permission, user_groups, service_group))
    }

    fn check_perm(
        permission: Permissions,
        user_groups: Vec<UserGroup>,
        service_group: Vec<ServiceGroup>,
    ) -> bool {
        let mut unified_permission_map: HashMap<u64, Permissions> = HashMap::new();

        for user_group in user_groups {
            for (group, permission) in user_group.permissions {
                #[allow(clippy::map_entry)]
                if unified_permission_map.contains_key(&group) {
                    let perm1 = unified_permission_map.get_mut(&group).unwrap();
                    *perm1 |= permission;
                } else {
                    unified_permission_map.insert(group, permission);
                }
            }
        }

        let service_group_ids: HashSet<u64> = service_group
            .iter()
            .map(|service_group| service_group.id().unwrap())
            .collect();

        for service_group in service_group_ids {
            let perm = unified_permission_map.get(&service_group);

            if let Some(perm) = perm {
                let check_perm = (permission & *perm) == permission;

                if check_perm {
                    return true;
                }
            }
        }

        false
    }
}

impl JdbModel for UserGroup {
    fn id(&self) -> Option<u64> {
        self.id
    }

    fn set_id(&mut self, id: u64) {
        self.id = Some(id);
    }

    fn tree() -> String {
        "UserGroup".to_string()
    }
}