use serde::{Deserialize, Serialize};
use tracing::instrument;

use crate::api::RegistrationRequet;
use crate::database::Database;
use crate::types::http::{ResponseCode, Result};

#[derive(Serialize, Deserialize, Debug)]
pub struct User {
    pub user_id: u64,
    pub firstname: String,
    pub lastname: String,
    pub email: String,
    pub password: String,
    pub gender: String,
    pub date: u64,
    pub day: u8,
    pub month: u8,
    pub year: u32,
}

pub const NO_RELATION: u8 = 0;
pub const FOLLOWING: u8 = 1;
pub const FOLLOWED: u8 = 2;

impl User {
    #[instrument(skip(db))]
    pub fn from_user_id(db: &Database, user_id: u64, hide_password: bool) -> Result<Self> {
        let Ok(Some(user)) = db.get_user_by_id(user_id, hide_password) else {
            return Err(ResponseCode::BadRequest.text("User does not exist"))
        };

        Ok(user)
    }

    #[instrument(skip(db))]
    pub fn from_user_ids(db: &Database, user_ids: Vec<u64>) -> Vec<Self> {
        user_ids
            .iter()
            .filter_map(|user_id| {
                let Ok(Some(user)) = db.get_user_by_id(*user_id, true) else {
                return None;
            };
                Some(user)
            })
            .collect()
    }

    #[instrument(skip(db))]
    pub fn from_user_page(db: &Database, page: u64) -> Result<Vec<Self>> {
        let Ok(users) = db.get_user_page(page, true) else {
            return Err(ResponseCode::BadRequest.text("Failed to fetch users"))
        };
        Ok(users)
    }

    #[instrument(skip(db))]
    pub fn from_email(db: &Database, email: &str) -> Result<Self> {
        let Ok(Some(user)) = db.get_user_by_email(email, false) else {
            return Err(ResponseCode::BadRequest.text("User does not exist"))
        };

        Ok(user)
    }

    #[instrument(skip(db))]
    pub fn from_password(db: &Database, password: &str) -> Result<Self> {
        let Ok(Some(user)) = db.get_user_by_password(password, true) else {
            return Err(ResponseCode::BadRequest.text("User does not exist"))
        };

        Ok(user)
    }

    #[instrument(skip(db))]
    pub fn reterieve_all(db: &Database) -> Result<Vec<Self>> {
        let Ok(users) = db.get_all_users() else {
            return Err(ResponseCode::InternalServerError.text("Failed to fetch users"))
        };
        Ok(users)
    }

    #[instrument(skip(db))]
    pub fn new(db: &Database, request: RegistrationRequet) -> Result<Self> {
        if Self::from_email(db, &request.email).is_ok() {
            return Err(ResponseCode::BadRequest
                .text(&format!("Email is already in use by {}", &request.email)));
        }

        if let Ok(user) = Self::from_password(db, &request.password) {
            return Err(ResponseCode::BadRequest
                .text(&format!("Password is already in use by {}", user.email)));
        }

        let Ok(user) = db.add_user(request) else {
            tracing::error!("Failed to create new user");
            return Err(ResponseCode::InternalServerError.text("Failed to create new uesr"))
        };

        Ok(user)
    }

    #[instrument(skip(db))]
    pub fn add_following(db: &Database, user_id_1: u64, user_id_2: u64) -> Result<()> {
        let Ok(followed) = db.set_following(user_id_1, user_id_2) else {
            return Err(ResponseCode::BadRequest.text("Failed to add follow status"))
        };

        if !followed {
            return Err(ResponseCode::InternalServerError.text("Failed to add follow status"));
        }

        Ok(())
    }

    #[instrument(skip(db))]
    pub fn remove_following(db: &Database, user_id_1: u64, user_id_2: u64) -> Result<()> {
        let Ok(followed) = db.remove_following(user_id_1, user_id_2) else {
            return Err(ResponseCode::BadRequest.text("Failed to remove follow status"))
        };

        if !followed {
            return Err(ResponseCode::InternalServerError.text("Failed to remove follow status"));
        }

        Ok(())
    }

    #[instrument(skip(db))]
    pub fn get_following(db: &Database, user_id_1: u64, user_id_2: u64) -> Result<u8> {
        let Ok(followed) = db.get_friend_status(user_id_1, user_id_2) else {
            return Err(ResponseCode::InternalServerError.text("Failed to get follow status"))
        };
        Ok(followed)
    }

    #[instrument(skip(db))]
    pub fn get_friends(db: &Database, user_id: u64) -> Result<(Vec<Self>, Vec<Self>, Vec<Self>)> {
        let Ok(friends) = db.get_friends(user_id) else {
            return Err(ResponseCode::InternalServerError.text("Failed to fetch friends"))
        };
        
        let Ok(followers) = db.get_followers(user_id) else {
            return Err(ResponseCode::InternalServerError.text("Failed to fetch friends"))
        };

        let Ok(following) = db.get_following(user_id) else {
            return Err(ResponseCode::InternalServerError.text("Failed to fetch friends"))
        };

        Ok((friends, followers, following))
    }
}