use oiseau::cache::Cache;
use crate::model::stacks::StackPrivacy;
use crate::model::{Error, Result, auth::User, stacks::StackBlock, permissions::FinePermission};
use crate::{auto_method, DataManager};

use oiseau::PostgresRow;

use oiseau::{execute, get, params, query_row, query_rows};

impl DataManager {
    /// Get a [`StackBlock`] from an SQL row.
    pub(crate) fn get_stackblock_from_row(x: &PostgresRow) -> StackBlock {
        StackBlock {
            id: get!(x->0(i64)) as usize,
            created: get!(x->1(i64)) as usize,
            initiator: get!(x->2(i64)) as usize,
            stack: get!(x->3(i64)) as usize,
        }
    }

    auto_method!(get_stackblock_by_id()@get_stackblock_from_row -> "SELECT * FROM stackblocks WHERE id = $1" --name="stack block" --returns=StackBlock --cache-key-tmpl="atto.stackblock:{}");

    pub async fn get_user_stack_blocked_users(&self, user_id: usize) -> Vec<usize> {
        let mut stack_block_users = Vec::new();

        for block in self.get_stackblocks_by_initiator(user_id).await {
            for user in match self.fill_stackblocks_receivers(block.stack).await {
                Ok(ul) => ul,
                Err(_) => continue,
            } {
                stack_block_users.push(user);
            }
        }

        stack_block_users
    }

    /// Fill a vector of stack blocks with their receivers (by pulling the stack).
    pub async fn fill_stackblocks_receivers(&self, stack: usize) -> Result<Vec<usize>> {
        let stack = self.get_stack_by_id(stack).await?;
        let mut out = Vec::new();

        for block in stack.users {
            out.push(block);
        }

        Ok(out)
    }

    /// Get all stack blocks created by the given `initiator`.
    pub async fn get_stackblocks_by_initiator(&self, initiator: usize) -> Vec<StackBlock> {
        let conn = match self.0.connect().await {
            Ok(c) => c,
            Err(_) => return Vec::new(),
        };

        let res = query_rows!(
            &conn,
            "SELECT * FROM stackblocks WHERE initiator = $1",
            &[&(initiator as i64)],
            |x| { Self::get_stackblock_from_row(x) }
        );

        if res.is_err() {
            return Vec::new();
        }

        // make sure all stacks still exist
        let list = res.unwrap();

        for block in &list {
            if self.get_stack_by_id(block.stack).await.is_err() {
                if self.delete_stackblock_sudo(block.id).await.is_err() {
                    continue;
                }
            }
        }

        // return
        list
    }

    /// Get a stack block by `initiator` and `stack` (in that order).
    pub async fn get_stackblock_by_initiator_stack(
        &self,
        initiator: usize,
        stack: usize,
    ) -> Result<StackBlock> {
        let conn = match self.0.connect().await {
            Ok(c) => c,
            Err(e) => return Err(Error::DatabaseConnection(e.to_string())),
        };

        let res = query_row!(
            &conn,
            "SELECT * FROM stackblocks WHERE initiator = $1 AND stack = $2",
            &[&(initiator as i64), &(stack as i64)],
            |x| { Ok(Self::get_stackblock_from_row(x)) }
        );

        if res.is_err() {
            return Err(Error::GeneralNotFound("stack block".to_string()));
        }

        Ok(res.unwrap())
    }

    const MAXIMUM_FREE_STACKBLOCKS: usize = 5;
    const MAXIMUM_SUPPORTER_STACKBLOCKS: usize = 10;

    /// Create a new stack block in the database.
    ///
    /// # Arguments
    /// * `data` - a mock [`StackBlock`] object to insert
    pub async fn create_stackblock(&self, data: StackBlock) -> Result<()> {
        let initiator = self.get_user_by_id(data.initiator).await?;

        // check number of stackblocks
        let stackblocks = self.get_stackblocks_by_initiator(data.initiator).await;

        if !initiator.permissions.check(FinePermission::SUPPORTER) {
            if stackblocks.len() >= Self::MAXIMUM_FREE_STACKBLOCKS {
                return Err(Error::MiscError(
                    "You already have the maximum number of stack blocks you can have".to_string(),
                ));
            }
        } else {
            if stackblocks.len() >= Self::MAXIMUM_SUPPORTER_STACKBLOCKS {
                return Err(Error::MiscError(
                    "You already have the maximum number of stack blocks you can have".to_string(),
                ));
            }
        }

        // ...
        let stack = self.get_stack_by_id(data.stack).await?;

        if initiator.id != stack.owner
            && stack.privacy == StackPrivacy::Private
            && !initiator.permissions.check(FinePermission::MANAGE_STACKS)
        {
            return Err(Error::NotAllowed);
        }

        // ...
        let conn = match self.0.connect().await {
            Ok(c) => c,
            Err(e) => return Err(Error::DatabaseConnection(e.to_string())),
        };

        let res = execute!(
            &conn,
            "INSERT INTO stackblocks VALUES ($1, $2, $3, $4)",
            params![
                &(data.id as i64),
                &(data.created as i64),
                &(data.initiator as i64),
                &(data.stack as i64)
            ]
        );

        if let Err(e) = res {
            return Err(Error::DatabaseError(e.to_string()));
        }

        // unfollow/remove follower
        for user in stack.users {
            if let Ok(f) = self
                .get_userfollow_by_initiator_receiver(data.initiator, user)
                .await
            {
                self.delete_userfollow_sudo(f.id, data.initiator).await?;
            }

            if let Ok(f) = self
                .get_userfollow_by_receiver_initiator(data.initiator, user)
                .await
            {
                self.delete_userfollow_sudo(f.id, data.initiator).await?;
            }
        }

        // return
        Ok(())
    }

    pub async fn delete_stackblock(&self, id: usize, user: User) -> Result<()> {
        let block = self.get_stackblock_by_id(id).await?;

        if user.id != block.initiator {
            // only the initiator (or moderators) can delete stack blocks!
            if !user.permissions.check(FinePermission::MANAGE_FOLLOWS) {
                return Err(Error::NotAllowed);
            }
        }

        let conn = match self.0.connect().await {
            Ok(c) => c,
            Err(e) => return Err(Error::DatabaseConnection(e.to_string())),
        };

        let res = execute!(
            &conn,
            "DELETE FROM stackblocks WHERE id = $1",
            &[&(id as i64)]
        );

        if let Err(e) = res {
            return Err(Error::DatabaseError(e.to_string()));
        }

        self.0.1.remove(format!("atto.stackblock:{}", id)).await;

        // return
        Ok(())
    }

    pub async fn delete_stackblock_sudo(&self, id: usize) -> Result<()> {
        let conn = match self.0.connect().await {
            Ok(c) => c,
            Err(e) => return Err(Error::DatabaseConnection(e.to_string())),
        };

        let res = execute!(
            &conn,
            "DELETE FROM stackblocks WHERE id = $1",
            &[&(id as i64)]
        );

        if let Err(e) = res {
            return Err(Error::DatabaseError(e.to_string()));
        }

        self.0.1.remove(format!("atto.stackblock:{}", id)).await;

        // return
        Ok(())
    }
}