use crate::domain::{self, checker, config};
use crate::origin;
use std::error::Error;

#[derive(thiserror::Error, Debug)]
pub enum GetConfigError {
    #[error("not found")]
    NotFound,

    #[error(transparent)]
    Unexpected(Box<dyn Error>),
}

impl From<config::GetError> for GetConfigError {
    fn from(e: config::GetError) -> GetConfigError {
        match e {
            config::GetError::NotFound => GetConfigError::NotFound,
            config::GetError::Unexpected(e) => GetConfigError::Unexpected(e),
        }
    }
}

#[derive(thiserror::Error, Debug)]
pub enum GetOriginError {
    #[error("not found")]
    NotFound,

    #[error(transparent)]
    Unexpected(Box<dyn Error>),
}

impl From<config::GetError> for GetOriginError {
    fn from(e: config::GetError) -> GetOriginError {
        match e {
            config::GetError::NotFound => GetOriginError::NotFound,
            config::GetError::Unexpected(e) => GetOriginError::Unexpected(e),
        }
    }
}

#[derive(thiserror::Error, Debug)]
pub enum SyncError {
    #[error("not found")]
    NotFound,

    #[error("already in progress")]
    AlreadyInProgress,

    #[error(transparent)]
    Unexpected(Box<dyn Error>),
}

impl From<config::GetError> for SyncError {
    fn from(e: config::GetError) -> SyncError {
        match e {
            config::GetError::NotFound => SyncError::NotFound,
            config::GetError::Unexpected(e) => SyncError::Unexpected(e),
        }
    }
}

#[derive(thiserror::Error, Debug)]
pub enum SyncWithConfigError {
    #[error("invalid url")]
    InvalidURL,

    #[error("invalid branch name")]
    InvalidBranchName,

    #[error("already in progress")]
    AlreadyInProgress,

    #[error("target CNAME not set")]
    TargetCNAMENotSet,

    #[error("challenge token not set")]
    ChallengeTokenNotSet,

    #[error(transparent)]
    Unexpected(Box<dyn Error>),
}

impl From<origin::store::SyncError> for SyncWithConfigError {
    fn from(e: origin::store::SyncError) -> SyncWithConfigError {
        match e {
            origin::store::SyncError::InvalidURL => SyncWithConfigError::InvalidURL,
            origin::store::SyncError::InvalidBranchName => SyncWithConfigError::InvalidBranchName,
            origin::store::SyncError::AlreadyInProgress => SyncWithConfigError::AlreadyInProgress,
            origin::store::SyncError::Unexpected(e) => SyncWithConfigError::Unexpected(e),
        }
    }
}

impl From<checker::CheckDomainError> for SyncWithConfigError {
    fn from(e: checker::CheckDomainError) -> SyncWithConfigError {
        match e {
            checker::CheckDomainError::TargetCNAMENotSet => SyncWithConfigError::TargetCNAMENotSet,
            checker::CheckDomainError::ChallengeTokenNotSet => {
                SyncWithConfigError::ChallengeTokenNotSet
            }
            checker::CheckDomainError::Unexpected(e) => SyncWithConfigError::Unexpected(e),
        }
    }
}

impl From<config::SetError> for SyncWithConfigError {
    fn from(e: config::SetError) -> SyncWithConfigError {
        match e {
            config::SetError::Unexpected(e) => SyncWithConfigError::Unexpected(e),
        }
    }
}

#[mockall::automock(type Origin=origin::MockOrigin;)]
pub trait Manager: std::marker::Send + std::marker::Sync {
    type Origin<'mgr>: origin::Origin + 'mgr
    where
        Self: 'mgr;

    fn get_config(&self, domain: &domain::Name) -> Result<config::Config, GetConfigError>;
    fn get_origin(&self, domain: &domain::Name) -> Result<Self::Origin<'_>, GetOriginError>;
    fn sync(&self, domain: &domain::Name) -> Result<(), SyncError>;
    fn sync_with_config(
        &self,
        domain: &domain::Name,
        config: &config::Config,
    ) -> Result<(), SyncWithConfigError>;
}

pub fn new<OriginStore, DomainConfigStore, DomainChecker>(
    origin_store: OriginStore,
    domain_config_store: DomainConfigStore,
    domain_checker: DomainChecker,
) -> impl Manager
where
    OriginStore: origin::store::Store,
    DomainConfigStore: config::Store,
    DomainChecker: checker::Checker,
{
    ManagerImpl {
        origin_store,
        domain_config_store,
        domain_checker,
    }
}

struct ManagerImpl<OriginStore, DomainConfigStore, DomainChecker>
where
    OriginStore: origin::store::Store,
    DomainConfigStore: config::Store,
    DomainChecker: checker::Checker,
{
    origin_store: OriginStore,
    domain_config_store: DomainConfigStore,
    domain_checker: DomainChecker,
}

impl<OriginStore, DomainConfigStore, DomainChecker> Manager
    for ManagerImpl<OriginStore, DomainConfigStore, DomainChecker>
where
    OriginStore: origin::store::Store,
    DomainConfigStore: config::Store,
    DomainChecker: checker::Checker,
{
    type Origin<'mgr> = OriginStore::Origin<'mgr>
            where Self: 'mgr;

    fn get_config(&self, domain: &domain::Name) -> Result<config::Config, GetConfigError> {
        Ok(self.domain_config_store.get(domain)?)
    }

    fn get_origin(&self, domain: &domain::Name) -> Result<Self::Origin<'_>, GetOriginError> {
        let config = self.domain_config_store.get(domain)?;
        let origin = self
            .origin_store
            .get(config.origin_descr)
            // if there's a config there should be an origin, any error here is unexpected
            .map_err(|e| GetOriginError::Unexpected(Box::from(e)))?;
        Ok(origin)
    }

    fn sync(&self, domain: &domain::Name) -> Result<(), SyncError> {
        let config = self.domain_config_store.get(domain)?;
        self.origin_store
            .sync(config.origin_descr, origin::store::Limits {})
            .map_err(|e| match e {
                origin::store::SyncError::AlreadyInProgress => SyncError::AlreadyInProgress,
                _ => SyncError::Unexpected(Box::from(e)),
            })?;
        Ok(())
    }

    fn sync_with_config(
        &self,
        domain: &domain::Name,
        config: &config::Config,
    ) -> Result<(), SyncWithConfigError> {
        let config_hash = config
            .hash()
            .map_err(|e| SyncWithConfigError::Unexpected(Box::from(e)))?;

        self.domain_checker.check_domain(domain, &config_hash)?;

        self.origin_store
            .sync(config.origin_descr.clone(), origin::store::Limits {})?;

        self.domain_config_store.set(domain, config)?;

        Ok(())
    }
}