//! Core functionality and types for BonsaiDb.

#![forbid(unsafe_code)]
#![warn(
    clippy::cargo,
    missing_docs,
    // clippy::missing_docs_in_private_items,
    clippy::pedantic,
    future_incompatible,
    rust_2018_idioms,
)]
#![allow(
    clippy::missing_errors_doc, // TODO clippy::missing_errors_doc
    clippy::option_if_let_else,
    clippy::module_name_repetitions,
    clippy::use_self, // false positives that can't be allowed on the type declaration itself.
)]

/// Types for creating and validating permissions.
pub mod permissions;

/// Database administration types and functionality.
pub mod admin;
/// Types for interacting with BonsaiDb.
pub mod connection;
pub mod document;
pub mod limits;
/// Types for defining database schema.
pub mod schema;
/// Types for executing transactions.
pub mod transaction;

/// Types for utilizing a lightweight atomic Key-Value store.
pub mod keyvalue;

/// Traits for tailoring a server.
pub mod api;

/// Key trait and related types.
pub mod key;

/// Types for implementing the BonsaiDb network protocol.
pub mod networking;

/// Types for Publish/Subscribe (`PubSub`) messaging.
pub mod pubsub;

use std::fmt::Display;
use std::string::FromUtf8Error;

use schema::{view, CollectionName, SchemaName, ViewName};
use serde::{Deserialize, Serialize};
pub use {
    actionable, arc_bytes, async_trait, circulate, num_traits, ordered_varint, transmog,
    transmog_pot,
};

use crate::api::ApiName;
use crate::connection::HasSchema;
use crate::document::{DocumentId, Header, InvalidHexadecimal};
use crate::key::time::TimeError;
use crate::key::NextValueError;
use crate::schema::InsertError;

/// an enumeration of errors that this crate can produce
#[derive(Clone, thiserror::Error, Debug, Serialize, Deserialize)]
pub enum Error {
    /// The database named `database_name` was created with a different schema
    /// (`stored_schema`) than provided (`schema`).
    #[error(
        "database '{database_name}' was created with schema '{stored_schema}', not '{schema}'"
    )]
    SchemaMismatch {
        /// The name of the database being accessed.
        database_name: String,

        /// The schema provided for the database.
        schema: SchemaName,

        /// The schema stored for the database.
        stored_schema: SchemaName,
    },

    /// The [`SchemaName`] returned has already been registered.
    #[error("schema '{0}' was already registered")]
    SchemaAlreadyRegistered(SchemaName),

    /// The [`SchemaName`] requested was not registered.
    #[error("schema '{0}' is not registered")]
    SchemaNotRegistered(SchemaName),

    /// The [`ViewName`] returned has already been registered.
    #[error("view '{0}' was already registered")]
    ViewAlreadyRegistered(ViewName),

    /// An invalid database name was specified. See
    /// [`StorageConnection::create_database()`](connection::StorageConnection::create_database)
    /// for database name requirements.
    #[error("invalid database name: {0}")]
    InvalidDatabaseName(String),

    /// The database name given was not found.
    #[error("database '{0}' was not found")]
    DatabaseNotFound(String),

    /// The view was not found.
    #[error("view was not found")]
    ViewNotFound,

    /// The collection was not found.
    #[error("collection was not found")]
    CollectionNotFound,

    /// The api invoked was not found.
    #[error("api '{0}' was not found")]
    ApiNotFound(ApiName),

    /// The database name already exists.
    #[error("a database with name '{0}' already exists")]
    DatabaseNameAlreadyTaken(String),

    /// An error occurred from networking.
    #[error("a networking error occurred: '{0}'")]
    Networking(networking::Error),

    /// A `Collection` being added already exists. This can be caused by a collection name not being unique.
    #[error("attempted to define a collection that already has been defined")]
    CollectionAlreadyDefined,

    /// An attempt to update a document that doesn't exist.
    #[error("the requested document id {1} from collection {0} was not found")]
    DocumentNotFound(CollectionName, Box<DocumentId>),

    /// A value provided as a [`DocumentId`] exceeded [`DocumentId::MAX_LENGTH`].
    #[error(
        "an value was provided for a `DocumentId` that was larger than `DocumentId::MAX_LENGTH`"
    )]
    DocumentIdTooLong,

    /// When updating a document, if a situation is detected where the contents
    /// have changed on the server since the `Revision` provided, a Conflict
    /// error will be returned.
    #[error("a conflict was detected while updating document {1} from collection {0}")]
    DocumentConflict(CollectionName, Box<Header>),

    /// When saving a document in a collection with unique views, a document
    /// emits a key that is already emitted by an existing ocument, this error
    /// is returned.
    #[error("a unique key violation occurred: document `{existing_document}` already has the same key as `{conflicting_document}` for {view}")]
    UniqueKeyViolation {
        /// The name of the view that the unique key violation occurred.
        view: ViewName,
        /// The document that caused the violation.
        conflicting_document: Box<Header>,
        /// The document that already uses the same key.
        existing_document: Box<Header>,
    },

    /// When pushing a document, an error occurred while generating the next unique id.
    #[error("an error occurred generating a new unique id for {0}: {1}")]
    DocumentPush(CollectionName, NextValueError),

    /// An invalid name was specified during schema creation.
    #[error("an invalid name was used in a schema: {0}")]
    InvalidName(#[from] schema::InvalidNameError),

    /// Permission was denied.
    #[error("permission error: {0}")]
    PermissionDenied(#[from] actionable::PermissionDenied),

    /// An internal error handling passwords was encountered.
    #[error("error with password: {0}")]
    Password(String),

    /// The user specified was not found. This will not be returned in response
    /// to an invalid username being used during login. It will be returned in
    /// other APIs that operate upon users.
    #[error("user not found")]
    UserNotFound,

    /// An error occurred converting from bytes to Utf-8.
    #[error("invalid string: {0}")]
    InvalidUnicode(String),

    /// The credentials specified are not valid.
    #[error("invalid credentials")]
    InvalidCredentials,

    /// Returned when the a view's reduce() function is unimplemented.
    #[error("reduce is unimplemented")]
    ReduceUnimplemented,

    /// A floating point operation yielded Not a Number.
    #[error("floating point operation yielded NaN")]
    NotANumber,

    /// An error while operating with a time
    #[error("time error: {0}")]
    Time(#[from] TimeError),

    /// An error from another crate.
    #[error("error from {origin}: {error}")]
    Other {
        /// The origin of the error.
        origin: String,
        /// The error message.
        error: String,
    },
}

impl Error {
    /// Returns an instance of [`Self::Other`] with the given parameters.
    pub fn other(origin: impl Display, error: impl Display) -> Self {
        Self::Other {
            origin: origin.to_string(),
            error: error.to_string(),
        }
    }

    /// Returns true if this error is a [`Error::UniqueKeyViolation`] from
    /// `View`.
    pub fn is_unique_key_error<View: schema::View, C: HasSchema>(&self, connection: &C) -> bool {
        if let Self::UniqueKeyViolation { view, .. } = self {
            if let Ok(schema_view) = connection.schematic().view::<View>() {
                return view == &schema_view.view_name();
            }
        }

        false
    }

    /// Returns the header of the conflicting document if this error is a
    /// [`Error::DocumentConflict`] from `Collection`.
    #[must_use]
    pub fn conflicting_document<Collection: schema::Collection>(&self) -> Option<Header> {
        match self {
            Self::DocumentConflict(collection, header)
                if collection == &Collection::collection_name() =>
            {
                Some(header.as_ref().clone())
            }
            _ => None,
        }
    }
}

impl From<pot::Error> for Error {
    fn from(err: pot::Error) -> Self {
        Self::other("pot", err)
    }
}

impl<T> From<InsertError<T>> for Error {
    fn from(err: InsertError<T>) -> Self {
        err.error
    }
}

impl From<view::Error> for Error {
    fn from(err: view::Error) -> Self {
        Self::other("view", err)
    }
}

impl From<FromUtf8Error> for Error {
    fn from(err: FromUtf8Error) -> Self {
        Self::InvalidUnicode(err.to_string())
    }
}

impl From<InvalidHexadecimal> for Error {
    fn from(err: InvalidHexadecimal) -> Self {
        Self::other("invalid hexadecimal", err)
    }
}

/// Shared schemas and utilities used for unit testing.
#[cfg(any(feature = "test-util", test))]
#[allow(missing_docs)]
pub mod test_util;

/// When true, encryption was enabled at build-time.
#[cfg(feature = "encryption")]
pub const ENCRYPTION_ENABLED: bool = true;

/// When true, encryption was enabled at build-time.
#[cfg(not(feature = "encryption"))]
pub const ENCRYPTION_ENABLED: bool = false;

/// A type that implements [`Error`](std::error::Error) and is threadsafe.
pub trait AnyError: std::error::Error + Send + Sync + 'static {}

impl<T> AnyError for T where T: std::error::Error + Send + Sync + 'static {}