use std::fmt;
use std::error;

use actix_http::ResponseBuilder;
use actix_web as aweb;
use actix_web::http::StatusCode;
use serde_json::json;
use actix_web::error::JsonPayloadError;

use meilisearch_error::{ErrorCode, Code};

#[derive(Debug)]
pub struct ResponseError {
    inner: Box<dyn ErrorCode>,
}

impl fmt::Display for ResponseError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.inner.fmt(f)
    }
}

impl From<Error> for ResponseError {
    fn from(error: Error) -> ResponseError {
        ResponseError { inner: Box::new(error) }
    }
}

#[derive(Debug)]
pub enum Error {
    BadParameter(String, String),
    BadRequest(String),
    CreateIndex(String),
    DocumentNotFound(String),
    IndexNotFound(String),
    Internal(String),
    InvalidIndexUid,
    InvalidToken(String),
    Maintenance,
    MissingAuthorizationHeader,
    MissingHeader(String),
    NotFound(String),
    OpenIndex(String),
    RetrieveDocument(u32, String),
    SearchDocuments(String),
    PayloadTooLarge,
    UnsupportedMediaType,
}

impl error::Error for Error {}

impl ErrorCode for Error {
    fn error_code(&self) -> Code {
        use Error::*;
        match self {
            BadParameter(_, _) => Code::BadParameter,
            BadRequest(_) => Code::BadRequest,
            CreateIndex(_) => Code::CreateIndex,
            DocumentNotFound(_) => Code::DocumentNotFound,
            IndexNotFound(_) => Code::IndexNotFound,
            Internal(_) => Code::Internal,
            InvalidIndexUid => Code::InvalidIndexUid,
            InvalidToken(_) => Code::InvalidToken,
            Maintenance => Code::Maintenance,
            MissingAuthorizationHeader => Code::MissingAuthorizationHeader,
            MissingHeader(_) => Code::MissingHeader,
            NotFound(_) => Code::NotFound,
            OpenIndex(_) => Code::OpenIndex,
            RetrieveDocument(_, _) => Code::RetrieveDocument,
            SearchDocuments(_) => Code::SearchDocuments,
            PayloadTooLarge => Code::PayloadTooLarge,
            UnsupportedMediaType => Code::UnsupportedMediaType,
        }
    }
}

#[derive(Debug)]
pub enum FacetCountError {
    AttributeNotSet(String),
    SyntaxError(String),
    UnexpectedToken { found: String, expected: &'static [&'static str] },
    NoFacetSet,
}

impl error::Error for FacetCountError {}

impl ErrorCode for FacetCountError {
    fn error_code(&self) -> Code {
        Code::BadRequest
    }
}

impl FacetCountError {
    pub fn unexpected_token(found: impl ToString, expected: &'static [&'static str]) -> FacetCountError {
        let found = found.to_string();
        FacetCountError::UnexpectedToken { expected, found }
    }
}

impl From<serde_json::error::Error> for FacetCountError {
    fn from(other: serde_json::error::Error) -> FacetCountError {
        FacetCountError::SyntaxError(other.to_string())
    }
}

impl fmt::Display for FacetCountError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        use FacetCountError::*;

        match self {
            AttributeNotSet(attr) => write!(f, "attribute {} is not set as facet", attr),
            SyntaxError(msg) => write!(f, "syntax error: {}", msg),
            UnexpectedToken { expected, found } => write!(f, "unexpected {} found, expected {:?}", found, expected),
            NoFacetSet => write!(f, "can't perform facet count, as no facet is set"),
        }
    }
}

impl Error {
    pub fn internal(err: impl fmt::Display) -> Error {
        Error::Internal(err.to_string())
    }

    pub fn bad_request(err: impl fmt::Display) -> Error {
        Error::BadRequest(err.to_string())
    }

    pub fn missing_authorization_header() -> Error {
        Error::MissingAuthorizationHeader
    }

    pub fn invalid_token(err: impl fmt::Display) -> Error {
        Error::InvalidToken(err.to_string())
    }

    pub fn not_found(err: impl fmt::Display) -> Error {
        Error::NotFound(err.to_string())
    }

    pub fn index_not_found(err: impl fmt::Display) -> Error {
        Error::IndexNotFound(err.to_string())
    }

    pub fn document_not_found(err: impl fmt::Display) -> Error {
        Error::DocumentNotFound(err.to_string())
    }

    pub fn missing_header(err: impl fmt::Display) -> Error {
        Error::MissingHeader(err.to_string())
    }

    pub fn bad_parameter(param: impl fmt::Display, err: impl fmt::Display) -> Error {
        Error::BadParameter(param.to_string(), err.to_string())
    }

    pub fn open_index(err: impl fmt::Display) -> Error {
        Error::OpenIndex(err.to_string())
    }

    pub fn create_index(err: impl fmt::Display) -> Error {
        Error::CreateIndex(err.to_string())
    }

    pub fn invalid_index_uid() -> Error {
        Error::InvalidIndexUid
    }

    pub fn maintenance() -> Error {
        Error::Maintenance
    }

    pub fn retrieve_document(doc_id: u32, err: impl fmt::Display) -> Error {
        Error::RetrieveDocument(doc_id, err.to_string())
    }

    pub fn search_documents(err: impl fmt::Display) -> Error {
        Error::SearchDocuments(err.to_string())
    }
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::BadParameter(param, err) => write!(f, "Url parameter {} error: {}", param, err),
            Self::BadRequest(err) => f.write_str(err),
            Self::CreateIndex(err) => write!(f, "Impossible to create index; {}", err),
            Self::DocumentNotFound(document_id) => write!(f, "Document with id {} not found", document_id),
            Self::IndexNotFound(index_uid) => write!(f, "Index {} not found", index_uid),
            Self::Internal(err) => f.write_str(err),
            Self::InvalidIndexUid => f.write_str("Index must have a valid uid; Index uid can be of type integer or string only composed of alphanumeric characters, hyphens (-) and underscores (_)."),
            Self::InvalidToken(err) => write!(f, "Invalid API key: {}", err),
            Self::Maintenance => f.write_str("Server is in maintenance, please try again later"),
            Self::MissingAuthorizationHeader => f.write_str("You must have an authorization token"),
            Self::MissingHeader(header) => write!(f, "Header {} is missing", header),
            Self::NotFound(err) => write!(f, "{} not found", err),
            Self::OpenIndex(err) => write!(f, "Impossible to open index; {}", err),
            Self::RetrieveDocument(id, err) => write!(f, "impossible to retrieve the document with id: {}; {}", id, err),
            Self::SearchDocuments(err) => write!(f, "impossible to search documents; {}", err),
            Self::PayloadTooLarge => f.write_str("Payload to large"),
            Self::UnsupportedMediaType => f.write_str("Unsupported media type"),
        }
    }
}

impl aweb::error::ResponseError for ResponseError {
    fn error_response(&self) -> aweb::HttpResponse {
        let error_code = self.inner.error_code().internal();
        ResponseBuilder::new(self.status_code()).json(json!({
            "message": self.to_string(),
            "errorCode": error_code,
            "errorLink": format!("docs.meilisearch.come/error/{}", error_code),
        }))
    }

    fn status_code(&self) -> StatusCode {
        self.inner.error_code().http()
    }
}

impl From<meilisearch_core::Error> for ResponseError {
    fn from(err: meilisearch_core::Error) -> ResponseError {
        ResponseError { inner: Box::new(err) }
    }
}

impl From<meilisearch_schema::Error> for ResponseError {
    fn from(err: meilisearch_schema::Error) -> ResponseError {
        ResponseError { inner: Box::new(err) }
    }
}

impl From<actix_http::Error> for Error {
    fn from(err: actix_http::Error) -> Error {
        Error::Internal(err.to_string())
    }
}

impl From<FacetCountError> for ResponseError {
    fn from(err: FacetCountError) -> ResponseError {
        ResponseError { inner: Box::new(err) }
    }
}

impl From<JsonPayloadError> for Error {
    fn from(err: JsonPayloadError) -> Error {
        match err {
            JsonPayloadError::Deserialize(err) => Error::BadRequest(format!("Invalid JSON: {}", err)),
            JsonPayloadError::Overflow => Error::PayloadTooLarge,
            JsonPayloadError::ContentType => Error::UnsupportedMediaType,
            JsonPayloadError::Payload(err) => Error::BadRequest(format!("Problem while decoding the request: {}", err)),
        }
    }
}

pub fn json_error_handler(err: JsonPayloadError) -> ResponseError {
    let error = Error::from(err);
    error.into()
}