use axum::http::StatusCode;
use axum::response::{IntoResponse, Response};
use export::data::{AppResponseData, NoData};
use thiserror::Error;

pub type ProjectResult<T> = Result<T, ProjectError>;

#[derive(Debug, Error)]
pub enum ProjectError {
    #[error("bad request: {0}")]
    BadRequest(String),
    #[error("unauthorized: {0}")]
    Unauthorized(String),
    #[error("forbidden: {0}")]
    Forbidden(String),
    #[error("not found: {0}")]
    NotFound(String),
    #[error("conflict: {0}")]
    Conflict(String),
    #[error("unprocessable: {0}")]
    Unprocessable(String),
    #[error("rate limited: {0}")]
    RateLimited(String),
    #[error("internal: {0}")]
    Internal(String),

    #[error("database error: {0}")]
    Database(#[from] db::conn::SqlxError),
    #[error("uuid: {0}")]
    Uuid(#[from] uuid::Error),
    #[error("serde_json: {0}")]
    Json(#[from] serde_json::Error),
    #[error("cache: {0}")]
    Cache(String),
    #[error("space: {0}")]
    Space(String),
}

impl From<axum::extract::rejection::JsonRejection> for ProjectError {
    fn from(re: axum::extract::rejection::JsonRejection) -> Self {
        ProjectError::BadRequest(re.body_text())
    }
}

impl From<axum::extract::rejection::PathRejection> for ProjectError {
    fn from(re: axum::extract::rejection::PathRejection) -> Self {
        ProjectError::BadRequest(re.body_text())
    }
}

impl From<axum::extract::rejection::QueryRejection> for ProjectError {
    fn from(re: axum::extract::rejection::QueryRejection) -> Self {
        ProjectError::BadRequest(re.body_text())
    }
}

impl ProjectError {
    fn status(&self) -> StatusCode {
        match self {
            ProjectError::BadRequest(_) => StatusCode::BAD_REQUEST,
            ProjectError::Unauthorized(_) => StatusCode::UNAUTHORIZED,
            ProjectError::Forbidden(_) => StatusCode::FORBIDDEN,
            ProjectError::NotFound(_) => StatusCode::NOT_FOUND,
            ProjectError::Conflict(_) => StatusCode::CONFLICT,
            ProjectError::Unprocessable(_) => StatusCode::UNPROCESSABLE_ENTITY,
            ProjectError::RateLimited(_) => StatusCode::TOO_MANY_REQUESTS,
            ProjectError::Internal(_)
            | ProjectError::Database(_)
            | ProjectError::Uuid(_)
            | ProjectError::Json(_)
            | ProjectError::Cache(_)
            | ProjectError::Space(_) => StatusCode::INTERNAL_SERVER_ERROR,
        }
    }

    fn is_user_facing(&self) -> bool {
        matches!(
            self,
            ProjectError::BadRequest(_)
                | ProjectError::Unauthorized(_)
                | ProjectError::Forbidden(_)
                | ProjectError::NotFound(_)
                | ProjectError::Conflict(_)
                | ProjectError::Unprocessable(_)
                | ProjectError::RateLimited(_)
        )
    }

    /// Bounded label for metrics. Keep stable and low-cardinality.
    pub fn error_kind(&self) -> &'static str {
        match self {
            ProjectError::BadRequest(_) => "bad_request",
            ProjectError::Unauthorized(_) => "unauthorized",
            ProjectError::Forbidden(_) => "forbidden",
            ProjectError::NotFound(_) => "not_found",
            ProjectError::Conflict(_) => "conflict",
            ProjectError::Unprocessable(_) => "unprocessable",
            ProjectError::RateLimited(_) => "rate_limited",
            ProjectError::Internal(_) => "internal_other",
            ProjectError::Database(_) => "internal_db",
            ProjectError::Uuid(_) => "internal_uuid",
            ProjectError::Json(_) => "internal_json",
            ProjectError::Cache(_) => "internal_cache",
            ProjectError::Space(_) => "internal_space",
        }
    }
}

impl IntoResponse for ProjectError {
    fn into_response(self) -> Response {
        let status = self.status();
        let msg = if self.is_user_facing() {
            self.to_string()
        } else {
            tracing::error!(error = %self, "project internal error");
            "internal error".to_string()
        };
        AppResponseData::<NoData>::err_plain(status.as_u16() as i32, msg).into_response()
    }
}