use axum::{
    http::StatusCode,
    response::{IntoResponse, Response},
    Json,
};
use serde::Serialize;
use serde_json::Value;
use std::fmt::{self, Display};
use utoipa::ToSchema;

pub type AppResult<T> = Result<T, AppError>;

#[derive(Debug)]
pub struct AppError {
    status: StatusCode,
    message: String,
    code: Option<String>,
    details: Option<Value>,
}

impl AppError {
    pub fn new(status: StatusCode, message: impl Into<String>) -> Self {
        Self {
            status,
            message: message.into(),
            code: None,
            details: None,
        }
    }

    pub fn bad_request(message: impl Into<String>) -> Self {
        Self::new(StatusCode::BAD_REQUEST, message)
    }

    pub fn conflict(message: impl Into<String>) -> Self {
        Self::new(StatusCode::CONFLICT, message)
    }

    pub fn unauthorized() -> Self {
        Self::new(StatusCode::UNAUTHORIZED, "unauthorized")
    }

    pub fn forbidden(message: impl Into<String>) -> Self {
        Self::new(StatusCode::FORBIDDEN, message)
    }

    pub fn not_found() -> Self {
        Self::new(StatusCode::NOT_FOUND, "resource not found")
    }

    pub fn internal<E: Display>(error: E) -> Self {
        Self::new(StatusCode::INTERNAL_SERVER_ERROR, error.to_string())
    }

    pub fn with_code(mut self, code: impl Into<String>) -> Self {
        self.code = Some(code.into());
        self
    }

    pub fn with_details(mut self, details: Value) -> Self {
        self.details = Some(details);
        self
    }
}

impl fmt::Display for AppError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}: {}", self.status, self.message)
    }
}

impl IntoResponse for AppError {
    fn into_response(self) -> Response {
        let status = self.status;
        let body = Json(ApiErrorResponse {
            error: self.message,
            code: self.code,
            details: self.details,
        });
        (status, body).into_response()
    }
}

#[derive(Serialize, ToSchema)]
pub struct ApiErrorResponse {
    error: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    code: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    details: Option<Value>,
}

impl From<diesel::result::Error> for AppError {
    fn from(value: diesel::result::Error) -> Self {
        match value {
            diesel::result::Error::NotFound => AppError::not_found(),
            other => {
                let message = format!("database operation failed: {other}");
                tracing::error!(error = ?other, message);
                AppError::internal(message)
            }
        }
    }
}

impl From<jsonwebtoken::errors::Error> for AppError {
    fn from(value: jsonwebtoken::errors::Error) -> Self {
        AppError::internal(value)
    }
}

impl From<anyhow::Error> for AppError {
    fn from(value: anyhow::Error) -> Self {
        AppError::internal(value)
    }
}

impl From<std::io::Error> for AppError {
    fn from(value: std::io::Error) -> Self {
        AppError::internal(value)
    }
}

impl From<serde_json::Error> for AppError {
    fn from(value: serde_json::Error) -> Self {
        AppError::internal(value)
    }
}