use crate::traits::{SEList, SEResource, SESubscriptionBase, Validate};
use anyhow::{bail, Context, Result};
use sep2_common_derive::{SEList, SEResource, SESubscriptionBase};
use xml::EventReader;
use yaserde::{YaDeserialize, YaSerialize};

use super::primitives::{Int48, String16, Uint32, Uint8};

/// Indicates a condition that must be satisfied for the Notification to be
/// triggered.
#[derive(Default, PartialEq, Eq, Debug, Clone, YaSerialize, YaDeserialize)]
#[yaserde(rename = "Condition")]
#[yaserde(namespace = "urn:ieee:std:2030.5:ns")]
pub struct Condition {
    /// 0 = Reading value
    /// 1-255 = Reserved
    #[yaserde(rename = "attributeIdentifier")]
    pub attribute_identifier: AttributeIdentifier,

    /// The value of the lower threshold
    #[yaserde(rename = "lowerThreshold")]
    pub lower_threshold: Int48,

    /// The value of the upper threshold
    #[yaserde(rename = "upperThreshold")]
    pub upper_threshold: Int48,
}

#[derive(Default, PartialEq, Eq, Debug, Clone, Copy, YaSerialize, YaDeserialize)]
#[yaserde(namespace = "urn:ieee:std:2030.5:ns")]
#[repr(u8)]
pub enum AttributeIdentifier {
    #[default]
    ReadingValue = 0,
    // 1-255 = Reserved
}

impl Validate for Condition {}

#[derive(Default, PartialEq, Eq, Debug, Clone, YaSerialize, YaDeserialize, SEResource)]
#[yaserde(rename = "SubscriptionBase")]
#[yaserde(namespace = "urn:ieee:std:2030.5:ns")]
pub struct SubscriptionBase {
    /// The resource for which the subscription applies. Query string parameters
    /// SHALL NOT be specified when subscribing to list resources. Should a query
    /// string parameter be specified, servers SHALL ignore them.
    #[yaserde(rename = "subscribedResource")]
    pub subscribed_resource: String,

    /// A reference to the resource address (URI). Required in a response to a
    /// GET, ignored otherwise.
    #[yaserde(attribute, rename = "href")]
    pub href: Option<String>,
}

impl Validate for SubscriptionBase {}

#[derive(
    Default, PartialEq, Eq, Debug, Clone, YaSerialize, YaDeserialize, SESubscriptionBase, SEResource,
)]
#[yaserde(rename = "Subscription")]
#[yaserde(namespace = "urn:ieee:std:2030.5:ns")]
pub struct Subscription {
    #[yaserde(rename = "Condition")]
    pub condition: Option<Condition>,

    /// 0 - application/sep+xml
    /// 1 - application/sep-exi
    /// 2-255 - reserved
    #[yaserde(rename = "encoding")]
    pub encoding: HTTPEncoding,

    /// Contains the preferred schema and extensibility level indication such as
    /// "+S1"
    #[yaserde(rename = "level")]
    pub level: String16,

    /// This element is used to indicate the maximum number of list items that
    /// should be included in a notification when the subscribed resource
    /// changes. This limit is meant to be functionally equivalent to the
    /// ‘limit’ query string parameter, but applies to both list resources as
    /// well as other resources. For list resources, if a limit of ‘0’ is
    /// specified, then notifications SHALL contain a list resource with
    /// results=’0’ (equivalent to a simple change notification). For list
    /// resources, if a limit greater than ‘0’ is specified, then
    /// notifications SHALL contain a list resource with results equal to the
    /// limit specified (or less, should the list contain fewer items than the
    /// limit specified or should the server be unable to provide the requested
    /// number of items for any reason) and follow the same rules for list
    /// resources (e.g., ordering). For non-list resources, if a limit of ‘0’
    /// is specified, then notifications SHALL NOT contain a resource
    /// representation (equivalent to a simple change notification). For non-list
    /// resources, if a limit greater than ‘0’ is specified, then
    /// notifications SHALL contain the representation of the changed resource.
    #[yaserde(rename = "limit")]
    pub limit: Uint32,

    /// The resource to which to post the notifications about the requested
    /// subscribed resource. Because this URI will exist on a server other than
    /// the one being POSTed to, this attribute SHALL be a fully-qualified
    /// absolute URI, not a relative reference.
    #[yaserde(rename = "notificationURI")]
    pub notification_uri: String,

    /// The resource for which the subscription applies. Query string parameters
    /// SHALL NOT be specified when subscribing to list resources. Should a query
    /// string parameter be specified, servers SHALL ignore them.
    #[yaserde(rename = "subscribedResource")]
    pub subscribed_resource: String,

    /// A reference to the resource address (URI). Required in a response to a
    /// GET, ignored otherwise.
    #[yaserde(attribute, rename = "href")]
    pub href: Option<String>,
}

#[derive(
    Default, PartialEq, PartialOrd, Eq, Ord, Debug, Clone, Copy, YaSerialize, YaDeserialize,
)]
#[yaserde(namespace = "urn:ieee:std:2030.5:ns")]
#[repr(u8)]
pub enum HTTPEncoding {
    #[default]
    SEPXML = 0,
    SEPEXI = 1,
}

impl PartialOrd for Subscription {
    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
        Some(self.cmp(other))
    }
}

impl Ord for Subscription {
    // Primary Key - href (ascending)
    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
        self.href.cmp(&other.href)
    }
}

impl Validate for Subscription {}

#[derive(Default, PartialEq, Eq, Debug, Clone, YaSerialize, YaDeserialize, SEList, SEResource)]
#[yaserde(rename = "SubscriptionList")]
#[yaserde(namespace = "urn:ieee:std:2030.5:ns")]
pub struct SubscriptionList {
    #[yaserde(rename = "Subscription")]
    pub subscription: Vec<Subscription>,

    /// The default polling rate for this function set (this resource and all
    /// resources below), in seconds. If not specified, a default of 900 seconds
    /// (15 minutes) is used. It is RECOMMENDED a client poll the resources of
    /// this function set every pollRate seconds.
    #[yaserde(attribute, rename = "pollRate")]
    pub poll_rate: Option<Uint32>,

    /// The number specifying "all" of the items in the list. Required on a
    /// response to a GET, ignored otherwise.
    #[yaserde(attribute, rename = "all")]
    pub all: Uint32,

    /// Indicates the number of items in this page of results.
    #[yaserde(attribute, rename = "results")]
    pub results: Uint32,

    /// A reference to the resource address (URI). Required in a response to a
    /// GET, ignored otherwise.
    #[yaserde(attribute, rename = "href")]
    pub href: Option<String>,
}

impl Validate for SubscriptionList {}

#[derive(
    Default, PartialEq, Eq, Debug, Clone, YaSerialize, YaDeserialize, SESubscriptionBase, SEResource,
)]
#[yaserde(rename = "Notification")]
#[yaserde(
    namespace = "urn:ieee:std:2030.5:ns",
    namespace = "xsi: http://www.w3.org/2001/XMLSchema-instance"
)]
pub struct Notification<T: SEResource> {
    /// The new location of the resource, if moved. This attribute SHALL be a
    /// fully-qualified absolute URI, not a relative reference.
    #[yaserde(rename = "newResourceURI")]
    pub new_resource_uri: Option<String>,

    #[yaserde(rename = "Resource")]
    #[yaserde(generic)]
    pub resource: Option<T>,

    /// 0 = Default Status
    /// 1 = Subscription canceled, no additional information
    /// 2 = Subscription canceled, resource moved
    /// 3 = Subscription canceled, resource definition changed (e.g., a new
    /// version of IEEE 2030.5)
    /// 4 = Subscription canceled, resource deleted
    /// All other values reserved.
    #[yaserde(rename = "status")]
    pub status: Uint8,

    /// The subscription from which this notification was triggered. This
    /// attribute SHALL be a fully-qualified absolute URI, not a relative
    /// reference.
    #[yaserde(rename = "subscriptionURI")]
    pub subscription_uri: String,

    /// The resource for which the subscription applies. Query string parameters
    /// SHALL NOT be specified when subscribing to list resources. Should a query
    /// string parameter be specified, servers SHALL ignore them.
    #[yaserde(rename = "subscribedResource")]
    pub subscribed_resource: String,

    /// A reference to the resource address (URI). Required in a response to a
    /// GET, ignored otherwise.
    #[yaserde(attribute, rename = "href")]
    pub href: Option<String>,
}

impl<T: SEResource + Eq> PartialOrd for Notification<T> {
    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
        Some(self.cmp(other))
    }
}

impl<T: SEResource + Eq> Ord for Notification<T> {
    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
        // Primary Key - href (ascending)
        self.href.cmp(&other.href)
    }
}

pub fn get_notif_type(notif_xml: &str) -> Result<String> {
    let parser = EventReader::new(notif_xml.as_bytes());
    for event in parser {
        match event? {
            xml::reader::XmlEvent::StartElement {
                name, attributes, ..
            } if name.local_name == "Resource" => {
                return Ok(attributes
                    .iter()
                    .find(|a| a.name.local_name == "type")
                    .context("Notification did not include a type annotation")?
                    .value
                    .clone())
            }
            _ => (),
        }
    }
    bail!("Notification did not contain an inner resource")
}

impl<T: SEResource> Validate for Notification<T> {}

#[derive(Default, PartialEq, Eq, Debug, Clone, YaSerialize, YaDeserialize, SEList, SEResource)]
#[yaserde(rename = "NotificationList")]
#[yaserde(
    namespace = "urn:ieee:std:2030.5:ns",
    namespace = "xsi: http://www.w3.org/2001/XMLSchema-instance"
)]
pub struct NotificationList<T: SEResource + Eq> {
    #[yaserde(rename = "Notification")]
    pub notification: Vec<Notification<T>>,

    /// The number specifying "all" of the items in the list. Required on a
    /// response to a GET, ignored otherwise.
    #[yaserde(attribute, rename = "all")]
    pub all: Uint32,

    /// Indicates the number of items in this page of results.
    #[yaserde(attribute, rename = "results")]
    pub results: Uint32,

    /// A reference to the resource address (URI). Required in a response to a
    /// GET, ignored otherwise.
    #[yaserde(attribute, rename = "href")]
    pub href: Option<String>,
}

impl<T: SEResource + Eq> Validate for NotificationList<T> {}