use crate::{
    client::Client,
    request::{self, AuditLogReason, AuditLogReasonError, NullableField, Request},
    response::ResponseFuture,
    routing::Route,
};
use serde::Serialize;
use twilight_model::{
    channel::Webhook,
    id::{ChannelId, WebhookId},
};

#[derive(Serialize)]
struct UpdateWebhookFields<'a> {
    #[serde(skip_serializing_if = "Option::is_none")]
    avatar: Option<NullableField<&'a str>>,
    #[serde(skip_serializing_if = "Option::is_none")]
    channel_id: Option<ChannelId>,
    #[serde(skip_serializing_if = "Option::is_none")]
    name: Option<NullableField<&'a str>>,
}

/// Update a webhook by ID.
#[must_use = "requests must be configured and executed"]
pub struct UpdateWebhook<'a> {
    fields: UpdateWebhookFields<'a>,
    http: &'a Client,
    webhook_id: WebhookId,
    reason: Option<&'a str>,
}

/// Update a webhook by its ID.
impl<'a> UpdateWebhook<'a> {
    pub(crate) const fn new(http: &'a Client, webhook_id: WebhookId) -> Self {
        Self {
            fields: UpdateWebhookFields {
                avatar: None,
                channel_id: None,
                name: None,
            },
            http,
            webhook_id,
            reason: None,
        }
    }

    /// Set the avatar of the webhook.
    ///
    /// See [Discord Docs/Image Data] for more information. This must be a Data URI, in the form of
    /// `data:image/{type};base64,{data}` where `{type}` is the image MIME type and `{data}` is the
    /// base64-encoded image.
    ///
    /// [Discord Docs/Image Data]: https://discord.com/developers/docs/reference#image-data
    pub const fn avatar(mut self, avatar: Option<&'a str>) -> Self {
        self.fields.avatar = Some(NullableField(avatar));

        self
    }

    /// Move this webhook to a new channel.
    pub const fn channel_id(mut self, channel_id: ChannelId) -> Self {
        self.fields.channel_id = Some(channel_id);

        self
    }

    /// Change the name of the webhook.
    pub const fn name(mut self, name: Option<&'a str>) -> Self {
        self.fields.name = Some(NullableField(name));

        self
    }

    /// Execute the request, returning a future resolving to a [`Response`].
    ///
    /// [`Response`]: crate::response::Response
    pub fn exec(self) -> ResponseFuture<Webhook> {
        let mut request = Request::builder(&Route::UpdateWebhook {
            token: None,
            webhook_id: self.webhook_id.get(),
        });

        request = match request.json(&self.fields) {
            Ok(request) => request,
            Err(source) => return ResponseFuture::error(source),
        };

        if let Some(reason) = self.reason.as_ref() {
            let header = match request::audit_header(reason) {
                Ok(header) => header,
                Err(source) => return ResponseFuture::error(source),
            };

            request = request.headers(header);
        }

        self.http.request(request.build())
    }
}

impl<'a> AuditLogReason<'a> for UpdateWebhook<'a> {
    fn reason(mut self, reason: &'a str) -> Result<Self, AuditLogReasonError> {
        self.reason.replace(AuditLogReasonError::validate(reason)?);

        Ok(self)
    }
}
