nostr_types/versioned/
event1.rs

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use super::{TagV1, ZapDataV1};
use crate::types::{
    EventDelegation, EventKind, EventReference, Id, MilliSatoshi, NAddr, NostrBech32, NostrUrl,
    PublicKey, PublicKeyHex, RelayUrl, Signature, Unixtime,
};
use crate::{Error, IntoVec};
use lightning_invoice::Bolt11Invoice;
#[cfg(feature = "speedy")]
use regex::Regex;
use serde::{Deserialize, Serialize};
#[cfg(feature = "speedy")]
use speedy::{Readable, Writable};
use std::str::FromStr;

/// The main event type
#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
#[cfg_attr(feature = "speedy", derive(Readable, Writable))]
pub struct EventV1 {
    /// The Id of the event, generated as a SHA256 of the inner event data
    pub id: Id,

    /// The public key of the actor who created the event
    pub pubkey: PublicKey,

    /// The (unverified) time at which the event was created
    pub created_at: Unixtime,

    /// The kind of event
    pub kind: EventKind,

    /// The signature of the event, which cryptographically verifies that the holder of
    /// the PrivateKey matching the event's PublicKey generated (or authorized) this event.
    /// The signature is taken over the id field only, but the id field is taken over
    /// the rest of the event data.
    pub sig: Signature,

    /// DEPRECATED (please set to Null): An optional verified time for the event (using OpenTimestamp)
    #[serde(skip_serializing_if = "Option::is_none")]
    #[serde(default)]
    pub ots: Option<String>,

    /// The content of the event
    pub content: String,

    /// A set of tags that apply to the event
    pub tags: Vec<TagV1>,
}

macro_rules! serialize_inner_event {
    ($pubkey:expr, $created_at:expr, $kind:expr, $tags:expr,
     $content:expr) => {{
        format!(
            "[0,{},{},{},{},{}]",
            serde_json::to_string($pubkey)?,
            serde_json::to_string($created_at)?,
            serde_json::to_string($kind)?,
            serde_json::to_string($tags)?,
            serde_json::to_string($content)?
        )
    }};
}

/// Data used to construct an event
#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
#[cfg_attr(feature = "speedy", derive(Readable, Writable))]
pub struct PreEventV1 {
    /// The public key of the actor who is creating the event
    pub pubkey: PublicKey,
    /// The time at which the event was created
    pub created_at: Unixtime,
    /// The kind of event
    pub kind: EventKind,
    /// A set of tags that apply to the event
    pub tags: Vec<TagV1>,
    /// The content of the event
    pub content: String,
}

impl PreEventV1 {
    /// Generate an ID from this PreEvent for use in an Event or a Rumor
    pub fn hash(&self) -> Result<Id, Error> {
        use secp256k1::hashes::Hash;

        let serialized: String = serialize_inner_event!(
            &self.pubkey,
            &self.created_at,
            &self.kind,
            &self.tags,
            &self.content
        );

        // Hash
        let hash = secp256k1::hashes::sha256::Hash::hash(serialized.as_bytes());
        let id: [u8; 32] = hash.to_byte_array();
        Ok(Id(id))
    }
}

/// A Rumor is an Event without a signature
#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
#[cfg_attr(feature = "speedy", derive(Readable, Writable))]
pub struct RumorV1 {
    /// The Id of the event, generated as a SHA256 of the inner event data
    pub id: Id,

    /// The public key of the actor who created the event
    pub pubkey: PublicKey,

    /// The (unverified) time at which the event was created
    pub created_at: Unixtime,

    /// The kind of event
    pub kind: EventKind,

    /// The content of the event
    pub content: String,

    /// A set of tags that apply to the event
    pub tags: Vec<TagV1>,
}

impl RumorV1 {
    /// Create a new rumor
    pub fn new(input: PreEventV1) -> Result<RumorV1, Error> {
        // Generate Id
        let id = input.hash()?;

        Ok(RumorV1 {
            id,
            pubkey: input.pubkey,
            created_at: input.created_at,
            kind: input.kind,
            tags: input.tags,
            content: input.content,
        })
    }

    /// Turn into an Event (the signature will be all zeroes)
    pub fn into_event_with_bad_signature(self) -> EventV1 {
        EventV1 {
            id: self.id,
            pubkey: self.pubkey,
            created_at: self.created_at,
            kind: self.kind,
            sig: Signature::zeroes(),
            ots: None,
            content: self.content,
            tags: self.tags,
        }
    }
}

impl EventV1 {
    /// Check the validity of an event. This is useful if you deserialize an event
    /// from the network. If you create an event using new() it should already be
    /// trustworthy.
    pub fn verify(&self, maxtime: Option<Unixtime>) -> Result<(), Error> {
        use secp256k1::hashes::Hash;

        let serialized: String = serialize_inner_event!(
            &self.pubkey,
            &self.created_at,
            &self.kind,
            &self.tags,
            &self.content
        );

        // Verify the signature
        self.pubkey.verify(serialized.as_bytes(), &self.sig)?;

        // Also verify the ID is the SHA256
        // (the above verify function also does it internally,
        //  so there is room for improvement here)
        let hash = secp256k1::hashes::sha256::Hash::hash(serialized.as_bytes());
        let id: [u8; 32] = hash.to_byte_array();

        // Optional verify that the message was in the past
        if let Some(mt) = maxtime {
            if self.created_at > mt {
                return Err(Error::EventInFuture);
            }
        }

        if id != self.id.0 {
            Err(Error::HashMismatch)
        } else {
            Ok(())
        }
    }

    /// Get the k-tag kind, if any
    pub fn k_tag_kind(&self) -> Option<EventKind> {
        for tag in self.tags.iter() {
            if let TagV1::Kind { kind, .. } = tag {
                return Some(*kind);
            }
        }
        None
    }

    /// If the event refers to people by tag, get all the PublicKeys it refers to
    /// along with recommended relay URL and petname for each
    pub fn people(&self) -> Vec<(PublicKeyHex, Option<RelayUrl>, Option<String>)> {
        let mut output: Vec<(PublicKeyHex, Option<RelayUrl>, Option<String>)> = Vec::new();
        // All 'p' tags
        for tag in self.tags.iter() {
            if let TagV1::Pubkey {
                pubkey,
                recommended_relay_url,
                petname,
                ..
            } = tag
            {
                output.push((
                    pubkey.to_owned(),
                    recommended_relay_url
                        .as_ref()
                        .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok()),
                    petname.to_owned(),
                ));
            }
        }

        output
    }

    /// If the pubkey is tagged in the event
    pub fn is_tagged(&self, pubkey: &PublicKey) -> bool {
        let pkh: PublicKeyHex = pubkey.into();

        for tag in self.tags.iter() {
            if let TagV1::Pubkey { pubkey, .. } = tag {
                if *pubkey == pkh {
                    return true;
                }
            }
        }

        false
    }

    /// If the event refers to people within the contents, get all the PublicKeys it refers
    /// to within the contents.
    pub fn people_referenced_in_content(&self) -> Vec<PublicKey> {
        let mut output = Vec::new();
        for nurl in NostrUrl::find_all_in_string(&self.content).drain(..) {
            if let NostrBech32::Pubkey(pk) = nurl.0 {
                output.push(pk);
            }
            if let NostrBech32::Profile(prof) = nurl.0 {
                output.push(prof.pubkey);
            }
        }
        output
    }

    /// All events IDs that this event refers to, whether root, reply, mention, or otherwise
    /// along with optional recommended relay URLs
    pub fn referred_events(&self) -> Vec<EventReference> {
        let mut output: Vec<EventReference> = Vec::new();

        // Collect every 'e' tag and 'a' tag
        for tag in self.tags.iter() {
            if let TagV1::Event {
                id,
                recommended_relay_url,
                marker,
                ..
            } = tag
            {
                output.push(EventReference::Id {
                    id: *id,
                    author: None,
                    relays: recommended_relay_url
                        .as_ref()
                        .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok())
                        .into_vec(),
                    marker: marker.clone(),
                });
            } else if let TagV1::Address {
                kind,
                pubkey,
                d,
                relay_url: Some(rurl),
                ..
            } = tag
            {
                if let Ok(pk) = PublicKey::try_from_hex_string(pubkey.as_str(), true) {
                    output.push(EventReference::Addr(NAddr {
                        d: d.to_string(),
                        relays: vec![rurl.clone()],
                        kind: *kind,
                        author: pk,
                    }));
                }
            }
        }

        output
    }

    /// Get a reference to another event that this event replies to.
    /// An event can only reply to one other event via 'e' or 'a' tag from a feed-displayable
    /// event that is not a Repost.
    pub fn replies_to(&self) -> Option<EventReference> {
        if !self.kind.is_feed_displayable() {
            return None;
        }

        // Repost 'e' and 'a' tags are always considered mentions, not replies.
        if self.kind == EventKind::Repost || self.kind == EventKind::GenericRepost {
            return None;
        }

        // If there are no 'e' tags nor 'a' tags, then none
        let num_event_ref_tags = self
            .tags
            .iter()
            .filter(|e| matches!(e, TagV1::Event { .. }) || matches!(e, TagV1::Address { .. }))
            .count();
        if num_event_ref_tags == 0 {
            return None;
        }

        // look for an 'e' tag with marker 'reply'
        for tag in self.tags.iter() {
            if let TagV1::Event {
                id,
                recommended_relay_url,
                marker,
                ..
            } = tag
            {
                if marker.is_some() && marker.as_deref().unwrap() == "reply" {
                    return Some(EventReference::Id {
                        id: *id,
                        author: None,
                        relays: recommended_relay_url
                            .as_ref()
                            .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok())
                            .into_vec(),
                        marker: marker.clone(),
                    });
                }
            }
        }

        // look for an 'e' tag with marker 'root'
        for tag in self.tags.iter() {
            if let TagV1::Event {
                id,
                recommended_relay_url,
                marker,
                ..
            } = tag
            {
                if marker.is_some() && marker.as_deref().unwrap() == "root" {
                    return Some(EventReference::Id {
                        id: *id,
                        author: None,
                        relays: recommended_relay_url
                            .as_ref()
                            .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok())
                            .into_vec(),
                        marker: marker.clone(),
                    });
                }
            }
        }

        // Use the last unmarked 'e' tag or any 'a' tag
        if let Some(tag) = self.tags.iter().rev().find(|t| {
            matches!(t, TagV1::Event { marker: None, .. }) || matches!(t, TagV1::Address { .. })
        }) {
            if let TagV1::Event {
                id,
                recommended_relay_url,
                marker,
                ..
            } = tag
            {
                return Some(EventReference::Id {
                    id: *id,
                    author: None,
                    relays: recommended_relay_url
                        .as_ref()
                        .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok())
                        .into_vec(),
                    marker: marker.to_owned(),
                });
            } else if let TagV1::Address {
                kind,
                pubkey,
                d,
                relay_url: Some(rurl),
                ..
            } = tag
            {
                if let Ok(pk) = PublicKey::try_from_hex_string(pubkey.as_str(), true) {
                    return Some(EventReference::Addr(NAddr {
                        d: d.to_string(),
                        relays: vec![rurl.clone()],
                        kind: *kind,
                        author: pk,
                    }));
                }
            }
        }

        None
    }

    /// If this event replies to a thread, get that threads root event Id if
    /// available, along with an optional recommended_relay_url
    pub fn replies_to_root(&self) -> Option<EventReference> {
        if !self.kind.is_feed_displayable() {
            return None;
        }

        // look for an 'e' tag with marker 'root'
        for tag in self.tags.iter() {
            if let TagV1::Event {
                id,
                recommended_relay_url,
                marker,
                ..
            } = tag
            {
                if marker.is_some() && marker.as_deref().unwrap() == "root" {
                    return Some(EventReference::Id {
                        id: *id,
                        author: None,
                        relays: recommended_relay_url
                            .as_ref()
                            .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok())
                            .into_vec(),
                        marker: marker.to_owned(),
                    });
                }
            }
        }

        // otherwise use the first unmarked 'e' tag or first 'a' tag
        // (even if there is only 1 'e' or 'a' tag which means it is both root and reply)
        if let Some(tag) = self.tags.iter().find(|t| {
            matches!(t, TagV1::Event { marker: None, .. }) || matches!(t, TagV1::Address { .. })
        }) {
            if let TagV1::Event {
                id,
                recommended_relay_url,
                marker,
                ..
            } = tag
            {
                return Some(EventReference::Id {
                    id: *id,
                    author: None,
                    relays: recommended_relay_url
                        .as_ref()
                        .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok())
                        .into_vec(),
                    marker: marker.to_owned(),
                });
            } else if let TagV1::Address {
                kind,
                pubkey,
                d,
                relay_url: Some(rurl),
                ..
            } = tag
            {
                if let Ok(pk) = PublicKey::try_from_hex_string(pubkey.as_str(), true) {
                    return Some(EventReference::Addr(NAddr {
                        d: d.to_string(),
                        relays: vec![rurl.clone()],
                        kind: *kind,
                        author: pk,
                    }));
                }
            }
        }

        None
    }

    /// If this event mentions others, get those other event Ids
    /// and optional recommended relay Urls
    pub fn mentions(&self) -> Vec<EventReference> {
        if !self.kind.is_feed_displayable() {
            return vec![];
        }

        let mut output: Vec<EventReference> = Vec::new();

        // For kind=6 and kind=16, all 'e' and 'a' tags are mentions
        if self.kind == EventKind::Repost || self.kind == EventKind::GenericRepost {
            for tag in self.tags.iter() {
                if let TagV1::Event {
                    id,
                    recommended_relay_url,
                    marker,
                    ..
                } = tag
                {
                    output.push(EventReference::Id {
                        id: *id,
                        author: None,
                        relays: recommended_relay_url
                            .as_ref()
                            .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok())
                            .into_vec(),
                        marker: marker.to_owned(),
                    });
                } else if let TagV1::Address {
                    kind,
                    pubkey,
                    d,
                    relay_url: Some(rurl),
                    trailing: _,
                } = tag
                {
                    if let Ok(pk) = PublicKey::try_from_hex_string(pubkey.as_str(), true) {
                        output.push(EventReference::Addr(NAddr {
                            d: d.to_string(),
                            relays: vec![rurl.clone()],
                            kind: *kind,
                            author: pk,
                        }));
                    }
                }
            }

            return output;
        }

        // Look for nostr links within the content

        // Collect every 'e' tag marked as 'mention'
        for tag in self.tags.iter() {
            if let TagV1::Event {
                id,
                recommended_relay_url,
                marker,
                ..
            } = tag
            {
                if marker.is_some() && marker.as_deref().unwrap() == "mention" {
                    output.push(EventReference::Id {
                        id: *id,
                        author: None,
                        relays: recommended_relay_url
                            .as_ref()
                            .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok())
                            .into_vec(),
                        marker: marker.clone(),
                    });
                }
            }
        }

        // Collect every unmarked 'e' or 'a' tag that is not the first (root) or the last (reply)
        let e_tags: Vec<&TagV1> = self
            .tags
            .iter()
            .filter(|e| {
                matches!(e, TagV1::Event { marker: None, .. }) || matches!(e, TagV1::Address { .. })
            })
            .collect();
        if e_tags.len() > 2 {
            // mentions are everything other than first and last
            for tag in &e_tags[1..e_tags.len() - 1] {
                if let TagV1::Event {
                    id,
                    recommended_relay_url,
                    marker,
                    ..
                } = tag
                {
                    output.push(EventReference::Id {
                        id: *id,
                        author: None,
                        relays: recommended_relay_url
                            .as_ref()
                            .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok())
                            .into_vec(),
                        marker: marker.to_owned(),
                    });
                } else if let TagV1::Address {
                    kind,
                    pubkey,
                    d,
                    relay_url: Some(rurl),
                    ..
                } = tag
                {
                    if let Ok(pk) = PublicKey::try_from_hex_string(pubkey.as_str(), true) {
                        output.push(EventReference::Addr(NAddr {
                            d: d.to_string(),
                            relays: vec![rurl.clone()],
                            kind: *kind,
                            author: pk,
                        }));
                    }
                }
            }
        }

        output
    }

    /// If this event reacts to another, get that other event's Id,
    /// the reaction content, and an optional Recommended relay Url
    pub fn reacts_to(&self) -> Option<(Id, String, Option<RelayUrl>)> {
        if self.kind != EventKind::Reaction {
            return None;
        }

        // The last 'e' tag is it
        if let Some(TagV1::Event {
            id,
            recommended_relay_url,
            ..
        }) = self
            .tags
            .iter()
            .rev()
            .find(|t| matches!(t, TagV1::Event { .. }))
        {
            return Some((
                *id,
                self.content.clone(),
                recommended_relay_url
                    .as_ref()
                    .and_then(|rru| RelayUrl::try_from_unchecked_url(rru).ok()),
            ));
        }

        None
    }

    /// If this event deletes others, get all the Ids of the events that it deletes
    /// along with the reason for the deletion
    pub fn deletes(&self) -> Option<(Vec<Id>, String)> {
        if self.kind != EventKind::EventDeletion {
            return None;
        }

        let mut ids: Vec<Id> = Vec::new();

        // All 'e' tags are deleted
        for tag in self.tags.iter() {
            if let TagV1::Event { id, .. } = tag {
                ids.push(*id);
            }
        }

        if ids.is_empty() {
            None
        } else {
            Some((ids, self.content.clone()))
        }
    }

    /// If this event zaps another event, get data about that.
    ///
    /// That includes the Id, the amount, and the public key of the provider,
    /// all of which should be verified by the caller.
    ///
    /// Errors returned from this are not fatal, but may be useful for
    /// explaining to a user why a zap receipt is invalid.
    pub fn zaps(&self) -> Result<Option<ZapDataV1>, Error> {
        if self.kind != EventKind::Zap {
            return Ok(None);
        }

        let mut zapped_id: Option<Id> = None;
        let mut zapped_amount: Option<MilliSatoshi> = None;
        let mut zapped_pubkey: Option<PublicKey> = None;

        for tag in self.tags.iter() {
            if let TagV1::Other { tag, data } = tag {
                // Find the bolt11 tag
                if tag != "bolt11" {
                    continue;
                }
                if data.is_empty() {
                    return Err(Error::ZapReceipt("missing bolt11 tag value".to_string()));
                }

                // Extract as an Invoice
                let result = Bolt11Invoice::from_str(&data[0]);
                if let Err(e) = result {
                    return Err(Error::ZapReceipt(format!("bolt11 failed to parse: {}", e)));
                }
                let invoice = result.unwrap();

                // Verify the signature
                if let Err(e) = invoice.check_signature() {
                    return Err(Error::ZapReceipt(format!(
                        "bolt11 signature check failed: {}",
                        e
                    )));
                }

                // Get the public key
                let secpk = match invoice.payee_pub_key() {
                    Some(pubkey) => pubkey.to_owned(),
                    None => invoice.recover_payee_pub_key(),
                };
                let (xonlypk, _) = secpk.x_only_public_key();
                let pubkeybytes = xonlypk.serialize();
                let pubkey = match PublicKey::from_bytes(&pubkeybytes, false) {
                    Ok(pubkey) => pubkey,
                    Err(e) => {
                        return Err(Error::ZapReceipt(format!("payee public key error: {}", e)))
                    }
                };
                zapped_pubkey = Some(pubkey);

                if let Some(u) = invoice.amount_milli_satoshis() {
                    zapped_amount = Some(MilliSatoshi(u));
                } else {
                    return Err(Error::ZapReceipt(
                        "Amount missing from zap receipt".to_string(),
                    ));
                }
            }
            if let TagV1::Event { id, .. } = tag {
                zapped_id = Some(*id);
            }
        }

        if zapped_id.is_none() {
            // This probably means a person was zapped, not a note. So not an error.
            return Ok(None);
        }
        if zapped_amount.is_none() {
            return Err(Error::ZapReceipt("Missing amount".to_string()));
        }
        if zapped_pubkey.is_none() {
            return Err(Error::ZapReceipt("Missing payee public key".to_string()));
        }

        Ok(Some(ZapDataV1 {
            id: zapped_id.unwrap(),
            amount: zapped_amount.unwrap(),
            pubkey: zapped_pubkey.unwrap(),
            provider_pubkey: self.pubkey,
        }))
    }

    /// If this event specifies the client that created it, return that client string
    pub fn client(&self) -> Option<String> {
        for tag in self.tags.iter() {
            if let TagV1::Other { tag, data } = tag {
                if tag == "client" && !data.is_empty() {
                    return Some(data[0].clone());
                }
            }
        }

        None
    }

    /// If this event specifies a subject, return that subject string
    pub fn subject(&self) -> Option<String> {
        for tag in self.tags.iter() {
            if let TagV1::Subject { subject, .. } = tag {
                return Some(subject.clone());
            }
        }

        None
    }

    /// If this event specifies a title, return that title string
    pub fn title(&self) -> Option<String> {
        for tag in self.tags.iter() {
            if let TagV1::Title { title, .. } = tag {
                return Some(title.clone());
            }
        }

        None
    }

    /// If this event specifies a summary, return that summary string
    pub fn summary(&self) -> Option<String> {
        for tag in self.tags.iter() {
            if let TagV1::Other { tag, data } = tag {
                if tag == "summary" && !data.is_empty() {
                    return Some(data[0].clone());
                }
            }
        }

        None
    }

    /// If this event specifies a content warning, return that subject string
    pub fn content_warning(&self) -> Option<String> {
        for tag in self.tags.iter() {
            if let TagV1::ContentWarning { warning, .. } = tag {
                return Some(warning.clone());
            }
        }

        None
    }

    /// If this is a parameterized event, get the parameter
    pub fn parameter(&self) -> Option<String> {
        if self.kind.is_parameterized_replaceable() {
            for tag in self.tags.iter() {
                if let TagV1::Identifier { d, .. } = tag {
                    return Some(d.to_owned());
                }
            }
            Some("".to_owned()) // implicit
        } else {
            None
        }
    }

    /// Return all the hashtags this event refers to
    pub fn hashtags(&self) -> Vec<String> {
        if !self.kind.is_feed_displayable() {
            return vec![];
        }

        let mut output: Vec<String> = Vec::new();

        for tag in self.tags.iter() {
            if let TagV1::Hashtag { hashtag, .. } = tag {
                output.push(hashtag.clone());
            }
        }

        output
    }

    /// Return all the URLs this event refers to
    pub fn urls(&self) -> Vec<RelayUrl> {
        if !self.kind.is_feed_displayable() {
            return vec![];
        }

        let mut output: Vec<RelayUrl> = Vec::new();

        for tag in self.tags.iter() {
            if let TagV1::Reference { url, .. } = tag {
                if let Ok(relay_url) = RelayUrl::try_from_unchecked_url(url) {
                    output.push(relay_url);
                }
            }
        }

        output
    }

    /// Get the proof-of-work count of leading bits
    pub fn pow(&self) -> u8 {
        // Count leading bits in the Id field
        let zeroes: u8 = crate::get_leading_zero_bits(&self.id.0);

        // Check that they meant it
        let mut target_zeroes: u8 = 0;
        for tag in self.tags.iter() {
            if let TagV1::Nonce { target, .. } = tag {
                if let Some(t) = target {
                    target_zeroes = t.parse::<u8>().unwrap_or(0);
                }
                break;
            }
        }

        zeroes.min(target_zeroes)
    }

    /// Was this event delegated, was that valid, and if so what is the pubkey of
    /// the delegator?
    pub fn delegation(&self) -> EventDelegation {
        for tag in self.tags.iter() {
            if let TagV1::Delegation {
                pubkey,
                conditions,
                sig,
                ..
            } = tag
            {
                // Convert hex strings into functional types
                let signature = match Signature::try_from_hex_string(sig) {
                    Ok(sig) => sig,
                    Err(e) => return EventDelegation::InvalidDelegation(format!("{e}")),
                };
                let delegator_pubkey = match PublicKey::try_from_hex_string(pubkey, true) {
                    Ok(pk) => pk,
                    Err(e) => return EventDelegation::InvalidDelegation(format!("{e}")),
                };

                // Verify the delegation tag
                match conditions.verify_signature(&delegator_pubkey, &self.pubkey, &signature) {
                    Ok(_) => {
                        // Check conditions
                        if let Some(kind) = conditions.kind {
                            if self.kind != kind {
                                return EventDelegation::InvalidDelegation(
                                    "Event Kind not delegated".to_owned(),
                                );
                            }
                        }
                        if let Some(created_after) = conditions.created_after {
                            if self.created_at < created_after {
                                return EventDelegation::InvalidDelegation(
                                    "Event created before delegation started".to_owned(),
                                );
                            }
                        }
                        if let Some(created_before) = conditions.created_before {
                            if self.created_at > created_before {
                                return EventDelegation::InvalidDelegation(
                                    "Event created after delegation ended".to_owned(),
                                );
                            }
                        }
                        return EventDelegation::DelegatedBy(delegator_pubkey);
                    }
                    Err(e) => {
                        return EventDelegation::InvalidDelegation(format!("{e}"));
                    }
                }
            }
        }

        EventDelegation::NotDelegated
    }

    /// If the event came through a proxy, get the (Protocol, Id)
    pub fn proxy(&self) -> Option<(&str, &str)> {
        for t in self.tags.iter() {
            if let TagV1::Other { tag, data } = t {
                if tag == "proxy" && data.len() >= 2 {
                    return Some((&data[1], &data[0]));
                }
            }
        }
        None
    }
}

// Direct access into speedy-serialized bytes, to avoid alloc-deserialize just to peek
// at one of these fields
#[cfg(feature = "speedy")]
impl EventV1 {
    /// Read the ID of the event from a speedy encoding without decoding
    /// (zero allocation)
    ///
    /// Note this function is fragile, if the Event structure is reordered,
    /// or if speedy code changes, this will break.  Neither should happen.
    pub fn get_id_from_speedy_bytes(bytes: &[u8]) -> Option<Id> {
        if bytes.len() < 32 {
            None
        } else if let Ok(arr) = <[u8; 32]>::try_from(&bytes[0..32]) {
            Some(unsafe { std::mem::transmute(arr) })
        } else {
            None
        }
    }

    /// Read the pubkey of the event from a speedy encoding without decoding
    /// (close to zero allocation, VerifyingKey does stuff I didn't check)
    ///
    /// Note this function is fragile, if the Event structure is reordered,
    /// or if speedy code changes, this will break.  Neither should happen.
    pub fn get_pubkey_from_speedy_bytes(bytes: &[u8]) -> Option<PublicKey> {
        if bytes.len() < 64 {
            None
        } else {
            PublicKey::from_bytes(&bytes[32..64], false).ok()
        }
    }

    /// Read the created_at of the event from a speedy encoding without decoding
    /// (zero allocation)
    ///
    /// Note this function is fragile, if the Event structure is reordered,
    /// or if speedy code changes, this will break.  Neither should happen.
    pub fn get_created_at_from_speedy_bytes(bytes: &[u8]) -> Option<Unixtime> {
        if bytes.len() < 72 {
            None
        } else if let Ok(i) = i64::read_from_buffer(&bytes[64..72]) {
            Some(Unixtime(i))
        } else {
            None
        }
    }

    /// Read the kind of the event from a speedy encoding without decoding
    /// (zero allocation)
    ///
    /// Note this function is fragile, if the Event structure is reordered,
    /// or if speedy code changes, this will break.  Neither should happen.
    pub fn get_kind_from_speedy_bytes(bytes: &[u8]) -> Option<EventKind> {
        if bytes.len() < 76 {
            None
        } else if let Ok(u) = u32::read_from_buffer(&bytes[72..76]) {
            Some(u.into())
        } else {
            None
        }
    }

    // Read the sig of the event from a speedy encoding without decoding
    // (offset would be 76..140

    /// Read the ots of the event from a speedy encoding without decoding
    /// (zero allocation)
    ///
    /// Note this function is fragile, if the Event structure is reordered,
    /// or if speedy code changes, this will break.  Neither should happen.
    pub fn get_ots_from_speedy_bytes(bytes: &[u8]) -> Option<&str> {
        #[allow(clippy::if_same_then_else)]
        if bytes.len() < 140 {
            None
        } else if bytes[140] == 0 {
            None
        } else if bytes.len() < 145 {
            None
        } else {
            let len = u32::from_ne_bytes(bytes[141..145].try_into().unwrap());
            unsafe {
                Some(std::str::from_utf8_unchecked(
                    &bytes[146..146 + len as usize],
                ))
            }
        }
    }

    /// Read the content of the event from a speedy encoding without decoding
    /// (zero allocation)
    ///
    /// Note this function is fragile, if the Event structure is reordered,
    /// or if speedy code changes, this will break.  Neither should happen.
    pub fn get_content_from_speedy_bytes(bytes: &[u8]) -> Option<&str> {
        let start = if bytes.len() < 145 {
            return None;
        } else if bytes[140] == 0 {
            141
        } else {
            // get OTS length and move past it
            let len = u32::from_ne_bytes(bytes[141..145].try_into().unwrap());
            141 + 4 + len as usize
        };

        let len = u32::from_ne_bytes(bytes[start..start + 4].try_into().unwrap());

        unsafe {
            Some(std::str::from_utf8_unchecked(
                &bytes[start + 4..start + 4 + len as usize],
            ))
        }
    }

    /// Check if any human-readable tag matches the Regex in the speedy encoding
    /// without decoding the whole thing (because our Tag representation is so complicated,
    /// we do deserialize the tags for now)
    ///
    /// Note this function is fragile, if the Event structure is reordered,
    /// or if speedy code changes, this will break.  Neither should happen.
    pub fn tag_search_in_speedy_bytes(bytes: &[u8], re: &Regex) -> Result<bool, Error> {
        if bytes.len() < 145 {
            return Ok(false);
        }

        // skip OTS
        let mut offset = if bytes[140] == 0 {
            141
        } else {
            // get OTS length and move past it
            let len = u32::from_ne_bytes(bytes[141..145].try_into().unwrap());
            141 + 4 + len as usize
        };

        // skip content
        let len = u32::from_ne_bytes(bytes[offset..offset + 4].try_into().unwrap());
        offset += 4 + len as usize;

        // Deserialize the tags
        let tags: Vec<TagV1> = Vec::<TagV1>::read_from_buffer(&bytes[offset..])?;

        // Search through them
        for tag in &tags {
            match tag {
                TagV1::ContentWarning { warning, .. } => {
                    if re.is_match(warning.as_ref()) {
                        return Ok(true);
                    }
                }
                TagV1::Hashtag { hashtag, .. } => {
                    if re.is_match(hashtag.as_ref()) {
                        return Ok(true);
                    }
                }
                TagV1::Subject { subject, .. } => {
                    if re.is_match(subject.as_ref()) {
                        return Ok(true);
                    }
                }
                TagV1::Title { title, .. } => {
                    if re.is_match(title.as_ref()) {
                        return Ok(true);
                    }
                }
                TagV1::Other { tag, data } => {
                    if tag == "summary" && !data.is_empty() && re.is_match(data[0].as_ref()) {
                        return Ok(true);
                    }
                }
                _ => {}
            }
        }

        Ok(false)
    }
}

impl From<EventV1> for RumorV1 {
    fn from(e: EventV1) -> RumorV1 {
        RumorV1 {
            id: e.id,
            pubkey: e.pubkey,
            created_at: e.created_at,
            kind: e.kind,
            content: e.content,
            tags: e.tags,
        }
    }
}

impl From<RumorV1> for PreEventV1 {
    fn from(r: RumorV1) -> PreEventV1 {
        PreEventV1 {
            pubkey: r.pubkey,
            created_at: r.created_at,
            kind: r.kind,
            content: r.content,
            tags: r.tags,
        }
    }
}

impl TryFrom<PreEventV1> for RumorV1 {
    type Error = Error;
    fn try_from(e: PreEventV1) -> Result<RumorV1, Error> {
        RumorV1::new(e)
    }
}