//! Types of the Oxygenhub JSON API (hub spec §12.1). Everything here is
//! `serde` data with no behaviour, so clients in other languages can be
//! generated from it and the server can never drift from them.
//!
//! Shapes reuse `oxy --json`'s where one exists (hashes as lowercase hex,
//! times as milliseconds since the epoch), so tools written against the
//! command line work against the hub.

use serde::{Deserialize, Serialize};

/// A repository as the API lists it.
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
pub struct Repository {
    pub owner: String,
    pub name: String,
    pub description: String,
    pub default_bookmark: String,
    pub visibility: Visibility,
    /// Milliseconds since the epoch.
    pub created_ms: i64,
    pub updated_ms: i64,
    /// `https://…/{owner}/{name}`, what `oxy clone` takes.
    pub clone_url: String,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "lowercase")]
pub enum Visibility {
    Public,
    Internal,
    Private,
}

impl Visibility {
    pub fn as_str(self) -> &'static str {
        match self {
            Visibility::Public => "public",
            Visibility::Internal => "internal",
            Visibility::Private => "private",
        }
    }

    pub fn parse(s: &str) -> Option<Visibility> {
        Some(match s {
            "public" => Visibility::Public,
            "internal" => Visibility::Internal,
            "private" => Visibility::Private,
            _ => return None,
        })
    }
}

/// A bookmark: a name for a set of heads (spec §10.1).
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
pub struct Bookmark {
    pub name: String,
    pub heads: Vec<String>,
    /// Number of changes in the bookmark's state.
    pub changes: usize,
    pub default: bool,
}

/// A tag: a name for one state, with its attestation when signed.
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
pub struct Tag {
    pub name: String,
    pub heads: Vec<String>,
    pub message: String,
    pub signer: Option<String>,
}

/// One change in a history listing.
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
pub struct ChangeSummary {
    pub hash: String,
    pub message: String,
    pub author: Author,
    pub when_ms: u64,
    pub deps: Vec<String>,
    pub head: bool,
    pub signature: Signature,
}

/// Who wrote a change: the linked account when the signing key is linked,
/// else the key alone.
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
pub struct Author {
    pub name: String,
    pub email: String,
    pub key: String,
    /// The hub account this key is linked to, when any.
    pub account: Option<String>,
}

/// Signature status of a change as `oxy verify` reports it.
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(tag = "status", rename_all = "lowercase")]
pub enum Signature {
    Unsigned,
    Valid { key: String, sealed: bool, revoked: bool },
    Invalid { reason: String },
}

/// An RFC 7807 problem response.
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
pub struct Problem {
    pub status: u16,
    pub title: String,
    pub detail: String,
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn visibility_round_trips() {
        for v in [Visibility::Public, Visibility::Internal, Visibility::Private] {
            assert_eq!(Visibility::parse(v.as_str()), Some(v));
        }
        assert_eq!(Visibility::parse("secret"), None);
    }
}

// ---------------------------------------------------------------- proposals

/// A proposal: a request to add changes to a target bookmark (hub spec §7).
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
pub struct Proposal {
    pub number: i64,
    pub title: String,
    pub body: String,
    pub author: String,
    pub state: ProposalState,
    pub target: String,
    pub source: ProposalSource,
    /// The changes the proposal adds, dependency order, newest last.
    pub changes: Vec<ChangeSummary>,
    /// Heads of the projected state (target plus the changes), when computed.
    pub projected_heads: Vec<String>,
    pub projected_state: Option<String>,
    pub conflicted: bool,
    pub approvals: Vec<Approval>,
    pub landable: bool,
    pub blockers: Vec<String>,
    pub created_ms: i64,
    pub updated_ms: i64,
    /// `https://hub/{owner}/{name}/proposal/{number}`.
    pub url: String,
    /// Where `oxy` fetches the changes from.
    pub repository_url: String,
    /// The fork's clone URL when the source is a fork.
    pub source_url: Option<String>,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "lowercase")]
pub enum ProposalState {
    Draft,
    Open,
    Landed,
    Closed,
}

impl ProposalState {
    pub fn as_str(self) -> &'static str {
        match self {
            ProposalState::Draft => "draft",
            ProposalState::Open => "open",
            ProposalState::Landed => "landed",
            ProposalState::Closed => "closed",
        }
    }

    pub fn parse(s: &str) -> Option<ProposalState> {
        Some(match s {
            "draft" => ProposalState::Draft,
            "open" => ProposalState::Open,
            "landed" => ProposalState::Landed,
            "closed" => ProposalState::Closed,
            _ => return None,
        })
    }
}

#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(tag = "kind", rename_all = "lowercase")]
pub enum ProposalSource {
    /// A bookmark of the same repository.
    Bookmark { bookmark: String },
    /// A bookmark of a fork.
    Fork { owner: String, name: String, bookmark: String },
    /// An explicit list of change hashes.
    Changes { hashes: Vec<String> },
}

/// A reviewer's approval, counted only when backed by a seal over every
/// change of the proposal signed with a key linked to the reviewer.
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
pub struct Approval {
    pub account: String,
    pub sealed: bool,
    pub key: Option<String>,
}