linear-api 0.1.0

//! Issue labels: listing, create/update/delete, and the
//! [`LabelsService::ensure`] find-or-create convenience.

use bon::Builder;
use futures::Stream;
use serde::{Deserialize, Serialize};

use crate::client::LinearClient;
use crate::error::{Error, LinearErrorType, Result};
use crate::filter::{IdComparator, IssueLabelFilter, StringComparator, TeamFilter};
use crate::ids::{LabelId, TeamId};
use crate::pagination::{Page, PageInfo, paginate};
use crate::types::{LabelRef, TeamRef, Undefinable, ensure_success};

/// Appends the label fragments to an operation. The `LabelRefFields` and
/// `TeamRefFields` texts are the canonical fragments from `src/types.rs`.
macro_rules! doc_with_label_fields {
    ($op:literal) => {
        concat!(
            $op,
            " fragment LabelFields on IssueLabel { id name color description isGroup \
             parent { ...LabelRefFields } team { ...TeamRefFields } }",
            " fragment LabelRefFields on IssueLabel { id name color }",
            " fragment TeamRefFields on Team { id key name }"
        )
    };
}

const LABEL_LIST: &str = doc_with_label_fields!(
    "query LabelList($filter: IssueLabelFilter, $first: Int, $after: String) { \
     issueLabels(filter: $filter, first: $first, after: $after) { \
     nodes { ...LabelFields } \
     pageInfo { hasNextPage hasPreviousPage startCursor endCursor } } }"
);

const LABEL_CREATE: &str = doc_with_label_fields!(
    "mutation LabelCreate($input: IssueLabelCreateInput!) { \
     issueLabelCreate(input: $input) { success issueLabel { ...LabelFields } } }"
);

const LABEL_UPDATE: &str = doc_with_label_fields!(
    "mutation LabelUpdate($id: String!, $input: IssueLabelUpdateInput!) { \
     issueLabelUpdate(id: $id, input: $input) { success issueLabel { ...LabelFields } } }"
);

const LABEL_DELETE: &str =
    "mutation LabelDelete($id: String!) { issueLabelDelete(id: $id) { success } }";

pub(crate) const DOCUMENTS: &[(&str, &str)] = &[
    ("LabelList", LABEL_LIST),
    ("LabelCreate", LABEL_CREATE),
    ("LabelUpdate", LABEL_UPDATE),
    ("LabelDelete", LABEL_DELETE),
];

/// An issue label.
///
/// `team == None` means the label is a **workspace-level** label, available
/// to every team; otherwise it is scoped to the given team.
///
/// Wire fragment:
/// `fragment LabelFields on IssueLabel { id name color description isGroup
/// parent { ...LabelRefFields } team { ...TeamRefFields } }`
#[derive(Debug, Clone, Deserialize)]
#[serde(rename_all = "camelCase")]
#[non_exhaustive]
pub struct Label {
    /// Label ID.
    pub id: LabelId,
    /// Label name.
    pub name: String,
    /// Label color as a hex string, e.g. `"#BB87FC"`.
    pub color: String,
    /// Optional description.
    pub description: Option<String>,
    /// Whether the label is a group (a container for child labels).
    pub is_group: bool,
    /// The group this label belongs to, when nested.
    pub parent: Option<LabelRef>,
    /// The owning team; `None` for workspace-level labels.
    pub team: Option<TeamRef>,
}

/// Variables for [`LabelsService::list`].
///
/// # Example
///
/// ```no_run
/// # async fn run() -> linear_api::Result<()> {
/// use linear_api::labels::ListLabelsRequest;
///
/// let client = linear_api::LinearClient::from_env()?;
/// let page = client
///     .labels()
///     .list(ListLabelsRequest::builder().first(10).build())
///     .await?;
/// # Ok(()) }
/// ```
#[derive(Debug, Clone, Default, Serialize, Builder)]
#[serde(rename_all = "camelCase")]
#[non_exhaustive]
pub struct ListLabelsRequest {
    /// Filter the returned labels.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub filter: Option<IssueLabelFilter>,
    /// Page size (server default 50). Page size multiplies query complexity;
    /// prefer modest values.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub first: Option<i32>,
    /// Cursor to paginate forward from (a previous page's `end_cursor`).
    #[serde(skip_serializing_if = "Option::is_none")]
    #[builder(into)]
    pub after: Option<String>,
}

/// Input for [`LabelsService::create`] (`IssueLabelCreateInput`).
///
/// # Example
///
/// ```no_run
/// # async fn run() -> linear_api::Result<()> {
/// use linear_api::TeamId;
/// use linear_api::labels::LabelCreateInput;
///
/// let client = linear_api::LinearClient::from_env()?;
/// let label = client
///     .labels()
///     .create(
///         LabelCreateInput::builder()
///             .name("bug")
///             .color("#BB87FC")
///             .team_id(TeamId::new("9c2c88a6-99d3-4a63-a201-8ee5c7dcc374"))
///             .build(),
///     )
///     .await?;
/// # Ok(()) }
/// ```
#[derive(Debug, Clone, Serialize, Builder)]
#[serde(rename_all = "camelCase")]
#[non_exhaustive]
pub struct LabelCreateInput {
    /// Label name (required).
    #[builder(into)]
    pub name: String,
    /// Label color as a hex string like `"#BB87FC"`. Server-assigned when
    /// omitted.
    #[serde(skip_serializing_if = "Option::is_none")]
    #[builder(into)]
    pub color: Option<String>,
    /// Optional description.
    #[serde(skip_serializing_if = "Option::is_none")]
    #[builder(into)]
    pub description: Option<String>,
    /// Owning team. `None` creates a **workspace-level** label.
    #[serde(skip_serializing_if = "Option::is_none")]
    #[builder(into)]
    pub team_id: Option<TeamId>,
    /// Parent group to nest the label under.
    #[serde(skip_serializing_if = "Option::is_none")]
    #[builder(into)]
    pub parent_id: Option<LabelId>,
    /// Whether the label is a group.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub is_group: Option<bool>,
}

/// Input for [`LabelsService::update`] (`IssueLabelUpdateInput`).
///
/// `description` and `parent_id` are clearable: [`Undefinable::Undefined`]
/// (the default) leaves the field unchanged, [`Undefinable::Null`] clears it,
/// and a value sets it.
///
/// # Example
///
/// ```no_run
/// # async fn run() -> linear_api::Result<()> {
/// use linear_api::{LabelId, Undefinable};
/// use linear_api::labels::LabelUpdateInput;
///
/// let client = linear_api::LinearClient::from_env()?;
/// let label = client
///     .labels()
///     .update(
///         &LabelId::new("3d5a8ea4-9e4b-4caf-8d6f-1d914a518790"),
///         LabelUpdateInput::builder()
///             .name("triage")
///             .description(Undefinable::Null) // clear the description
///             .build(),
///     )
///     .await?;
/// # Ok(()) }
/// ```
#[derive(Debug, Clone, Default, Serialize, Builder)]
#[serde(rename_all = "camelCase")]
#[non_exhaustive]
pub struct LabelUpdateInput {
    /// New label name.
    #[serde(skip_serializing_if = "Option::is_none")]
    #[builder(into)]
    pub name: Option<String>,
    /// New color as a hex string like `"#BB87FC"`.
    #[serde(skip_serializing_if = "Option::is_none")]
    #[builder(into)]
    pub color: Option<String>,
    /// Description: set, clear (`Null`), or leave unchanged (`Undefined`).
    #[serde(skip_serializing_if = "Undefinable::is_undefined", default)]
    #[builder(default, into)]
    pub description: Undefinable<String>,
    /// Parent group: set, clear (`Null`), or leave unchanged (`Undefined`).
    #[serde(skip_serializing_if = "Undefinable::is_undefined", default)]
    #[builder(default, into)]
    pub parent_id: Undefinable<LabelId>,
}

/// The `IssueLabelPayload` shape shared by the create and update mutations.
#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
struct LabelPayload {
    success: bool,
    issue_label: Option<Label>,
}

fn unwrap_payload(operation: &'static str, payload: LabelPayload) -> Result<Label> {
    ensure_success(operation, payload.success)?;
    payload.issue_label.ok_or(Error::MissingData { operation })
}

/// `true` for the create-failure shapes a concurrent duplicate produces: an
/// [`Error::Api`] mentioning a duplicate or typed `InvalidInput`.
fn create_conflict(err: &Error) -> bool {
    let Error::Api { errors, .. } = err else {
        return false;
    };
    errors
        .iter()
        .any(|e| e.message.to_ascii_lowercase().contains("duplicate"))
        || err.error_types().contains(&LinearErrorType::InvalidInput)
}

/// Issue label operations. Obtain via [`LinearClient::labels`].
#[derive(Clone, Copy)]
pub struct LabelsService<'a> {
    client: &'a LinearClient,
}

impl LinearClient {
    /// Issue label operations: listing, CRUD, and
    /// [find-or-create](LabelsService::ensure).
    ///
    /// # Example
    ///
    /// ```no_run
    /// # async fn run() -> linear_api::Result<()> {
    /// let client = linear_api::LinearClient::from_env()?;
    /// let labels = client.labels().list(Default::default()).await?;
    /// # Ok(()) }
    /// ```
    pub fn labels(&self) -> LabelsService<'_> {
        LabelsService { client: self }
    }
}

impl<'a> LabelsService<'a> {
    /// Fetches one page of issue labels (`issueLabels`).
    ///
    /// # Example
    ///
    /// ```no_run
    /// # async fn run() -> linear_api::Result<()> {
    /// use linear_api::labels::ListLabelsRequest;
    ///
    /// let client = linear_api::LinearClient::from_env()?;
    /// let page = client
    ///     .labels()
    ///     .list(ListLabelsRequest::builder().first(25).build())
    ///     .await?;
    /// for label in &page.nodes {
    ///     println!("{} ({})", label.name, label.color);
    /// }
    /// # Ok(()) }
    /// ```
    pub async fn list(&self, req: ListLabelsRequest) -> Result<Page<Label>> {
        #[derive(Deserialize)]
        #[serde(rename_all = "camelCase")]
        struct Data {
            issue_labels: Connection,
        }
        #[derive(Deserialize)]
        #[serde(rename_all = "camelCase")]
        struct Connection {
            nodes: Vec<Label>,
            page_info: PageInfo,
        }
        let data: Data = self.client.query("LabelList", LABEL_LIST, req).await?;
        Ok(Page {
            nodes: data.issue_labels.nodes,
            page_info: data.issue_labels.page_info,
        })
    }

    /// Lazily streams every label matching the request across pages,
    /// starting from `req.after` when set (see [`paginate`] for the
    /// complexity note).
    ///
    /// # Example
    ///
    /// ```no_run
    /// # async fn run() -> linear_api::Result<()> {
    /// use futures::TryStreamExt;
    ///
    /// let client = linear_api::LinearClient::from_env()?;
    /// let labels = client.labels();
    /// let mut stream = labels.list_stream(Default::default());
    /// futures::pin_mut!(stream);
    /// while let Some(label) = stream.try_next().await? {
    ///     println!("{}", label.name);
    /// }
    /// # Ok(()) }
    /// ```
    pub fn list_stream(&self, req: ListLabelsRequest) -> impl Stream<Item = Result<Label>> + 'a {
        let service = *self;
        paginate(move |cursor| {
            let mut req = req.clone();
            // The first call keeps a caller-seeded `req.after`; later calls
            // advance to each page's end cursor.
            if cursor.is_some() {
                req.after = cursor;
            }
            async move { service.list(req).await }
        })
    }

    /// Creates a label (`issueLabelCreate`).
    ///
    /// # Example
    ///
    /// ```no_run
    /// # async fn run() -> linear_api::Result<()> {
    /// use linear_api::labels::LabelCreateInput;
    ///
    /// let client = linear_api::LinearClient::from_env()?;
    /// // No `team_id`: a workspace-level label.
    /// let label = client
    ///     .labels()
    ///     .create(LabelCreateInput::builder().name("infra").build())
    ///     .await?;
    /// # Ok(()) }
    /// ```
    pub async fn create(&self, input: LabelCreateInput) -> Result<Label> {
        #[derive(Deserialize)]
        #[serde(rename_all = "camelCase")]
        struct Data {
            issue_label_create: LabelPayload,
        }
        let data: Data = self
            .client
            .mutation(
                "LabelCreate",
                LABEL_CREATE,
                serde_json::json!({ "input": input }),
            )
            .await?;
        unwrap_payload("LabelCreate", data.issue_label_create)
    }

    /// Updates a label (`issueLabelUpdate`).
    ///
    /// # Example
    ///
    /// ```no_run
    /// # async fn run() -> linear_api::Result<()> {
    /// use linear_api::{LabelId, Undefinable};
    /// use linear_api::labels::LabelUpdateInput;
    ///
    /// let client = linear_api::LinearClient::from_env()?;
    /// let label = client
    ///     .labels()
    ///     .update(
    ///         &LabelId::new("3d5a8ea4-9e4b-4caf-8d6f-1d914a518790"),
    ///         LabelUpdateInput::builder().color("#26B5CE").build(),
    ///     )
    ///     .await?;
    /// # Ok(()) }
    /// ```
    pub async fn update(&self, id: &LabelId, input: LabelUpdateInput) -> Result<Label> {
        #[derive(Deserialize)]
        #[serde(rename_all = "camelCase")]
        struct Data {
            issue_label_update: LabelPayload,
        }
        let data: Data = self
            .client
            .mutation(
                "LabelUpdate",
                LABEL_UPDATE,
                serde_json::json!({ "id": id, "input": input }),
            )
            .await?;
        unwrap_payload("LabelUpdate", data.issue_label_update)
    }

    /// Deletes a label (`issueLabelDelete`).
    ///
    /// # Example
    ///
    /// ```no_run
    /// # async fn run() -> linear_api::Result<()> {
    /// use linear_api::LabelId;
    ///
    /// let client = linear_api::LinearClient::from_env()?;
    /// client
    ///     .labels()
    ///     .delete(&LabelId::new("3d5a8ea4-9e4b-4caf-8d6f-1d914a518790"))
    ///     .await?;
    /// # Ok(()) }
    /// ```
    pub async fn delete(&self, id: &LabelId) -> Result<()> {
        #[derive(Deserialize)]
        #[serde(rename_all = "camelCase")]
        struct Data {
            issue_label_delete: Payload,
        }
        #[derive(Deserialize)]
        struct Payload {
            success: bool,
        }
        let data: Data = self
            .client
            .mutation("LabelDelete", LABEL_DELETE, serde_json::json!({ "id": id }))
            .await?;
        ensure_success("LabelDelete", data.issue_label_delete.success)
    }

    /// Finds a label by name (case-insensitive) or creates it — the
    /// find-or-create primitive behind "labels found or created on the team"
    /// in plan-apply flows.
    ///
    /// With `team == Some(_)` the lookup is scoped to that team and a created
    /// label is team-scoped. With `team == None` the lookup is
    /// workspace-wide: a workspace-level match (label with no team) is
    /// preferred, any exact-name match is accepted otherwise, and a created
    /// label is workspace-level.
    ///
    /// # Race tolerance
    ///
    /// Linear has no idempotency keys, so two concurrent `ensure` calls can
    /// both miss the lookup and race the create. When the create fails with
    /// a duplicate-name/`InvalidInput` API error, the lookup is re-run once
    /// and the winner's label is returned; if that re-lookup still finds
    /// nothing, the original create error is surfaced.
    ///
    /// # Example
    ///
    /// ```no_run
    /// # async fn run() -> linear_api::Result<()> {
    /// use linear_api::TeamId;
    ///
    /// let client = linear_api::LinearClient::from_env()?;
    /// let team = TeamId::new("9c2c88a6-99d3-4a63-a201-8ee5c7dcc374");
    /// let label = client.labels().ensure(Some(&team), "bug").await?;
    /// # Ok(()) }
    /// ```
    pub async fn ensure(&self, team: Option<&TeamId>, name: &str) -> Result<Label> {
        if let Some(label) = self.find_by_name(team, name).await? {
            return Ok(label);
        }
        let input = LabelCreateInput {
            name: name.to_owned(),
            color: None,
            description: None,
            team_id: team.cloned(),
            parent_id: None,
            is_group: None,
        };
        match self.create(input).await {
            Ok(label) => Ok(label),
            Err(err) if create_conflict(&err) => match self.find_by_name(team, name).await? {
                Some(label) => Ok(label),
                None => Err(err),
            },
            Err(err) => Err(err),
        }
    }

    /// Looks up a label by exact name, case-insensitively. Scoped to `team`
    /// when given; workspace-wide otherwise, preferring a workspace-level
    /// (team-less) match over team-scoped ones.
    async fn find_by_name(&self, team: Option<&TeamId>, name: &str) -> Result<Option<Label>> {
        let filter = IssueLabelFilter {
            name: Some(StringComparator {
                eq_ignore_case: Some(name.to_owned()),
                ..Default::default()
            }),
            team: team.map(|team| TeamFilter {
                id: Some(IdComparator {
                    eq: Some(team.to_string()),
                    ..Default::default()
                }),
                ..Default::default()
            }),
            ..Default::default()
        };
        let page = self
            .list(ListLabelsRequest {
                filter: Some(filter),
                first: None,
                after: None,
            })
            .await?;
        let mut team_scoped_match = None;
        for label in page.nodes {
            // The server filter is already exact-and-case-insensitive; this
            // guard keeps the invariant even if the filter loosens.
            if !label.name.eq_ignore_ascii_case(name) {
                continue;
            }
            if team.is_some() || label.team.is_none() {
                return Ok(Some(label));
            }
            if team_scoped_match.is_none() {
                team_scoped_match = Some(label);
            }
        }
        Ok(team_scoped_match)
    }
}