[WJ-1361] implement PageQueryService::select() with SelectedFields

deepwell/Cargo.toml

@@ -27,6 +27,7 @@ color-backtrace = "0.7"
 cuid2 = "0.1"
 data-encoding = "2"
 dotenvy = "0.15"
+enumset = { version = "1", features = ["serde"] }
 exn = "0.3"
 femme = "2"
 filemagic = "0.13"

deepwell/src/services/page_query/service.rs

@@ -27,6 +27,7 @@ use crate::models::page_connection::{self, Entity as PageConnection};
 use crate::models::page_parent::{self, Entity as PageParent};
 use crate::models::{page_revision, text};
 use crate::services::{PageService, ParentService};
+use crate::utils::get_category_name;
 use sea_query::{Expr, Query};
 
 #[derive(Debug)]
@@ -483,4 +484,107 @@ impl PageQueryService {
 
         Ok(FoundPages { pages: rows })
     }
+
+    /// Takes the output of `find()` and extracts only the fields
+    /// specified in `SelectedFields`, producing a `SelectedPages`
+    /// result with each page's values populated as typed fields.
+    pub fn select(found: FoundPages, fields: SelectedFields) -> Result<SelectedPages> {
+        info!(
+            "Selecting {} fields from {} pages",
+            fields.len(),
+            found.total(),
+        );
+
+        let pages = found
+            .pages
+            .into_iter()
+            .map(|row| SelectedPageRow {
+                page_id: row.page_id,
+                site_id: fields
+                    .contains(SelectedField::SiteId)
+                    .then_some(row.site_id),
+                title: if fields.contains(SelectedField::Title) {
+                    row.title
+                } else {
+                    None
+                },
+                alt_title: if fields.contains(SelectedField::AltTitle) {
+                    row.alt_title
+                } else {
+                    None
+                },
+                slug: if fields.contains(SelectedField::PageSlug)
+                    || fields.contains(SelectedField::FullSlug)
+                {
+                    row.slug.clone()
+                } else {
+                    None
+                },
+                // Extract the category prefix from the slug (e.g. "scp" from "scp:scp-173").
+                category: if fields.contains(SelectedField::Category) {
+                    row.slug.as_deref().map(|s| get_category_name(s).to_owned())
+                } else {
+                    None
+                },
+                created_at: if fields.contains(SelectedField::CreatedAt) {
+                    row.created_at
+                } else {
+                    None
+                },
+                created_by: if fields.contains(SelectedField::CreatedBy) {
+                    row.created_by
+                } else {
+                    None
+                },
+                updated_at: if fields.contains(SelectedField::UpdatedAt) {
+                    row.updated_at
+                } else {
+                    None
+                },
+                updated_by: if fields.contains(SelectedField::UpdatedBy) {
+                    row.updated_by
+                } else {
+                    None
+                },
+                tags: if fields.contains(SelectedField::Tags) {
+                    row.tags.clone()
+                } else {
+                    None
+                },
+                // Hidden tags are those starting with '_'.
+                hidden_tags: if fields.contains(SelectedField::HiddenTags) {
+                    row.tags.as_ref().map(|tags| {
+                        tags.iter()
+                            .filter(|t| t.starts_with('_'))
+                            .cloned()
+                            .collect()
+                    })
+                } else {
+                    None
+                },
+                score: if fields.contains(SelectedField::Score) {
+                    row.score
+                } else {
+                    None
+                },
+                score_votes: None, // TODO: requires vote join
+                revisions: None,   // TODO: requires revision count join
+                comments: None,    // TODO: requires forum post count join
+                children: None,    // TODO: requires page_parent count join
+                size: None,        // TODO: requires text join
+                page_category_id: if fields.contains(SelectedField::PageCategoryId) {
+                    row.page_category_id
+                } else {
+                    None
+                },
+                page_revision_id: if fields.contains(SelectedField::PageRevisionId) {
+                    row.page_revision_id
+                } else {
+                    None
+                },
+            })
+            .collect();
+
+        Ok(SelectedPages { pages })
+    }
 }

deepwell/src/services/page_query/structs.rs

@@ -23,6 +23,7 @@
 
 use super::prelude::*;
 use crate::services::score::ScoreValue;
+use enumset::{EnumSet, EnumSetType};
 use sea_orm::prelude::TimeDateTimeWithTimeZone;
 use std::borrow::Cow;
 use time::OffsetDateTime;
@@ -352,3 +353,102 @@ impl FoundPages {
         self.pages.len()
     }
 }
+
+/// A single field to select from the query results.
+///
+/// Mirrors `PageQueryVariables` but is serializable and
+/// does not carry lifetime parameters.
+#[derive(EnumSetType, Deserialize, Serialize, Debug)]
+#[serde(rename_all = "snake_case")]
+pub enum SelectedField {
+    PageId,
+    SiteId,
+    Title,
+    AltTitle,
+    PageSlug,
+    FullSlug,
+    Category,
+    CreatedAt,
+    CreatedBy,
+    UpdatedAt,
+    UpdatedBy,
+    Tags,
+    HiddenTags,
+    Score,
+    ScoreVotes,
+    Revisions,
+    Comments,
+    Children,
+    Size,
+    PageCategoryId,
+    PageRevisionId,
+}
+
+/// Specifies which display fields the caller wants from the
+/// page query results. Each variant corresponds to a ListPages
+/// output variable like `%%title%%` or `%%created_at%%`.
+pub type SelectedFields = EnumSet<SelectedField>;
+
+/// A single page in the selected output, containing only
+/// the fields requested via `SelectedFields`.
+#[derive(Serialize, Debug, Clone, PartialEq, Default)]
+pub struct SelectedPageRow {
+    pub page_id: i64,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub site_id: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub title: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub alt_title: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub slug: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub category: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(with = "time::serde::rfc3339::option")]
+    pub created_at: Option<TimeDateTimeWithTimeZone>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub created_by: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(with = "time::serde::rfc3339::option")]
+    pub updated_at: Option<TimeDateTimeWithTimeZone>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub updated_by: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tags: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub hidden_tags: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub score: Option<f32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub score_votes: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub revisions: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub comments: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub children: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub size: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub page_category_id: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub page_revision_id: Option<i64>,
+}
+
+/// The result of `PageQueryService::select()`.
+///
+/// Contains the pages in order with exactly the fields
+/// described in the `SelectedFields` input.
+#[derive(Serialize, Debug, Clone, PartialEq)]
+pub struct SelectedPages {
+    pub pages: Vec<SelectedPageRow>,
+}
+
+impl SelectedPages {
+    #[inline]
+    pub fn total(&self) -> usize {
+        self.pages.len()
+    }
+}