1 files changed, 478 insertions, 0 deletions
diff --git a/pkg/data/update.go b/pkg/data/update.go
new file mode 100644
index 0000000..a606256
--- /dev/null
+++ b/pkg/data/update.go
@@ -0,0 +1,478 @@
+package data
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+
+	"github.com/jpappel/atlas/pkg/index"
+)
+
+type Update struct {
+	Id  int64
+	Doc index.Document
+	db  *sql.DB
+	tx  *sql.Tx
+}
+
+type UpdateMany struct {
+	Docs     map[int64]*index.Document
+	pathDocs map[string]*index.Document
+	tx       *sql.Tx
+	db       *sql.DB
+}
+
+func NewUpdate(ctx context.Context, db *sql.DB, doc index.Document) Update {
+	return Update{Doc: doc, db: db}
+}
+
+func NewUpdateMany(db *sql.DB, docs map[string]*index.Document) UpdateMany {
+	return UpdateMany{pathDocs: docs, db: db}
+}
+
+// Replace a document if its filetime is newer than the one in the database.
+func (u *Update) Update(ctx context.Context) error {
+	var err error
+	u.tx, err = u.db.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+
+	isUpdate, err := u.document()
+	if !isUpdate || err != nil {
+		u.tx.Rollback()
+		return err
+	}
+
+	if err := u.tags(); err != nil {
+		u.tx.Rollback()
+		return err
+	}
+
+	if err := u.links(); err != nil {
+		u.tx.Rollback()
+		return err
+	}
+
+	if err := u.authors(); err != nil {
+		u.tx.Rollback()
+		return err
+	}
+
+	return u.tx.Commit()
+}
+
+func (u *UpdateMany) Update(ctx context.Context) error {
+	var err error
+	u.tx, err = u.db.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+
+	hasUpdates, err := u.documents()
+	if !hasUpdates || err != nil {
+		u.tx.Rollback()
+		return err
+	}
+
+	if err := u.tags(); err != nil {
+		u.tx.Rollback()
+		return err
+	}
+
+	if err := u.links(); err != nil {
+		u.tx.Rollback()
+		return err
+	}
+
+	if err := u.authors(); err != nil {
+		u.tx.Rollback()
+		return err
+	}
+
+	return u.tx.Commit()
+}
+
+// set document fields in db, returns if an update has occured
+func (u *Update) document() (bool, error) {
+	filetime := sql.NullInt64{Int64: u.Doc.FileTime.Unix(), Valid: !u.Doc.FileTime.IsZero()}
+	row := u.tx.QueryRow(`
+	SELECT TRUE
+	FROM Documents
+	WHERE path = ? AND COALESCE(fileTime,0) < COALESCE(?,0)
+	`, u.Doc.Path, filetime)
+
+	isUpdate := false
+	if err := row.Scan(&isUpdate); err == sql.ErrNoRows {
+		isUpdate = true
+	} else if err != nil {
+		return false, err
+	}
+
+	if !isUpdate {
+		return false, nil
+	}
+
+	title := sql.NullString{String: u.Doc.Title, Valid: u.Doc.Title != ""}
+	date := sql.NullInt64{Int64: u.Doc.Date.Unix(), Valid: !u.Doc.Date.IsZero()}
+	meta := sql.NullString{String: u.Doc.OtherMeta, Valid: u.Doc.OtherMeta != ""}
+
+	_, err := u.tx.Exec(`
+	INSERT INTO Documents(path, title, date, fileTime, meta)
+	VALUES (?,?,?,?,?)
+	ON CONFLICT(path)
+	DO UPDATE SET
+		title=excluded.title,
+		date=excluded.date,
+		fileTime=excluded.fileTime,
+		meta=excluded.meta
+	`, u.Doc.Path, title, date, filetime, meta)
+	if err != nil {
+		return true, err
+	}
+
+	row = u.tx.QueryRow(`SELECT id FROM Documents WHERE path = ?`, u.Doc.Path)
+	if err := row.Scan(&u.Id); err != nil {
+		return true, err
+	}
+
+	return true, nil
+}
+
+func (u *UpdateMany) documents() (bool, error) {
+	_, err := u.tx.Exec(`
+	CREATE TEMPORARY TABLE updateDocs (
+		path TEXT UNIQUE NOT NULL,
+		title TEXT,
+		date INT,
+		fileTime INT,
+		meta BLOB
+	)`)
+	if err != nil {
+		return false, err
+	}
+	defer u.tx.Exec("DROP TABLE temp.updateDocs")
+
+	tempInsertStmt, err := u.tx.Prepare("INSERT INTO temp.updateDocs VALUES (?,?,?,?,?)")
+	if err != nil {
+		return false, err
+	}
+	defer tempInsertStmt.Close()
+
+	for path, doc := range u.pathDocs {
+		filetime := sql.NullInt64{
+			Int64: doc.FileTime.Unix(),
+			Valid: !doc.FileTime.IsZero(),
+		}
+		title := sql.NullString{
+			String: doc.Title,
+			Valid:  doc.Title != "",
+		}
+		date := sql.NullInt64{
+			Int64: doc.Date.Unix(),
+			Valid: !doc.Date.IsZero(),
+		}
+		meta := sql.NullString{
+			String: doc.OtherMeta,
+			Valid:  doc.OtherMeta != "",
+		}
+		if _, err := tempInsertStmt.Exec(path, title, date, filetime, meta); err != nil {
+			return false, err
+		}
+	}
+
+	_, err = u.tx.Exec(`
+	DELETE FROM Documents
+	WHERE Documents.path NOT IN (
+		SELECT path FROM temp.updateDocs
+	)`)
+	if err != nil {
+		return false, err
+	}
+
+	_, err = u.tx.Exec(`
+	INSERT INTO Documents (path, title, date, fileTime, meta)
+	SELECT * FROM updateDocs WHERE TRUE
+	ON CONFLICT(path) DO UPDATE SET
+		title=excluded.title,
+		date=excluded.date,
+		fileTime=excluded.fileTime,
+		meta=excluded.meta
+	WHERE excluded.fileTime > Documents.fileTime
+	`)
+	if err != nil {
+		return false, err
+	}
+
+	updates, err := u.tx.Query(`
+	SELECT id, Documents.path
+	FROM updateDocs
+	JOIN Documents ON updateDocs.path = Documents.path
+	WHERE Documents.fileTime = updateDocs.fileTime
+	`)
+	if err != nil {
+		return false, err
+	}
+	defer updates.Close()
+
+	u.Docs = make(map[int64]*index.Document)
+	var id int64
+	var path string
+	hasUpdate := false
+	for updates.Next() {
+		if err := updates.Scan(&id, &path); err != nil {
+			return false, err
+		}
+		u.Docs[id] = u.pathDocs[path]
+		hasUpdate = true
+	}
+
+	return hasUpdate, nil
+}
+
+func (u Update) tags() error {
+	if _, err := u.tx.Exec(`
+	DELETE FROM DocumentTags
+	WHERE docId = ?
+	`, u.Id); err != nil {
+		return err
+	}
+
+	query, args := BatchQuery(
+		"INSERT OR IGNORE INTO Tags (name) VALUES",
+		"", "(?)", ",", "",
+		len(u.Doc.Tags), u.Doc.Tags,
+	)
+	if _, err := u.tx.Exec(query, args...); err != nil {
+		return err
+	}
+
+	preqQuery := fmt.Sprintf(`
+	INSERT INTO DocumentTags
+		SELECT %d, Tags.id
+		FROM Tags
+		WHERE name in
+	`, u.Id)
+	query, args = BatchQuery(
+		preqQuery, "(", "?", ",", ")",
+		len(u.Doc.Tags), u.Doc.Tags,
+	)
+
+	if _, err := u.tx.Exec(query, args...); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (u UpdateMany) tags() error {
+	// PERF: consider batching
+	deleteStmt, err := u.tx.Prepare("DELETE FROM DocumentTags WHERE docId = ?")
+	if err != nil {
+		return err
+	}
+	defer deleteStmt.Close()
+
+	for id := range u.Docs {
+		if _, err := deleteStmt.Exec(id); err != nil {
+			return err
+		}
+	}
+
+	for id, doc := range u.Docs {
+		if len(doc.Tags) == 0 {
+			continue
+		}
+		insertTag, args := BatchQuery(
+			"INSERT OR IGNORE INTO Tags (name) VALUES",
+			"", "(?)", ",", "",
+			len(doc.Tags), doc.Tags,
+		)
+		_, err = u.tx.Exec(insertTag, args...)
+		if err != nil {
+			return err
+		}
+
+		preqQuery := fmt.Sprintf(`
+		INSERT INTO DocumentTags
+			SELECT %d, Tags.id
+			FROM Tags
+			WHERE name in
+		`, id)
+		setDocTags, _ := BatchQuery(
+			preqQuery, "(", "?", ",", ")",
+			len(doc.Tags), doc.Tags,
+		)
+		if _, err := u.tx.Exec(setDocTags, args...); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (u Update) links() error {
+	if _, err := u.tx.Exec(`
+	DELETE FROM Links
+	WHERE docId = ?
+	`, u.Id); err != nil {
+		return err
+	}
+
+	query, args := BatchQuery(
+		"INSERT INTO Links VALUES ",
+		"", fmt.Sprintf("(%d,?)", u.Id), ",", "",
+		len(u.Doc.Links), u.Doc.Links,
+	)
+	if _, err := u.tx.Exec(query, args...); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (u UpdateMany) links() error {
+	deleteStmt, err := u.tx.Prepare("DELETE FROM Links WHERE docId = ?")
+	if err != nil {
+		return err
+	}
+	defer deleteStmt.Close()
+	insertStmt, err := u.tx.Prepare("INSERT OR IGNORE INTO Links VALUES (?,?)")
+	if err != nil {
+		return err
+	}
+	defer insertStmt.Close()
+
+	for id, doc := range u.Docs {
+		if _, err := deleteStmt.Exec(id); err != nil {
+			return err
+		}
+
+		for _, link := range doc.Links {
+			if _, err := insertStmt.Exec(id, link); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (u Update) authors() error {
+	if _, err := u.tx.Exec(`
+	DELETE FROM DocumentAuthors
+	WHERE docId = ?
+	`, u.Id); err != nil {
+		return err
+	}
+
+	tempTable, args := BatchQuery(`
+		CREATE TEMPORARY TABLE new_names AS
+		SELECT column1 AS name
+		FROM ( VALUES `,
+		"", "(?)", ",", ")",
+		len(u.Doc.Authors), u.Doc.Authors,
+	)
+	_, err := u.tx.Exec(tempTable, args...)
+	if err != nil {
+		return err
+	}
+	defer u.tx.Exec("DROP TABLE temp.new_names")
+
+	_, err = u.tx.Exec(`
+	INSERT OR IGNORE INTO Authors(name)
+	SELECT * FROM new_names
+	`)
+	if err != nil {
+		return err
+	}
+	_, err = u.tx.Exec(`
+	INSERT OR IGNORE INTO Aliases(alias)
+	SELECT * FROM new_names
+	`)
+	if err != nil {
+		return err
+	}
+
+	docAuthQuery := fmt.Sprintf(`
+	INSERT INTO DocumentAuthors
+	SELECT %d, existing.id
+	FROM new_names
+	LEFT JOIN (
+		SELECT * FROM Authors
+		UNION ALL
+		SELECT * FROM Aliases
+	) AS existing ON existing.name = new_names.name
+	`, u.Id)
+	if _, err := u.tx.Exec(docAuthQuery); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (u UpdateMany) authors() error {
+	deleteStmt, err := u.tx.Prepare("DELETE FROM DocumentAuthors WHERE docId = ?")
+	if err != nil {
+		return err
+	}
+	defer deleteStmt.Close()
+
+	_, err = u.tx.Exec(`
+	CREATE TEMPORARY TABLE new_names (
+		docId INTEGER NOT NULL,
+		name TEXT NOT NULL,
+		UNIQUE(docId, name)
+	)`)
+	if err != nil {
+		return err
+	}
+	defer u.tx.Exec("DROP TABLE temp.new_names")
+
+	insertTempTable, err := u.tx.Prepare("INSERT INTO temp.new_names VALUES (?,?)")
+	if err != nil {
+		return err
+	}
+	defer insertTempTable.Close()
+
+	for id, doc := range u.Docs {
+		if _, err := deleteStmt.Exec(id); err != nil {
+			return err
+		}
+
+		for _, author := range doc.Authors {
+			if _, err := insertTempTable.Exec(id, author); err != nil {
+				return err
+			}
+		}
+	}
+
+	_, err = u.tx.Exec(`
+	INSERT OR IGNORE INTO Authors(name)
+	SELECT name FROM new_names
+	`)
+	if err != nil {
+		return err
+	}
+
+	_, err = u.tx.Exec(`
+	INSERT OR IGNORE INTO Aliases(alias)
+	SELECT name FROM new_names
+	`)
+	if err != nil {
+		return err
+	}
+
+	_, err = u.tx.Exec(`
+	INSERT INTO DocumentAuthors
+	SELECT docId, existing.id
+	FROM new_names
+	LEFT JOIN (
+	SELECT * FROM Authors
+	UNION ALL
+	SELECT * FROM Aliases
+	) AS existing ON existing.name = new_names.name
+	`)
+
+	return err
+}