Initial commit

db/orm.js

@@ -0,0 +1,189 @@
+// @ts-check
+
+const {db} = require("../passthrough")
+const U = require("./orm-defs")
+
+/**
+ * @template {keyof U.Models} Table
+ * @template {keyof U.Models[Table]} Col
+ * @param {Table} table
+ * @param {Col[] | Col} cols
+ * @param {Partial<U.ValueOrArray<U.Numberish<U.Models[Table]>>>} where
+ * @param {string} [e]
+ */
+function select(table, cols, where = {}, e = "") {
+	if (!Array.isArray(cols)) cols = [cols]
+	const parameters = []
+	const wheres = Object.entries(where).map(([col, value]) => {
+		if (Array.isArray(value)) {
+			parameters.push(...value)
+			return `"${col}" IN (` + Array(value.length).fill("?").join(", ") + ")"
+		} else {
+			parameters.push(value)
+			return `"${col}" = ?`
+		}
+	})
+	const whereString = wheres.length ? " WHERE " + wheres.join(" AND ") : ""
+	/** @type {U.Prepared<Pick<U.Models[Table], Col>>} */
+	const prepared = db.prepare(`SELECT ${cols.map(k => `"${String(k)}"`).join(", ")} FROM ${table} ${whereString} ${e}`)
+	prepared.get = prepared.get.bind(prepared, ...parameters)
+	prepared.all = prepared.all.bind(prepared, ...parameters)
+	return prepared
+}
+
+/**
+ * @template {keyof U.Models} Table
+ * @template {keyof U.Merge<U.Models[Table]>} Col
+ */
+class From {
+	/**
+	 * @param {Table} table
+	 */
+	constructor(table) {
+		/** @private @type {Table[]} */
+		this.tables = [table]
+		/** @private */
+		this.directions = []
+		/** @private */
+		this.sql = ""
+		/** @private */
+		this.cols = []
+		/** @private */
+		this.makeColsSafe = true
+		/** @private */
+		this.using = []
+		/** @private */
+		this.isPluck = false
+		/** @private */
+		this.parameters = []
+	}
+
+	/**
+	 * @template {keyof U.Models} Table2
+	 * @param {Table2} table
+	 * @param {Col & (keyof U.Models[Table2])} col
+	 * @param {"inner" | "left"} [direction]
+	 */
+	join(table, col, direction = "inner") {
+		/** @type {From<Table | Table2, keyof U.Merge<U.Models[Table | Table2]>>} */
+		// @ts-ignore
+		const r = this
+		r.tables.push(table)
+		r.directions.push(direction.toUpperCase())
+		r.using.push(col)
+		return r
+	}
+
+	/**
+	 * @template {Col} Select
+	 * @param {Col[] | Select[]} cols
+	 */
+	select(...cols) {
+		/** @type {From<Table, Select>} */
+		const r = this
+		r.cols = cols
+		return r
+	}
+
+	selectUnsafe(...cols) {
+		this.cols = cols
+		this.makeColsSafe = false
+		return this
+	}
+
+	/**
+	 * @template {Col} Select
+	 * @param {Select} col
+	 */
+	pluck(col) {
+		/** @type {Pluck<Table, Select>} */
+		// @ts-ignore
+		const r = this
+		r.cols = [col]
+		r.isPluck = true
+		return r
+	}
+
+	/**
+	 * @param {string} sql
+	 */
+	and(sql) {
+		this.sql += " " + sql
+		return this
+	}
+
+	/**
+	 * @param {Partial<U.Numberish<U.Models[Table]>>} conditions
+	 */
+	where(conditions) {
+		const wheres = Object.entries(conditions).map(([col, value]) => {
+			this.parameters.push(value)
+			return `"${col}" = ?`
+		})
+		this.sql += " WHERE " + wheres.join(" AND ")
+		return this
+	}
+
+	prepare() {
+		if (this.makeColsSafe) this.cols = this.cols.map(k => `"${k}"`)
+		let sql = `SELECT ${this.cols.join(", ")} FROM ${this.tables[0]} `
+		for (let i = 1; i < this.tables.length; i++) {
+			const table = this.tables[i]
+			const col = this.using[i-1]
+			const direction = this.directions[i-1]
+			sql += `${direction} JOIN ${table} USING (${col}) `
+		}
+		sql += this.sql
+		/** @type {U.Prepared<Pick<U.Merge<U.Models[Table]>, Col>>} */
+		let prepared = db.prepare(sql)
+		if (this.isPluck) prepared = prepared.pluck()
+		return prepared
+	}
+
+	get(..._) {
+		const prepared = this.prepare()
+		return prepared.get(...this.parameters, ..._)
+	}
+
+	all(..._) {
+		const prepared = this.prepare()
+		return prepared.all(...this.parameters, ..._)
+	}
+}
+
+/* c8 ignore start - this code is only used for types and does not actually execute */
+/**
+ * @template {keyof U.Models} Table
+ * @template {keyof U.Merge<U.Models[Table]>} Col
+ */
+class Pluck extends From {
+	// @ts-ignore
+	prepare() {
+		/** @type {U.Prepared<U.Merge<U.Models[Table]>[Col]>} */
+		// @ts-ignore
+		const prepared = super.prepare()
+		return prepared
+	}
+
+	get(..._) {
+		const prepared = this.prepare()
+		return prepared.get(..._)
+	}
+
+	all(..._) {
+		const prepared = this.prepare()
+		return prepared.all(..._)
+	}
+}
+/* c8 ignore stop */
+
+/**
+ * @template {keyof U.Models} Table
+ * @param {Table} table
+ */
+function from(table) {
+	return new From(table)
+}
+
+module.exports.from = from
+module.exports.select = select