Refactor db and local-cache code

Separated cwmp and ui code into distinct files to enhance clarity and
maintainability with varied internal data representations.

lib/db/util.ts

@@ -0,0 +1,123 @@
+import { Expression } from "../types";
+import { encodeTag } from "../util";
+
+// Optimize projection by removing overlaps
+// This can modify the object
+export function optimizeProjection(obj: { [path: string]: 1 }): {
+  [path: string]: 1;
+} {
+  if (obj[""]) return { "": obj[""] };
+
+  const keys = Object.keys(obj).sort();
+  if (keys.length <= 1) return obj;
+
+  for (let i = 1; i < keys.length; ++i) {
+    const a = keys[i - 1];
+    const b = keys[i];
+    if (b.startsWith(a)) {
+      if (b.charAt(a.length) === "." || b.charAt(a.length - 1) === ".") {
+        delete obj[b];
+        keys.splice(i--, 1);
+      }
+    }
+  }
+  return obj;
+}
+
+export function convertOldPrecondition(q: Record<string, unknown>): Expression {
+  function recursive(_query): Expression {
+    const expressions: Expression[] = [];
+    for (const [k, v] of Object.entries(_query)) {
+      if (k[0] === "$") {
+        if (k === "$and") {
+          const and: Expression = ["AND"];
+          for (const vv of Object.values(v)) and.push(recursive(vv));
+          expressions.push(and);
+        } else if (k === "$or") {
+          const or: Expression = ["OR"];
+          for (const vv of Object.values(v)) or.push(recursive(vv));
+          expressions.push(or);
+        } else {
+          throw new Error(`Operator ${k} not supported`);
+        }
+      } else if (k === "_tags") {
+        if (typeof v === "object") {
+          if (Array.isArray(v)) throw new Error(`Invalid type`);
+          const conjs: Expression[] = [];
+          for (const [op, val] of Object.entries(v)) {
+            if (op === "$ne") {
+              if (typeof v["$ne"] !== "string")
+                throw new Error("Only string values are allowed for _tags");
+              conjs.push(["IS NULL", ["PARAM", `Tags.${encodeTag(val)}`]]);
+            } else if (op === "$eq") {
+              if (typeof v["$eq"] !== "string")
+                throw new Error("Only string values are allowed for _tags");
+              conjs.push(["IS NOT NULL", ["PARAM", `Tags.${encodeTag(val)}`]]);
+            } else {
+              throw new Error(`Invalid tag query`);
+            }
+          }
+          if (conjs.length === 1) expressions.push(conjs[0]);
+          else if (conjs.length > 1) expressions.push(["AND", ...conjs]);
+        } else {
+          expressions.push([
+            "IS NOT NULL",
+            ["PARAM", `Tags.${encodeTag(v as string)}`],
+          ]);
+        }
+      } else if (k.startsWith("Tags.")) {
+        let exists: boolean;
+        if (typeof v === "boolean") exists = v;
+        else if (v.hasOwnProperty("$eq")) exists = !!v["$eq"];
+        else if (v.hasOwnProperty("$ne")) exists = !v["$ne"];
+        else if (v.hasOwnProperty("$exists")) exists = !!v["$exists"];
+        else throw new Error(`Invalid tag query`);
+
+        expressions.push([exists ? "IS NOT NULL" : "IS NULL", ["PARAM", k]]);
+      } else if (typeof v === "object") {
+        if (Array.isArray(v)) throw new Error(`Invalid type`);
+
+        const exps: Expression[] = [];
+        for (const [kk, vv] of Object.entries(v)) {
+          if (kk === "$eq") {
+            exps.push(["=", ["PARAM", k], vv]);
+          } else if (kk === "$ne") {
+            exps.push([
+              "OR",
+              ["<>", ["PARAM", k], vv],
+              ["IS NULL", ["PARAM", k]],
+            ]);
+          } else if (kk === "$lt") {
+            exps.push(["<", ["PARAM", k], vv]);
+          } else if (kk === "$lte") {
+            exps.push(["<=", ["PARAM", k], vv]);
+          } else if (kk === "$gt") {
+            exps.push([">", ["PARAM", k], vv]);
+          } else if (kk === "$gte") {
+            exps.push([">=", ["PARAM", k], vv]);
+          } else {
+            throw new Error(`Operator ${kk} not supported`);
+          }
+          if (!["string", "number", "boolean"].includes(typeof vv))
+            throw new Error(`Invalid value for ${kk} operator`);
+        }
+        if (exps.length === 1) {
+          expressions.push(exps[0]);
+        } else if (exps.length > 1) {
+          const and: Expression = ["AND"];
+          expressions.push(and.concat(exps));
+        }
+      } else {
+        expressions.push(["=", ["PARAM", k], v]);
+      }
+    }
+    if (expressions.length === 1) return expressions[0];
+    if (expressions.length === 0) return true;
+    return ["AND", ...expressions];
+  }
+
+  // empty filter
+  if (!Object.keys(q).length) return true;
+
+  return recursive(q);
+}