Add index.js

index.js

@@ -0,0 +1,188 @@
+/**
+ * Adds a prefix to a string.
+ * @param {string} str - The original string.
+ * @param {string} prefix - The prefix to add.
+ * @returns {string} The string with the prefix added.
+ */
+function addPrefix(str, prefix) {
+  return prefix + str;
+}
+
+/**
+ * Removes a prefix from a string.
+ * @param {string} str - The original string.
+ * @param {string} prefix - The prefix to remove.
+ * @returns {string} The string with the prefix removed.
+ */
+function removePrefix(str, prefix) {
+  if (str.startsWith(prefix)) {
+    return str.slice(prefix.length);
+  }
+  return str;
+}
+
+/**
+ * Adds a suffix to a string.
+ * @param {string} str - The original string.
+ * @param {string} suffix - The suffix to add.
+ * @returns {string} The string with the suffix added.
+ */
+function addSuffix(str, suffix) {
+  return str + suffix;
+}
+
+/**
+ * Removes a suffix from a string.
+ * @param {string} str - The original string.
+ * @param {string} suffix - The suffix to remove.
+ * @returns {string} The string with the suffix removed.
+ */
+function removeSuffix(str, suffix) {
+  if (str.endsWith(suffix)) {
+    return str.slice(0, -suffix.length);
+  }
+  return str;
+}
+
+/**
+ * Tokenizes a string into tokens
+ * @param {string} str 
+ * @returns {Array<string>} tokens
+ */
+function tokenize(str) {
+  const tokens = [];
+  let currentToken = "";
+  let inQuotes = false;
+  let escapeNext = false;
+
+  for (let i = 0; i < str.length; i++) {
+    const char = str[i];
+
+    if (escapeNext) {
+      currentToken += char;
+      escapeNext = false;
+    } else if (char === "\\") {
+      escapeNext = true;
+    } else if (char === '"') {
+      inQuotes = !inQuotes;
+    } else if ((char === " " || char === "\n" || char === "\r") && !inQuotes) {
+      if (currentToken !== "") {
+        tokens.push(currentToken);
+        currentToken = "";
+      }
+    } else {
+      currentToken += char;
+    }
+  }
+
+  if (currentToken !== "") {
+    tokens.push(currentToken);
+  }
+
+  return tokens;
+}
+
+/**
+ * Manipulates the filename based on rules
+ * @param {string} string
+ * @param {string} filename
+ * @returns
+ */
+function manipulateFilename(string, filename) {
+  /**
+   * @type {{dimension: string, action: string, target:string, value: string}}  cmd
+   */
+  let cmd;
+
+  /**
+   * @type {Array<{dimension: string, action: string, target:string, value: string}>} commands
+   */
+  let commands = [];
+  let state = "next";
+
+  for (const token of tokenize(string)) {
+    switch (state) {
+      case "next":
+        if (token === "for") {
+          cmd = {};
+          state = "dimension";
+        } else {
+          throw new Error("Syntax Error, command must start with 'for'");
+        }
+        break;
+      case "dimension":
+        if (token === "2D" || token === "3D") {
+          cmd = { ...cmd, dimension: token };
+          state = "action";
+        } else {
+          throw new Error("Syntax Error, command must be '2D' or '3D'");
+        }
+        break;
+      case "action":
+        if (token === "add" || token === "remove") {
+          cmd = { ...cmd, action: token };
+          state = "target";
+        } else {
+          throw new Error("Syntax Error, command must be 'add' or 'remove'");
+        }
+        break;
+      case "target":
+        if (token === "all" && cmd.action === "add") { 
+          throw new Error(
+            "Syntax Error, you cannot use an 'all' target with an 'add' action, only 'remove' is allowed"
+          );
+        } else if (token === "all" && cmd.action === "remove") {
+          cmd = { ...cmd, target: token };
+          state = "value";        
+        } else if (token === "prefix" || token === "suffix") {
+          cmd = { ...cmd, target: token };
+          state = "value";
+        } else {
+          throw new Error(
+            "Syntax Error, command must be 'prefix', 'suffix', or 'all'"
+          );
+        }
+        break;
+      case "value":
+        cmd = { ...cmd, value: token };
+        commands.push(cmd);
+        state = "more";
+      case "more":
+        if (token === "and") {
+          state = "next";
+        }
+        break;
+      default:
+        break;
+    }
+  }
+
+  for (const command of commands) {
+    if (command.target === "prefix" && command.action === "add") {
+      filename = addPrefix(filename, command.value);
+    }
+    if (command.target === "prefix" && command.action === "remove") {
+      filename = removePrefix(filename, command.value);
+    }
+    if (command.target === "suffix" && command.action === "add") {
+      filename = addSuffix(filename, command.value);
+    }
+    if (command.target === "suffix" && command.action === "remove") {
+      filename = removeSuffix(filename, command.value);
+    }
+    if (command.target === "all" && command.action === "remove") {
+      filename = filename.replace(command.value, "");      
+    }
+  }
+
+  return filename;
+}
+
+const cmdStr = `for 2D add prefix "hello-" and 
+                for 2D add suffix "-3" and 
+                for 2D add suffix "-3" and 
+                for 2D add suffix "-4" and 
+                for 2D add suffix "-5" and for 2D remove all "-3"`;
+const filename = "example";
+const result = manipulateFilename(cmdStr, filename);
+console.log(result); // Output: "hello-example-3"