react-native-advanced-input-mask/src/web/helper/FormatSanitizer.ts

Text input mask for React Native on iOS, Android and web. Synchronous and easy formatting without hustle

import FormatError from "./FormatError";

export default class FormatSanitizer {
  public static sanitize(formatString: string): string {
    FormatSanitizer.checkOpenBraces(formatString);
    const blocks = this.divideBlocksWithMixedCharacters(
      this.getFormatBlocks(formatString),
    );

    return FormatSanitizer.sortFormatBlocks(blocks).join("");
  }

  private static getFormatBlocks(formatString: string): string[] {
    const blocks: string[] = [];
    let currentBlock = "";
    let escape = false;

    for (const char of formatString) {
      if (char === "\\") {
        if (!escape) {
          escape = true;
          currentBlock += char;
          continue;
        }
      }

      if ((char === "[" || char === "{") && !escape) {
        if (currentBlock.length > 0) {
          blocks.push(currentBlock);
        }
        currentBlock = "";
      }

      currentBlock += char;

      if ((char === "]" || char === "}") && !escape) {
        blocks.push(currentBlock);
        currentBlock = "";
      }

      escape = false;
    }

    if (currentBlock.length > 0) {
      blocks.push(currentBlock);
    }

    return blocks;
  }

  private static divideBlocksWithMixedCharacters(blocks: string[]): string[] {
    const resultingBlocks: string[] = [];

    for (const block of blocks) {
      if (block.startsWith("[")) {
        let blockBuffer = "";

        for (let i = 0; i < block.length; i++) {
          const blockCharacter = block[i];

          if (blockCharacter === "[") {
            blockBuffer += blockCharacter;
            continue;
          }
          if (blockCharacter === "]" && !blockBuffer.endsWith("\\")) {
            blockBuffer += blockCharacter;
            resultingBlocks.push(blockBuffer);
            break;
          }
          if (
            (blockCharacter === "0" || blockCharacter === "9") &&
            (blockBuffer.includes("A") ||
              blockBuffer.includes("a") ||
              blockBuffer.includes("-") ||
              blockBuffer.includes("_"))
          ) {
            blockBuffer += "]";
            resultingBlocks.push(blockBuffer);
            blockBuffer = "[" + blockCharacter;
            continue;
          }
          if (
            (blockCharacter === "A" || blockCharacter === "a") &&
            (blockBuffer.includes("0") ||
              blockBuffer.includes("9") ||
              blockBuffer.includes("-") ||
              blockBuffer.includes("_"))
          ) {
            blockBuffer += "]";
            resultingBlocks.push(blockBuffer);
            blockBuffer = "[" + blockCharacter;
            continue;
          }
          if (
            (blockCharacter === "-" || blockCharacter === "_") &&
            (blockBuffer.includes("0") ||
              blockBuffer.includes("9") ||
              blockBuffer.includes("A") ||
              blockBuffer.includes("a"))
          ) {
            blockBuffer += "]";
            resultingBlocks.push(blockBuffer);
            blockBuffer = "[" + blockCharacter;
            continue;
          }
          blockBuffer += blockCharacter;
        }
      } else {
        resultingBlocks.push(block);
      }
    }

    return resultingBlocks;
  }

  private static sortFormatBlocks(blocks: string[]): string[] {
    const sortedBlocks: string[] = [];

    for (const block of blocks) {
      let sortedBlock: string;

      if (block.startsWith("[")) {
        if (
          block.includes("0") ||
          block.includes("9") ||
          block.includes("A") ||
          block.includes("a")
        ) {
          sortedBlock =
            "[" +
            block.replace("[", "").replace("]", "").split("").sort().join("") +
            "]";
        } else {
          // For `_` or `-`, temporarily replace for sorting
          sortedBlock =
            "[" +
            block
              .replace("[", "")
              .replace("]", "")
              .replace("_", "A")
              .replace("-", "a")
              .split("")
              .sort()
              .join("") +
            "]";
          sortedBlock = sortedBlock.replace("A", "_").replace("a", "-");
        }
      } else {
        sortedBlock = block;
      }
      sortedBlocks.push(sortedBlock);
    }

    return sortedBlocks;
  }

  private static checkOpenBraces(str: string): void {
    let escape = false;
    let squareBraceOpen = false;
    let curlyBraceOpen = false;

    for (const char of str) {
      if (char === "\\") {
        escape = !escape;
        continue;
      }
      if (char === "[") {
        if (squareBraceOpen) {
          throw new FormatError();
        }
        squareBraceOpen = !escape;
      }
      if (char === "]" && !escape) {
        squareBraceOpen = false;
      }
      if (char === "{") {
        if (curlyBraceOpen) {
          throw new FormatError();
        }
        curlyBraceOpen = !escape;
      }
      if (char === "}" && !escape) {
        curlyBraceOpen = false;
      }
      escape = false;
    }
  }
}