import { toUTF8String } from "./utils.js";
const PNMTypes = {
  P1: "pbm/ascii",
  P2: "pgm/ascii",
  P3: "ppm/ascii",
  P4: "pbm",
  P5: "pgm",
  P6: "ppm",
  P7: "pam",
  PF: "pfm"
};
const handlers = {
  default: (lines) => {
    let dimensions = [];
    while (lines.length > 0) {
      const line = lines.shift();
      if (line[0] === "#") {
        continue;
      }
      dimensions = line.split(" ");
      break;
    }
    if (dimensions.length === 2) {
      return {
        height: parseInt(dimensions[1], 10),
        width: parseInt(dimensions[0], 10)
      };
    } else {
      throw new TypeError("Invalid PNM");
    }
  },
  pam: (lines) => {
    const size = {};
    while (lines.length > 0) {
      const line = lines.shift();
      if (line.length > 16 || line.charCodeAt(0) > 128) {
        continue;
      }
      const [key, value] = line.split(" ");
      if (key && value) {
        size[key.toLowerCase()] = parseInt(value, 10);
      }
      if (size.height && size.width) {
        break;
      }
    }
    if (size.height && size.width) {
      return {
        height: size.height,
        width: size.width
      };
    } else {
      throw new TypeError("Invalid PAM");
    }
  }
};
const PNM = {
  validate: (input) => toUTF8String(input, 0, 2) in PNMTypes,
  calculate(input) {
    const signature = toUTF8String(input, 0, 2);
    const type = PNMTypes[signature];
    const lines = toUTF8String(input, 3).split(/[\r\n]+/);
    const handler = handlers[type] || handlers.default;
    return handler(lines);
  }
};
export {
  PNM
};