'use strict';

const Char = {
  ANCHOR: '&',
  COMMENT: '#',
  TAG: '!',
  DIRECTIVES_END: '-',
  DOCUMENT_END: '.'
};
const Type = {
  ALIAS: 'ALIAS',
  BLANK_LINE: 'BLANK_LINE',
  BLOCK_FOLDED: 'BLOCK_FOLDED',
  BLOCK_LITERAL: 'BLOCK_LITERAL',
  COMMENT: 'COMMENT',
  DIRECTIVE: 'DIRECTIVE',
  DOCUMENT: 'DOCUMENT',
  FLOW_MAP: 'FLOW_MAP',
  FLOW_SEQ: 'FLOW_SEQ',
  MAP: 'MAP',
  MAP_KEY: 'MAP_KEY',
  MAP_VALUE: 'MAP_VALUE',
  PLAIN: 'PLAIN',
  QUOTE_DOUBLE: 'QUOTE_DOUBLE',
  QUOTE_SINGLE: 'QUOTE_SINGLE',
  SEQ: 'SEQ',
  SEQ_ITEM: 'SEQ_ITEM'
};
const defaultTagPrefix = 'tag:yaml.org,2002:';
const defaultTags = {
  MAP: 'tag:yaml.org,2002:map',
  SEQ: 'tag:yaml.org,2002:seq',
  STR: 'tag:yaml.org,2002:str'
};

function findLineStarts(src) {
  const ls = [0];
  let offset = src.indexOf('\n');

  while (offset !== -1) {
    offset += 1;
    ls.push(offset);
    offset = src.indexOf('\n', offset);
  }

  return ls;
}

function getSrcInfo(cst) {
  let lineStarts, src;

  if (typeof cst === 'string') {
    lineStarts = findLineStarts(cst);
    src = cst;
  } else {
    if (Array.isArray(cst)) cst = cst[0];

    if (cst && cst.context) {
      if (!cst.lineStarts) cst.lineStarts = findLineStarts(cst.context.src);
      lineStarts = cst.lineStarts;
      src = cst.context.src;
    }
  }

  return {
    lineStarts,
    src
  };
}
/**
 * @typedef {Object} LinePos - One-indexed position in the source
 * @property {number} line
 * @property {number} col
 */

/**
 * Determine the line/col position matching a character offset.
 *
 * Accepts a source string or a CST document as the second parameter. With
 * the latter, starting indices for lines are cached in the document as
 * `lineStarts: number[]`.
 *
 * Returns a one-indexed `{ line, col }` location if found, or
 * `undefined` otherwise.
 *
 * @param {number} offset
 * @param {string|Document|Document[]} cst
 * @returns {?LinePos}
 */


function getLinePos(offset, cst) {
  if (typeof offset !== 'number' || offset < 0) return null;
  const {
    lineStarts,
    src
  } = getSrcInfo(cst);
  if (!lineStarts || !src || offset > src.length) return null;

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

    if (offset < start) {
      return {
        line: i,
        col: offset - lineStarts[i - 1] + 1
      };
    }

    if (offset === start) return {
      line: i + 1,
      col: 1
    };
  }

  const line = lineStarts.length;
  return {
    line,
    col: offset - lineStarts[line - 1] + 1
  };
}
/**
 * Get a specified line from the source.
 *
 * Accepts a source string or a CST document as the second parameter. With
 * the latter, starting indices for lines are cached in the document as
 * `lineStarts: number[]`.
 *
 * Returns the line as a string if found, or `null` otherwise.
 *
 * @param {number} line One-indexed line number
 * @param {string|Document|Document[]} cst
 * @returns {?string}
 */

function getLine(line, cst) {
  const {
    lineStarts,
    src
  } = getSrcInfo(cst);
  if (!lineStarts || !(line >= 1) || line > lineStarts.length) return null;
  const start = lineStarts[line - 1];
  let end = lineStarts[line]; // undefined for last line; that's ok for slice()

  while (end && end > start && src[end - 1] === '\n') --end;

  return src.slice(start, end);
}
/**
 * Pretty-print the starting line from the source indicated by the range `pos`
 *
 * Trims output to `maxWidth` chars while keeping the starting column visible,
 * using `…` at either end to indicate dropped characters.
 *
 * Returns a two-line string (or `null`) with `\n` as separator; the second line
 * will hold appropriately indented `^` marks indicating the column range.
 *
 * @param {Object} pos
 * @param {LinePos} pos.start
 * @param {LinePos} [pos.end]
 * @param {string|Document|Document[]*} cst
 * @param {number} [maxWidth=80]
 * @returns {?string}
 */

function getPrettyContext({
  start,
  end
}, cst, maxWidth = 80) {
  let src = getLine(start.line, cst);
  if (!src) return null;
  let {
    col
  } = start;

  if (src.length > maxWidth) {
    if (col <= maxWidth - 10) {
      src = src.substr(0, maxWidth - 1) + '…';
    } else {
      const halfWidth = Math.round(maxWidth / 2);
      if (src.length > col + halfWidth) src = src.substr(0, col + halfWidth - 1) + '…';
      col -= src.length - maxWidth;
      src = '…' + src.substr(1 - maxWidth);
    }
  }

  let errLen = 1;
  let errEnd = '';

  if (end) {
    if (end.line === start.line && col + (end.col - start.col) <= maxWidth + 1) {
      errLen = end.col - start.col;
    } else {
      errLen = Math.min(src.length + 1, maxWidth) - col;
      errEnd = '…';
    }
  }

  const offset = col > 1 ? ' '.repeat(col - 1) : '';
  const err = '^'.repeat(errLen);
  return `${src}\n${offset}${err}${errEnd}`;
}

class Range {
  static copy(orig) {
    return new Range(orig.start, orig.end);
  }

  constructor(start, end) {
    this.start = start;
    this.end = end || start;
  }

  isEmpty() {
    return typeof this.start !== 'number' || !this.end || this.end <= this.start;
  }
  /**
   * Set `origStart` and `origEnd` to point to the original source range for
   * this node, which may differ due to dropped CR characters.
   *
   * @param {number[]} cr - Positions of dropped CR characters
   * @param {number} offset - Starting index of `cr` from the last call
   * @returns {number} - The next offset, matching the one found for `origStart`
   */


  setOrigRange(cr, offset) {
    const {
      start,
      end
    } = this;

    if (cr.length === 0 || end <= cr[0]) {
      this.origStart = start;
      this.origEnd = end;
      return offset;
    }

    let i = offset;

    while (i < cr.length) {
      if (cr[i] > start) break;else ++i;
    }

    this.origStart = start + i;
    const nextOffset = i;

    while (i < cr.length) {
      // if end was at \n, it should now be at \r
      if (cr[i] >= end) break;else ++i;
    }

    this.origEnd = end + i;
    return nextOffset;
  }

}

/** Root class of all nodes */

class Node {
  static addStringTerminator(src, offset, str) {
    if (str[str.length - 1] === '\n') return str;
    const next = Node.endOfWhiteSpace(src, offset);
    return next >= src.length || src[next] === '\n' ? str + '\n' : str;
  } // ^(---|...)


  static atDocumentBoundary(src, offset, sep) {
    const ch0 = src[offset];
    if (!ch0) return true;
    const prev = src[offset - 1];
    if (prev && prev !== '\n') return false;

    if (sep) {
      if (ch0 !== sep) return false;
    } else {
      if (ch0 !== Char.DIRECTIVES_END && ch0 !== Char.DOCUMENT_END) return false;
    }

    const ch1 = src[offset + 1];
    const ch2 = src[offset + 2];
    if (ch1 !== ch0 || ch2 !== ch0) return false;
    const ch3 = src[offset + 3];
    return !ch3 || ch3 === '\n' || ch3 === '\t' || ch3 === ' ';
  }

  static endOfIdentifier(src, offset) {
    let ch = src[offset];
    const isVerbatim = ch === '<';
    const notOk = isVerbatim ? ['\n', '\t', ' ', '>'] : ['\n', '\t', ' ', '[', ']', '{', '}', ','];

    while (ch && notOk.indexOf(ch) === -1) ch = src[offset += 1];

    if (isVerbatim && ch === '>') offset += 1;
    return offset;
  }

  static endOfIndent(src, offset) {
    let ch = src[offset];

    while (ch === ' ') ch = src[offset += 1];

    return offset;
  }

  static endOfLine(src, offset) {
    let ch = src[offset];

    while (ch && ch !== '\n') ch = src[offset += 1];

    return offset;
  }

  static endOfWhiteSpace(src, offset) {
    let ch = src[offset];

    while (ch === '\t' || ch === ' ') ch = src[offset += 1];

    return offset;
  }

  static startOfLine(src, offset) {
    let ch = src[offset - 1];
    if (ch === '\n') return offset;

    while (ch && ch !== '\n') ch = src[offset -= 1];

    return offset + 1;
  }
  /**
   * End of indentation, or null if the line's indent level is not more
   * than `indent`
   *
   * @param {string} src
   * @param {number} indent
   * @param {number} lineStart
   * @returns {?number}
   */


  static endOfBlockIndent(src, indent, lineStart) {
    const inEnd = Node.endOfIndent(src, lineStart);

    if (inEnd > lineStart + indent) {
      return inEnd;
    } else {
      const wsEnd = Node.endOfWhiteSpace(src, inEnd);
      const ch = src[wsEnd];
      if (!ch || ch === '\n') return wsEnd;
    }

    return null;
  }

  static atBlank(src, offset, endAsBlank) {
    const ch = src[offset];
    return ch === '\n' || ch === '\t' || ch === ' ' || endAsBlank && !ch;
  }

  static nextNodeIsIndented(ch, indentDiff, indicatorAsIndent) {
    if (!ch || indentDiff < 0) return false;
    if (indentDiff > 0) return true;
    return indicatorAsIndent && ch === '-';
  } // should be at line or string end, or at next non-whitespace char


  static normalizeOffset(src, offset) {
    const ch = src[offset];
    return !ch ? offset : ch !== '\n' && src[offset - 1] === '\n' ? offset - 1 : Node.endOfWhiteSpace(src, offset);
  } // fold single newline into space, multiple newlines to N - 1 newlines
  // presumes src[offset] === '\n'


  static foldNewline(src, offset, indent) {
    let inCount = 0;
    let error = false;
    let fold = '';
    let ch = src[offset + 1];

    while (ch === ' ' || ch === '\t' || ch === '\n') {
      switch (ch) {
        case '\n':
          inCount = 0;
          offset += 1;
          fold += '\n';
          break;

        case '\t':
          if (inCount <= indent) error = true;
          offset = Node.endOfWhiteSpace(src, offset + 2) - 1;
          break;

        case ' ':
          inCount += 1;
          offset += 1;
          break;
      }

      ch = src[offset + 1];
    }

    if (!fold) fold = ' ';
    if (ch && inCount <= indent) error = true;
    return {
      fold,
      offset,
      error
    };
  }

  constructor(type, props, context) {
    Object.defineProperty(this, 'context', {
      value: context || null,
      writable: true
    });
    this.error = null;
    this.range = null;
    this.valueRange = null;
    this.props = props || [];
    this.type = type;
    this.value = null;
  }

  getPropValue(idx, key, skipKey) {
    if (!this.context) return null;
    const {
      src
    } = this.context;
    const prop = this.props[idx];
    return prop && src[prop.start] === key ? src.slice(prop.start + (skipKey ? 1 : 0), prop.end) : null;
  }

  get anchor() {
    for (let i = 0; i < this.props.length; ++i) {
      const anchor = this.getPropValue(i, Char.ANCHOR, true);
      if (anchor != null) return anchor;
    }

    return null;
  }

  get comment() {
    const comments = [];

    for (let i = 0; i < this.props.length; ++i) {
      const comment = this.getPropValue(i, Char.COMMENT, true);
      if (comment != null) comments.push(comment);
    }

    return comments.length > 0 ? comments.join('\n') : null;
  }

  commentHasRequiredWhitespace(start) {
    const {
      src
    } = this.context;
    if (this.header && start === this.header.end) return false;
    if (!this.valueRange) return false;
    const {
      end
    } = this.valueRange;
    return start !== end || Node.atBlank(src, end - 1);
  }

  get hasComment() {
    if (this.context) {
      const {
        src
      } = this.context;

      for (let i = 0; i < this.props.length; ++i) {
        if (src[this.props[i].start] === Char.COMMENT) return true;
      }
    }

    return false;
  }

  get hasProps() {
    if (this.context) {
      const {
        src
      } = this.context;

      for (let i = 0; i < this.props.length; ++i) {
        if (src[this.props[i].start] !== Char.COMMENT) return true;
      }
    }

    return false;
  }

  get includesTrailingLines() {
    return false;
  }

  get jsonLike() {
    const jsonLikeTypes = [Type.FLOW_MAP, Type.FLOW_SEQ, Type.QUOTE_DOUBLE, Type.QUOTE_SINGLE];
    return jsonLikeTypes.indexOf(this.type) !== -1;
  }

  get rangeAsLinePos() {
    if (!this.range || !this.context) return undefined;
    const start = getLinePos(this.range.start, this.context.root);
    if (!start) return undefined;
    const end = getLinePos(this.range.end, this.context.root);
    return {
      start,
      end
    };
  }

  get rawValue() {
    if (!this.valueRange || !this.context) return null;
    const {
      start,
      end
    } = this.valueRange;
    return this.context.src.slice(start, end);
  }

  get tag() {
    for (let i = 0; i < this.props.length; ++i) {
      const tag = this.getPropValue(i, Char.TAG, false);

      if (tag != null) {
        if (tag[1] === '<') {
          return {
            verbatim: tag.slice(2, -1)
          };
        } else {
          // eslint-disable-next-line no-unused-vars
          const [_, handle, suffix] = tag.match(/^(.*!)([^!]*)$/);
          return {
            handle,
            suffix
          };
        }
      }
    }

    return null;
  }

  get valueRangeContainsNewline() {
    if (!this.valueRange || !this.context) return false;
    const {
      start,
      end
    } = this.valueRange;
    const {
      src
    } = this.context;

    for (let i = start; i < end; ++i) {
      if (src[i] === '\n') return true;
    }

    return false;
  }

  parseComment(start) {
    const {
      src
    } = this.context;

    if (src[start] === Char.COMMENT) {
      const end = Node.endOfLine(src, start + 1);
      const commentRange = new Range(start, end);
      this.props.push(commentRange);
      return end;
    }

    return start;
  }
  /**
   * Populates the `origStart` and `origEnd` values of all ranges for this
   * node. Extended by child classes to handle descendant nodes.
   *
   * @param {number[]} cr - Positions of dropped CR characters
   * @param {number} offset - Starting index of `cr` from the last call
   * @returns {number} - The next offset, matching the one found for `origStart`
   */


  setOrigRanges(cr, offset) {
    if (this.range) offset = this.range.setOrigRange(cr, offset);
    if (this.valueRange) this.valueRange.setOrigRange(cr, offset);
    this.props.forEach(prop => prop.setOrigRange(cr, offset));
    return offset;
  }

  toString() {
    const {
      context: {
        src
      },
      range,
      value
    } = this;
    if (value != null) return value;
    const str = src.slice(range.start, range.end);
    return Node.addStringTerminator(src, range.end, str);
  }

}

class YAMLError extends Error {
  constructor(name, source, message) {
    if (!message || !(source instanceof Node)) throw new Error(`Invalid arguments for new ${name}`);
    super();
    this.name = name;
    this.message = message;
    this.source = source;
  }

  makePretty() {
    if (!this.source) return;
    this.nodeType = this.source.type;
    const cst = this.source.context && this.source.context.root;

    if (typeof this.offset === 'number') {
      this.range = new Range(this.offset, this.offset + 1);
      const start = cst && getLinePos(this.offset, cst);

      if (start) {
        const end = {
          line: start.line,
          col: start.col + 1
        };
        this.linePos = {
          start,
          end
        };
      }

      delete this.offset;
    } else {
      this.range = this.source.range;
      this.linePos = this.source.rangeAsLinePos;
    }

    if (this.linePos) {
      const {
        line,
        col
      } = this.linePos.start;
      this.message += ` at line ${line}, column ${col}`;
      const ctx = cst && getPrettyContext(this.linePos, cst);
      if (ctx) this.message += `:\n\n${ctx}\n`;
    }

    delete this.source;
  }

}
class YAMLReferenceError extends YAMLError {
  constructor(source, message) {
    super('YAMLReferenceError', source, message);
  }

}
class YAMLSemanticError extends YAMLError {
  constructor(source, message) {
    super('YAMLSemanticError', source, message);
  }

}
class YAMLSyntaxError extends YAMLError {
  constructor(source, message) {
    super('YAMLSyntaxError', source, message);
  }

}
class YAMLWarning extends YAMLError {
  constructor(source, message) {
    super('YAMLWarning', source, message);
  }

}

function _defineProperty(obj, key, value) {
  if (key in obj) {
    Object.defineProperty(obj, key, {
      value: value,
      enumerable: true,
      configurable: true,
      writable: true
    });
  } else {
    obj[key] = value;
  }

  return obj;
}

class PlainValue extends Node {
  static endOfLine(src, start, inFlow) {
    let ch = src[start];
    let offset = start;

    while (ch && ch !== '\n') {
      if (inFlow && (ch === '[' || ch === ']' || ch === '{' || ch === '}' || ch === ',')) break;
      const next = src[offset + 1];
      if (ch === ':' && (!next || next === '\n' || next === '\t' || next === ' ' || inFlow && next === ',')) break;
      if ((ch === ' ' || ch === '\t') && next === '#') break;
      offset += 1;
      ch = next;
    }

    return offset;
  }

  get strValue() {
    if (!this.valueRange || !this.context) return null;
    let {
      start,
      end
    } = this.valueRange;
    const {
      src
    } = this.context;
    let ch = src[end - 1];

    while (start < end && (ch === '\n' || ch === '\t' || ch === ' ')) ch = src[--end - 1];

    let str = '';

    for (let i = start; i < end; ++i) {
      const ch = src[i];

      if (ch === '\n') {
        const {
          fold,
          offset
        } = Node.foldNewline(src, i, -1);
        str += fold;
        i = offset;
      } else if (ch === ' ' || ch === '\t') {
        // trim trailing whitespace
        const wsStart = i;
        let next = src[i + 1];

        while (i < end && (next === ' ' || next === '\t')) {
          i += 1;
          next = src[i + 1];
        }

        if (next !== '\n') str += i > wsStart ? src.slice(wsStart, i + 1) : ch;
      } else {
        str += ch;
      }
    }

    const ch0 = src[start];

    switch (ch0) {
      case '\t':
        {
          const msg = 'Plain value cannot start with a tab character';
          const errors = [new YAMLSemanticError(this, msg)];
          return {
            errors,
            str
          };
        }

      case '@':
      case '`':
        {
          const msg = `Plain value cannot start with reserved character ${ch0}`;
          const errors = [new YAMLSemanticError(this, msg)];
          return {
            errors,
            str
          };
        }

      default:
        return str;
    }
  }

  parseBlockValue(start) {
    const {
      indent,
      inFlow,
      src
    } = this.context;
    let offset = start;
    let valueEnd = start;

    for (let ch = src[offset]; ch === '\n'; ch = src[offset]) {
      if (Node.atDocumentBoundary(src, offset + 1)) break;
      const end = Node.endOfBlockIndent(src, indent, offset + 1);
      if (end === null || src[end] === '#') break;

      if (src[end] === '\n') {
        offset = end;
      } else {
        valueEnd = PlainValue.endOfLine(src, end, inFlow);
        offset = valueEnd;
      }
    }

    if (this.valueRange.isEmpty()) this.valueRange.start = start;
    this.valueRange.end = valueEnd;
    return valueEnd;
  }
  /**
   * Parses a plain value from the source
   *
   * Accepted forms are:
   * ```
   * #comment
   *
   * first line
   *
   * first line #comment
   *
   * first line
   * block
   * lines
   *
   * #comment
   * block
   * lines
   * ```
   * where block lines are empty or have an indent level greater than `indent`.
   *
   * @param {ParseContext} context
   * @param {number} start - Index of first character
   * @returns {number} - Index of the character after this scalar, may be `\n`
   */


  parse(context, start) {
    this.context = context;
    const {
      inFlow,
      src
    } = context;
    let offset = start;
    const ch = src[offset];

    if (ch && ch !== '#' && ch !== '\n') {
      offset = PlainValue.endOfLine(src, start, inFlow);
    }

    this.valueRange = new Range(start, offset);
    offset = Node.endOfWhiteSpace(src, offset);
    offset = this.parseComment(offset);

    if (!this.hasComment || this.valueRange.isEmpty()) {
      offset = this.parseBlockValue(offset);
    }

    return offset;
  }

}

exports.Char = Char;
exports.Node = Node;
exports.PlainValue = PlainValue;
exports.Range = Range;
exports.Type = Type;
exports.YAMLError = YAMLError;
exports.YAMLReferenceError = YAMLReferenceError;
exports.YAMLSemanticError = YAMLSemanticError;
exports.YAMLSyntaxError = YAMLSyntaxError;
exports.YAMLWarning = YAMLWarning;
exports._defineProperty = _defineProperty;
exports.defaultTagPrefix = defaultTagPrefix;
exports.defaultTags = defaultTags;