// Lists

'use strict';

var isSpace = require('../common/utils').isSpace;


// Search `[-+*][\n ]`, returns next pos after marker on success
// or -1 on fail.
function skipBulletListMarker(state, startLine) {
  var marker, pos, max, ch;

  pos = state.bMarks[startLine] + state.tShift[startLine];
  max = state.eMarks[startLine];

  marker = state.src.charCodeAt(pos++);
  // Check bullet
  if (marker !== 0x2A/* * */ &&
      marker !== 0x2D/* - */ &&
      marker !== 0x2B/* + */) {
    return -1;
  }

  if (pos < max) {
    ch = state.src.charCodeAt(pos);

    if (!isSpace(ch)) {
      // " -test " - is not a list item
      return -1;
    }
  }

  return pos;
}

// Search `\d+[.)][\n ]`, returns next pos after marker on success
// or -1 on fail.
function skipOrderedListMarker(state, startLine) {
  var ch,
      start = state.bMarks[startLine] + state.tShift[startLine],
      pos = start,
      max = state.eMarks[startLine];

  // List marker should have at least 2 chars (digit + dot)
  if (pos + 1 >= max) { return -1; }

  ch = state.src.charCodeAt(pos++);

  if (ch < 0x30/* 0 */ || ch > 0x39/* 9 */) { return -1; }

  for (;;) {
    // EOL -> fail
    if (pos >= max) { return -1; }

    ch = state.src.charCodeAt(pos++);

    if (ch >= 0x30/* 0 */ && ch <= 0x39/* 9 */) {

      // List marker should have no more than 9 digits
      // (prevents integer overflow in browsers)
      if (pos - start >= 10) { return -1; }

      continue;
    }

    // found valid marker
    if (ch === 0x29/* ) */ || ch === 0x2e/* . */) {
      break;
    }

    return -1;
  }


  if (pos < max) {
    ch = state.src.charCodeAt(pos);

    if (!isSpace(ch)) {
      // " 1.test " - is not a list item
      return -1;
    }
  }
  return pos;
}

function markTightParagraphs(state, idx) {
  var i, l,
      level = state.level + 2;

  for (i = idx + 2, l = state.tokens.length - 2; i < l; i++) {
    if (state.tokens[i].level === level && state.tokens[i].type === 'paragraph_open') {
      state.tokens[i + 2].hidden = true;
      state.tokens[i].hidden = true;
      i += 2;
    }
  }
}


module.exports = function list(state, startLine, endLine, silent) {
  var ch,
      contentStart,
      i,
      indent,
      indentAfterMarker,
      initial,
      isOrdered,
      itemLines,
      l,
      listLines,
      listTokIdx,
      markerCharCode,
      markerValue,
      max,
      nextLine,
      offset,
      oldListIndent,
      oldParentType,
      oldSCount,
      oldTShift,
      oldTight,
      pos,
      posAfterMarker,
      prevEmptyEnd,
      start,
      terminate,
      terminatorRules,
      token,
      isTerminatingParagraph = false,
      tight = true;

  // if it's indented more than 3 spaces, it should be a code block
  if (state.sCount[startLine] - state.blkIndent >= 4) { return false; }

  // Special case:
  //  - item 1
  //   - item 2
  //    - item 3
  //     - item 4
  //      - this one is a paragraph continuation
  if (state.listIndent >= 0 &&
      state.sCount[startLine] - state.listIndent >= 4 &&
      state.sCount[startLine] < state.blkIndent) {
    return false;
  }

  // limit conditions when list can interrupt
  // a paragraph (validation mode only)
  if (silent && state.parentType === 'paragraph') {
    // Next list item should still terminate previous list item;
    //
    // This code can fail if plugins use blkIndent as well as lists,
    // but I hope the spec gets fixed long before that happens.
    //
    if (state.tShift[startLine] >= state.blkIndent) {
      isTerminatingParagraph = true;
    }
  }

  // Detect list type and position after marker
  if ((posAfterMarker = skipOrderedListMarker(state, startLine)) >= 0) {
    isOrdered = true;
    start = state.bMarks[startLine] + state.tShift[startLine];
    markerValue = Number(state.src.substr(start, posAfterMarker - start - 1));

    // If we're starting a new ordered list right after
    // a paragraph, it should start with 1.
    if (isTerminatingParagraph && markerValue !== 1) return false;

  } else if ((posAfterMarker = skipBulletListMarker(state, startLine)) >= 0) {
    isOrdered = false;

  } else {
    return false;
  }

  // If we're starting a new unordered list right after
  // a paragraph, first line should not be empty.
  if (isTerminatingParagraph) {
    if (state.skipSpaces(posAfterMarker) >= state.eMarks[startLine]) return false;
  }

  // We should terminate list on style change. Remember first one to compare.
  markerCharCode = state.src.charCodeAt(posAfterMarker - 1);

  // For validation mode we can terminate immediately
  if (silent) { return true; }

  // Start list
  listTokIdx = state.tokens.length;

  if (isOrdered) {
    token       = state.push('ordered_list_open', 'ol', 1);
    if (markerValue !== 1) {
      token.attrs = [ [ 'start', markerValue ] ];
    }

  } else {
    token       = state.push('bullet_list_open', 'ul', 1);
  }

  token.map    = listLines = [ startLine, 0 ];
  token.markup = String.fromCharCode(markerCharCode);

  //
  // Iterate list items
  //

  nextLine = startLine;
  prevEmptyEnd = false;
  terminatorRules = state.md.block.ruler.getRules('list');

  oldParentType = state.parentType;
  state.parentType = 'list';

  while (nextLine < endLine) {
    pos = posAfterMarker;
    max = state.eMarks[nextLine];

    initial = offset = state.sCount[nextLine] + posAfterMarker - (state.bMarks[startLine] + state.tShift[startLine]);

    while (pos < max) {
      ch = state.src.charCodeAt(pos);

      if (ch === 0x09) {
        offset += 4 - (offset + state.bsCount[nextLine]) % 4;
      } else if (ch === 0x20) {
        offset++;
      } else {
        break;
      }

      pos++;
    }

    contentStart = pos;

    if (contentStart >= max) {
      // trimming space in "-    \n  3" case, indent is 1 here
      indentAfterMarker = 1;
    } else {
      indentAfterMarker = offset - initial;
    }

    // If we have more than 4 spaces, the indent is 1
    // (the rest is just indented code block)
    if (indentAfterMarker > 4) { indentAfterMarker = 1; }

    // "  -  test"
    //  ^^^^^ - calculating total length of this thing
    indent = initial + indentAfterMarker;

    // Run subparser & write tokens
    token        = state.push('list_item_open', 'li', 1);
    token.markup = String.fromCharCode(markerCharCode);
    token.map    = itemLines = [ startLine, 0 ];

    // change current state, then restore it after parser subcall
    oldTight = state.tight;
    oldTShift = state.tShift[startLine];
    oldSCount = state.sCount[startLine];

    //  - example list
    // ^ listIndent position will be here
    //   ^ blkIndent position will be here
    //
    oldListIndent = state.listIndent;
    state.listIndent = state.blkIndent;
    state.blkIndent = indent;

    state.tight = true;
    state.tShift[startLine] = contentStart - state.bMarks[startLine];
    state.sCount[startLine] = offset;

    if (contentStart >= max && state.isEmpty(startLine + 1)) {
      // workaround for this case
      // (list item is empty, list terminates before "foo"):
      // ~~~~~~~~
      //   -
      //
      //     foo
      // ~~~~~~~~
      state.line = Math.min(state.line + 2, endLine);
    } else {
      state.md.block.tokenize(state, startLine, endLine, true);
    }

    // If any of list item is tight, mark list as tight
    if (!state.tight || prevEmptyEnd) {
      tight = false;
    }
    // Item become loose if finish with empty line,
    // but we should filter last element, because it means list finish
    prevEmptyEnd = (state.line - startLine) > 1 && state.isEmpty(state.line - 1);

    state.blkIndent = state.listIndent;
    state.listIndent = oldListIndent;
    state.tShift[startLine] = oldTShift;
    state.sCount[startLine] = oldSCount;
    state.tight = oldTight;

    token        = state.push('list_item_close', 'li', -1);
    token.markup = String.fromCharCode(markerCharCode);

    nextLine = startLine = state.line;
    itemLines[1] = nextLine;
    contentStart = state.bMarks[startLine];

    if (nextLine >= endLine) { break; }

    //
    // Try to check if list is terminated or continued.
    //
    if (state.sCount[nextLine] < state.blkIndent) { break; }

    // if it's indented more than 3 spaces, it should be a code block
    if (state.sCount[startLine] - state.blkIndent >= 4) { break; }

    // fail if terminating block found
    terminate = false;
    for (i = 0, l = terminatorRules.length; i < l; i++) {
      if (terminatorRules[i](state, nextLine, endLine, true)) {
        terminate = true;
        break;
      }
    }
    if (terminate) { break; }

    // fail if list has another type
    if (isOrdered) {
      posAfterMarker = skipOrderedListMarker(state, nextLine);
      if (posAfterMarker < 0) { break; }
    } else {
      posAfterMarker = skipBulletListMarker(state, nextLine);
      if (posAfterMarker < 0) { break; }
    }

    if (markerCharCode !== state.src.charCodeAt(posAfterMarker - 1)) { break; }
  }

  // Finalize list
  if (isOrdered) {
    token = state.push('ordered_list_close', 'ol', -1);
  } else {
    token = state.push('bullet_list_close', 'ul', -1);
  }
  token.markup = String.fromCharCode(markerCharCode);

  listLines[1] = nextLine;
  state.line = nextLine;

  state.parentType = oldParentType;

  // mark paragraphs tight if needed
  if (tight) {
    markTightParagraphs(state, listTokIdx);
  }

  return true;
};