// Block quotes

'use strict';

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


module.exports = function blockquote(state, startLine, endLine, silent) {
  var nextLine, lastLineEmpty, oldTShift, oldSCount, oldBMarks, oldIndent, oldParentType, lines, initial, offset, ch,
      terminatorRules, token,
      i, l, terminate,
      pos = state.bMarks[startLine] + state.tShift[startLine],
      max = state.eMarks[startLine];

  // check the block quote marker
  if (state.src.charCodeAt(pos++) !== 0x3E/* > */) { return false; }

  // we know that it's going to be a valid blockquote,
  // so no point trying to find the end of it in silent mode
  if (silent) { return true; }

  // skip one optional space (but not tab, check cmark impl) after '>'
  if (state.src.charCodeAt(pos) === 0x20) { pos++; }

  oldIndent = state.blkIndent;
  state.blkIndent = 0;

  // skip spaces after ">" and re-calculate offset
  initial = offset = state.sCount[startLine] + pos - (state.bMarks[startLine] + state.tShift[startLine]);

  oldBMarks = [ state.bMarks[startLine] ];
  state.bMarks[startLine] = pos;

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

    if (isSpace(ch)) {
      if (ch === 0x09) {
        offset += 4 - offset % 4;
      } else {
        offset++;
      }
    } else {
      break;
    }

    pos++;
  }

  lastLineEmpty = pos >= max;

  oldSCount = [ state.sCount[startLine] ];
  state.sCount[startLine] = offset - initial;

  oldTShift = [ state.tShift[startLine] ];
  state.tShift[startLine] = pos - state.bMarks[startLine];

  terminatorRules = state.md.block.ruler.getRules('blockquote');

  // Search the end of the block
  //
  // Block ends with either:
  //  1. an empty line outside:
  //     ```
  //     > test
  //
  //     ```
  //  2. an empty line inside:
  //     ```
  //     >
  //     test
  //     ```
  //  3. another tag
  //     ```
  //     > test
  //      - - -
  //     ```
  for (nextLine = startLine + 1; nextLine < endLine; nextLine++) {
    if (state.sCount[nextLine] < oldIndent) { break; }

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

    if (pos >= max) {
      // Case 1: line is not inside the blockquote, and this line is empty.
      break;
    }

    if (state.src.charCodeAt(pos++) === 0x3E/* > */) {
      // This line is inside the blockquote.

      // skip one optional space (but not tab, check cmark impl) after '>'
      if (state.src.charCodeAt(pos) === 0x20) { pos++; }

      // skip spaces after ">" and re-calculate offset
      initial = offset = state.sCount[nextLine] + pos - (state.bMarks[nextLine] + state.tShift[nextLine]);

      oldBMarks.push(state.bMarks[nextLine]);
      state.bMarks[nextLine] = pos;

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

        if (isSpace(ch)) {
          if (ch === 0x09) {
            offset += 4 - offset % 4;
          } else {
            offset++;
          }
        } else {
          break;
        }

        pos++;
      }

      lastLineEmpty = pos >= max;

      oldSCount.push(state.sCount[nextLine]);
      state.sCount[nextLine] = offset - initial;

      oldTShift.push(state.tShift[nextLine]);
      state.tShift[nextLine] = pos - state.bMarks[nextLine];
      continue;
    }

    // Case 2: line is not inside the blockquote, and the last line was empty.
    if (lastLineEmpty) { break; }

    // Case 3: another tag 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; }

    oldBMarks.push(state.bMarks[nextLine]);
    oldTShift.push(state.tShift[nextLine]);
    oldSCount.push(state.sCount[nextLine]);

    // A negative indentation means that this is a paragraph continuation
    //
    state.sCount[nextLine] = -1;
  }

  oldParentType = state.parentType;
  state.parentType = 'blockquote';

  token        = state.push('blockquote_open', 'blockquote', 1);
  token.markup = '>';
  token.map    = lines = [ startLine, 0 ];

  state.md.block.tokenize(state, startLine, nextLine);

  token        = state.push('blockquote_close', 'blockquote', -1);
  token.markup = '>';

  state.parentType = oldParentType;
  lines[1] = state.line;

  // Restore original tShift; this might not be necessary since the parser
  // has already been here, but just to make sure we can do that.
  for (i = 0; i < oldTShift.length; i++) {
    state.bMarks[i + startLine] = oldBMarks[i];
    state.tShift[i + startLine] = oldTShift[i];
    state.sCount[i + startLine] = oldSCount[i];
  }
  state.blkIndent = oldIndent;

  return true;
};