var emptyCharacter = '';

var Breaks = require('../options/format').Breaks;
var Spaces = require('../options/format').Spaces;

var Marker = require('../tokenizer/marker');
var Token = require('../tokenizer/token');

function supportsAfterClosingBrace(token) {
  return token[1][1] == 'background' || token[1][1] == 'transform' || token[1][1] == 'src';
}

function afterClosingBrace(token, valueIndex) {
  return token[valueIndex][1][token[valueIndex][1].length - 1] == Marker.CLOSE_ROUND_BRACKET;
}

function afterComma(token, valueIndex) {
  return token[valueIndex][1] == Marker.COMMA;
}

function afterSlash(token, valueIndex) {
  return token[valueIndex][1] == Marker.FORWARD_SLASH;
}

function beforeComma(token, valueIndex) {
  return token[valueIndex + 1] && token[valueIndex + 1][1] == Marker.COMMA;
}

function beforeSlash(token, valueIndex) {
  return token[valueIndex + 1] && token[valueIndex + 1][1] == Marker.FORWARD_SLASH;
}

function inFilter(token) {
  return token[1][1] == 'filter' || token[1][1] == '-ms-filter';
}

function disallowsSpace(context, token, valueIndex) {
  return !context.spaceAfterClosingBrace
    && supportsAfterClosingBrace(token)
    && afterClosingBrace(token, valueIndex)
    || beforeSlash(token, valueIndex)
    || afterSlash(token, valueIndex)
    || beforeComma(token, valueIndex)
    || afterComma(token, valueIndex);
}

function rules(context, tokens) {
  var store = context.store;

  for (var i = 0, l = tokens.length; i < l; i++) {
    store(context, tokens[i]);

    if (i < l - 1) {
      store(context, comma(context));
    }
  }
}

function body(context, tokens) {
  var lastPropertyAt = lastPropertyIndex(tokens);

  for (var i = 0, l = tokens.length; i < l; i++) {
    property(context, tokens, i, lastPropertyAt);
  }
}

function lastPropertyIndex(tokens) {
  var index = tokens.length - 1;

  for (; index >= 0; index--) {
    if (tokens[index][0] != Token.COMMENT) {
      break;
    }
  }

  return index;
}

function property(context, tokens, position, lastPropertyAt) {
  var store = context.store;
  var token = tokens[position];

  var propertyValue = token[2];
  var isPropertyBlock = propertyValue && propertyValue[0] === Token.PROPERTY_BLOCK;

  var needsSemicolon;
  if (context.format) {
    if (context.format.semicolonAfterLastProperty || isPropertyBlock) {
      needsSemicolon = true;
    } else if (position < lastPropertyAt) {
      needsSemicolon = true;
    } else {
      needsSemicolon = false;
    }
  } else {
    needsSemicolon = position < lastPropertyAt || isPropertyBlock;
  }

  var isLast = position === lastPropertyAt;

  switch (token[0]) {
  case Token.AT_RULE:
    store(context, token);
    store(context, semicolon(context, Breaks.AfterProperty, false));
    break;
  case Token.AT_RULE_BLOCK:
    rules(context, token[1]);
    store(context, openBrace(context, Breaks.AfterRuleBegins, true));
    body(context, token[2]);
    store(context, closeBrace(context, Breaks.AfterRuleEnds, false, isLast));
    break;
  case Token.COMMENT:
    store(context, token);
    store(context, breakFor(context, Breaks.AfterComment) + context.indentWith);
    break;
  case Token.PROPERTY:
    store(context, token[1]);
    store(context, colon(context));
    if (propertyValue) {
      value(context, token);
    }
    store(
      context,
      needsSemicolon ? semicolon(context, Breaks.AfterProperty, isLast) : emptyCharacter
    );
    break;
  case Token.RAW:
    store(context, token);
  }
}

function value(context, token) {
  var store = context.store;
  var j, m;

  if (token[2][0] == Token.PROPERTY_BLOCK) {
    store(context, openBrace(context, Breaks.AfterBlockBegins, false));
    body(context, token[2][1]);
    store(context, closeBrace(context, Breaks.AfterBlockEnds, false, true));
  } else {
    for (j = 2, m = token.length; j < m; j++) {
      store(context, token[j]);

      if (j < m - 1 && (inFilter(token) || !disallowsSpace(context, token, j))) {
        store(context, Marker.SPACE);
      }
    }
  }
}

function breakFor(context, where) {
  return context.format ? context.format.breaks[where] : emptyCharacter;
}

function allowsSpace(context, where) {
  return context.format && context.format.spaces[where];
}

function openBrace(context, where, needsPrefixSpace) {
  if (context.format) {
    context.indentBy += context.format.indentBy;
    context.indentWith = context.format.indentWith.repeat(context.indentBy);
    return (
      needsPrefixSpace
      && allowsSpace(context, Spaces.BeforeBlockBegins) ? Marker.SPACE : emptyCharacter
    ) + Marker.OPEN_CURLY_BRACKET
      + breakFor(context, where)
      + context.indentWith;
  }
  return Marker.OPEN_CURLY_BRACKET;
}

function closeBrace(context, where, beforeBlockEnd, isLast) {
  if (context.format) {
    context.indentBy -= context.format.indentBy;
    context.indentWith = context.format.indentWith.repeat(context.indentBy);
    return (
      beforeBlockEnd
        ? breakFor(context, Breaks.BeforeBlockEnds)
        : breakFor(context, Breaks.AfterProperty)
    ) + context.indentWith
      + Marker.CLOSE_CURLY_BRACKET
      + (isLast ? emptyCharacter : breakFor(context, where) + context.indentWith);
  }
  return Marker.CLOSE_CURLY_BRACKET;
}

function colon(context) {
  return context.format
    ? Marker.COLON + (allowsSpace(context, Spaces.BeforeValue) ? Marker.SPACE : emptyCharacter)
    : Marker.COLON;
}

function semicolon(context, where, isLast) {
  return context.format
    ? Marker.SEMICOLON + (isLast ? emptyCharacter : (breakFor(context, where) + context.indentWith))
    : Marker.SEMICOLON;
}

function comma(context) {
  return context.format
    ? Marker.COMMA + breakFor(context, Breaks.BetweenSelectors) + context.indentWith
    : Marker.COMMA;
}

function all(context, tokens) {
  var store = context.store;
  var token;
  var isLast;
  var i, l;

  for (i = 0, l = tokens.length; i < l; i++) {
    token = tokens[i];
    isLast = i == l - 1;

    switch (token[0]) {
    case Token.AT_RULE:
      store(context, token);
      store(context, semicolon(context, Breaks.AfterAtRule, isLast));
      break;
    case Token.AT_RULE_BLOCK:
      rules(context, token[1]);
      store(context, openBrace(context, Breaks.AfterRuleBegins, true));
      body(context, token[2]);
      store(context, closeBrace(context, Breaks.AfterRuleEnds, false, isLast));
      break;
    case Token.NESTED_BLOCK:
      rules(context, token[1]);
      store(context, openBrace(context, Breaks.AfterBlockBegins, true));
      all(context, token[2]);
      store(context, closeBrace(context, Breaks.AfterBlockEnds, true, isLast));
      break;
    case Token.COMMENT:
      store(context, token);
      store(context, breakFor(context, Breaks.AfterComment) + context.indentWith);
      break;
    case Token.RAW:
      store(context, token);
      break;
    case Token.RULE:
      rules(context, token[1]);
      store(context, openBrace(context, Breaks.AfterRuleBegins, true));
      body(context, token[2]);
      store(context, closeBrace(context, Breaks.AfterRuleEnds, false, isLast));
      break;
    }
  }
}

module.exports = {
  all: all,
  body: body,
  property: property,
  rules: rules,
  value: value
};