// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict';

module.exports = doJSON;

// Take the lexed input, and return a JSON-encoded object.
// A module looks like this: https://gist.github.com/1777387.

const common = require('./common.js');
const marked = require('marked');

// Customized heading without id attribute.
const renderer = new marked.Renderer();
renderer.heading = function(text, level) {
  return `<h${level}>${text}</h${level}>\n`;
};
marked.setOptions({
  renderer: renderer
});

function doJSON(input, filename, cb) {
  const root = { source: filename };
  const stack = [root];
  var depth = 0;
  var current = root;
  var state = null;
  const lexed = marked.lexer(input);
  lexed.forEach(function(tok) {
    const type = tok.type;
    var text = tok.text;

    // <!-- type = module -->
    // This is for cases where the markdown semantic structure is lacking.
    if (type === 'paragraph' || type === 'html') {
      var metaExpr = /<!--([^=]+)=([^-]+)-->\n*/g;
      text = text.replace(metaExpr, function(_0, k, v) {
        current[k.trim()] = v.trim();
        return '';
      });
      text = text.trim();
      if (!text) return;
    }

    if (type === 'heading' &&
        !text.trim().match(/^example/i)) {
      if (tok.depth - depth > 1) {
        return cb(new Error('Inappropriate heading level\n' +
                            JSON.stringify(tok)));
      }

      // Sometimes we have two headings with a single blob of description.
      // Treat as a clone.
      if (current &&
          state === 'AFTERHEADING' &&
          depth === tok.depth) {
        var clone = current;
        current = newSection(tok);
        current.clone = clone;
        // Don't keep it around on the stack.
        stack.pop();
      } else {
        // If the level is greater than the current depth,
        // then it's a child, so we should just leave the stack as it is.
        // However, if it's a sibling or higher, then it implies
        // the closure of the other sections that came before.
        // root is always considered the level=0 section,
        // and the lowest heading is 1, so this should always
        // result in having a valid parent node.
        var d = tok.depth;
        while (d <= depth) {
          finishSection(stack.pop(), stack[stack.length - 1]);
          d++;
        }
        current = newSection(tok);
      }

      depth = tok.depth;
      stack.push(current);
      state = 'AFTERHEADING';
      return;
    }

    // Immediately after a heading, we can expect the following:
    //
    // { type: 'blockquote_start' },
    // { type: 'paragraph', text: 'Stability: ...' },
    // { type: 'blockquote_end' },
    //
    // A list: starting with list_start, ending with list_end,
    // maybe containing other nested lists in each item.
    //
    // If one of these isn't found, then anything that comes
    // between here and the next heading should be parsed as the desc.
    var stability;
    if (state === 'AFTERHEADING') {
      if (type === 'blockquote_start') {
        state = 'AFTERHEADING_BLOCKQUOTE';
        return;
      } else if (type === 'list_start' && !tok.ordered) {
        state = 'AFTERHEADING_LIST';
        current.list = current.list || [];
        current.list.push(tok);
        current.list.level = 1;
      } else if (type === 'html' && common.isYAMLBlock(tok.text)) {
        current.meta = common.extractAndParseYAML(tok.text);
      } else {
        current.desc = current.desc || [];
        if (!Array.isArray(current.desc)) {
          current.shortDesc = current.desc;
          current.desc = [];
        }
        current.desc.links = lexed.links;
        current.desc.push(tok);
        state = 'DESC';
      }
      return;
    }

    if (state === 'AFTERHEADING_LIST') {
      current.list.push(tok);
      if (type === 'list_start') {
        current.list.level++;
      } else if (type === 'list_end') {
        current.list.level--;
      }
      if (current.list.level === 0) {
        state = 'AFTERHEADING';
        processList(current);
      }
      return;
    }

    if (state === 'AFTERHEADING_BLOCKQUOTE') {
      if (type === 'blockquote_end') {
        state = 'AFTERHEADING';
        return;
      }

      if (type === 'paragraph' &&
          (stability = text.match(/^Stability: ([0-5])(?:\s*-\s*)?(.*)$/))) {
        current.stability = parseInt(stability[1], 10);
        current.stabilityText = stability[2].trim();
        return;
      }
    }

    current.desc = current.desc || [];
    current.desc.links = lexed.links;
    current.desc.push(tok);

  });

  // Finish any sections left open.
  while (root !== (current = stack.pop())) {
    finishSection(current, stack[stack.length - 1]);
  }

  return cb(null, root);
}


// Go from something like this:
//
// [ { type: 'list_item_start' },
//   { type: 'text',
//     text: '`settings` Object, Optional' },
//   { type: 'list_start', ordered: false },
//   { type: 'list_item_start' },
//   { type: 'text',
//     text: 'exec: String, file path to worker file. Default: `__filename`' },
//   { type: 'list_item_end' },
//   { type: 'list_item_start' },
//   { type: 'text',
//     text: 'args: Array, string arguments passed to worker.' },
//   { type: 'text',
//     text: 'Default: `process.argv.slice(2)`' },
//   { type: 'list_item_end' },
//   { type: 'list_item_start' },
//   { type: 'text',
//     text: 'silent: Boolean, whether to send output to parent\'s stdio.' },
//   { type: 'text', text: 'Default: `false`' },
//   { type: 'space' },
//   { type: 'list_item_end' },
//   { type: 'list_end' },
//   { type: 'list_item_end' },
//   { type: 'list_end' } ]
//
// to something like:
//
// [ { name: 'settings',
//     type: 'object',
//     optional: true,
//     settings:
//      [ { name: 'exec',
//          type: 'string',
//          desc: 'file path to worker file',
//          default: '__filename' },
//        { name: 'args',
//          type: 'array',
//          default: 'process.argv.slice(2)',
//          desc: 'string arguments passed to worker.' },
//        { name: 'silent',
//          type: 'boolean',
//          desc: 'whether to send output to parent\'s stdio.',
//          default: 'false' } ] } ]

function processList(section) {
  const list = section.list;
  const values = [];
  var current;
  const stack = [];

  // For now, *just* build the hierarchical list.
  list.forEach(function(tok) {
    const type = tok.type;
    if (type === 'space') return;
    if (type === 'list_item_start' || type === 'loose_item_start') {
      var n = {};
      if (!current) {
        values.push(n);
        current = n;
      } else {
        current.options = current.options || [];
        stack.push(current);
        current.options.push(n);
        current = n;
      }
    } else if (type === 'list_item_end') {
      if (!current) {
        throw new Error('invalid list - end without current item\n' +
                        `${JSON.stringify(tok)}\n` +
                        JSON.stringify(list));
      }
      current = stack.pop();
    } else if (type === 'text') {
      if (!current) {
        throw new Error('invalid list - text without current item\n' +
                        `${JSON.stringify(tok)}\n` +
                        JSON.stringify(list));
      }
      current.textRaw = `${current.textRaw || ''}${tok.text} `;
    }
  });

  // Shove the name in there for properties,
  // since they are always just going to be the value etc.
  if (section.type === 'property' && values[0]) {
    values[0].textRaw = `\`${section.name}\` ${values[0].textRaw}`;
  }

  // Now pull the actual values out of the text bits.
  values.forEach(parseListItem);

  // Now figure out what this list actually means.
  // Depending on the section type, the list could be different things.

  switch (section.type) {
    case 'ctor':
    case 'classMethod':
    case 'method':
      // Each item is an argument, unless the name is 'return',
      // in which case it's the return value.
      section.signatures = section.signatures || [];
      var sig = {};
      section.signatures.push(sig);
      sig.params = values.filter(function(v) {
        if (v.name === 'return') {
          sig.return = v;
          return false;
        }
        return true;
      });
      parseSignature(section.textRaw, sig);
      break;

    case 'property':
      // There should be only one item, which is the value.
      // Copy the data up to the section.
      var value = values[0] || {};
      delete value.name;
      section.typeof = value.type || section.typeof;
      delete value.type;
      Object.keys(value).forEach(function(k) {
        section[k] = value[k];
      });
      break;

    case 'event':
      // Event: each item is an argument.
      section.params = values;
      break;

    default:
      if (section.list.length > 0) {
        section.desc = section.desc || [];
        for (var i = 0; i < section.list.length; i++) {
          section.desc.push(section.list[i]);
        }
      }
  }

  // section.listParsed = values;
  delete section.list;
}

const paramExpr = /\((.*)\);?$/;

// textRaw = "someobject.someMethod(a[, b=100][, c])"
function parseSignature(text, sig) {
  var params = text.match(paramExpr);
  if (!params) return;
  params = params[1];
  params = params.split(/,/);
  var optionalLevel = 0;
  const optionalCharDict = { '[': 1, ' ': 0, ']': -1 };
  params.forEach(function(p, i) {
    p = p.trim();
    if (!p) return;
    var param = sig.params[i];
    var optional = false;
    var def;

    // For grouped optional params such as someMethod(a[, b[, c]]).
    var pos;
    for (pos = 0; pos < p.length; pos++) {
      if (optionalCharDict[p[pos]] === undefined) { break; }
      optionalLevel += optionalCharDict[p[pos]];
    }
    p = p.substring(pos);
    optional = (optionalLevel > 0);
    for (pos = p.length - 1; pos >= 0; pos--) {
      if (optionalCharDict[p[pos]] === undefined) { break; }
      optionalLevel += optionalCharDict[p[pos]];
    }
    p = p.substring(0, pos + 1);

    const eq = p.indexOf('=');
    if (eq !== -1) {
      def = p.substr(eq + 1);
      p = p.substr(0, eq);
    }
    if (!param) {
      param = sig.params[i] = { name: p };
    }
    // At this point, the name should match.
    if (p !== param.name) {
      console.error('Warning: invalid param "%s"', p);
      console.error(` > ${JSON.stringify(param)}`);
      console.error(` > ${text}`);
    }
    if (optional) param.optional = true;
    if (def !== undefined) param.default = def;
  });
}


function parseListItem(item) {
  if (item.options) item.options.forEach(parseListItem);
  if (!item.textRaw) return;

  // The goal here is to find the name, type, default, and optional.
  // Anything left over is 'desc'.
  var text = item.textRaw.trim();
  // text = text.replace(/^(Argument|Param)s?\s*:?\s*/i, '');

  text = text.replace(/^, /, '').trim();
  const retExpr = /^returns?\s*:?\s*/i;
  const ret = text.match(retExpr);
  if (ret) {
    item.name = 'return';
    text = text.replace(retExpr, '');
  } else {
    var nameExpr = /^['`"]?([^'`": {]+)['`"]?\s*:?\s*/;
    var name = text.match(nameExpr);
    if (name) {
      item.name = name[1];
      text = text.replace(nameExpr, '');
    }
  }

  text = text.trim();
  const defaultExpr = /\(default\s*[:=]?\s*['"`]?([^, '"`]*)['"`]?\)/i;
  const def = text.match(defaultExpr);
  if (def) {
    item.default = def[1];
    text = text.replace(defaultExpr, '');
  }

  text = text.trim();
  const typeExpr = /^\{([^}]+)\}/;
  const type = text.match(typeExpr);
  if (type) {
    item.type = type[1];
    text = text.replace(typeExpr, '');
  }

  text = text.trim();
  const optExpr = /^Optional\.|(?:, )?Optional$/;
  const optional = text.match(optExpr);
  if (optional) {
    item.optional = true;
    text = text.replace(optExpr, '');
  }

  text = text.replace(/^\s*-\s*/, '');
  text = text.trim();
  if (text) item.desc = text;
}


function finishSection(section, parent) {
  if (!section || !parent) {
    throw new Error('Invalid finishSection call\n' +
                    `${JSON.stringify(section)}\n` +
                    JSON.stringify(parent));
  }

  if (!section.type) {
    section.type = 'module';
    if (parent && (parent.type === 'misc')) {
      section.type = 'misc';
    }
    section.displayName = section.name;
    section.name = section.name.toLowerCase()
      .trim().replace(/\s+/g, '_');
  }

  if (section.desc && Array.isArray(section.desc)) {
    section.desc.links = section.desc.links || [];
    section.desc = marked.parser(section.desc);
  }

  if (!section.list) section.list = [];
  processList(section);

  // Classes sometimes have various 'ctor' children
  // which are actually just descriptions of a constructor class signature.
  // Merge them into the parent.
  if (section.type === 'class' && section.ctors) {
    section.signatures = section.signatures || [];
    var sigs = section.signatures;
    section.ctors.forEach(function(ctor) {
      ctor.signatures = ctor.signatures || [{}];
      ctor.signatures.forEach(function(sig) {
        sig.desc = ctor.desc;
      });
      sigs.push.apply(sigs, ctor.signatures);
    });
    delete section.ctors;
  }

  // Properties are a bit special.
  // Their "type" is the type of object, not "property".
  if (section.properties) {
    section.properties.forEach(function(p) {
      if (p.typeof) p.type = p.typeof;
      else delete p.type;
      delete p.typeof;
    });
  }

  // Handle clones.
  if (section.clone) {
    var clone = section.clone;
    delete section.clone;
    delete clone.clone;
    deepCopy(section, clone);
    finishSection(clone, parent);
  }

  var plur;
  if (section.type.slice(-1) === 's') {
    plur = `${section.type}es`;
  } else if (section.type.slice(-1) === 'y') {
    plur = section.type.replace(/y$/, 'ies');
  } else {
    plur = `${section.type}s`;
  }

  // If the parent's type is 'misc', then it's just a random
  // collection of stuff, like the "globals" section.
  // Make the children top-level items.
  if (section.type === 'misc') {
    Object.keys(section).forEach(function(k) {
      switch (k) {
        case 'textRaw':
        case 'name':
        case 'type':
        case 'desc':
        case 'miscs':
          return;
        default:
          if (parent.type === 'misc') {
            return;
          }
          if (Array.isArray(k) && parent[k]) {
            parent[k] = parent[k].concat(section[k]);
          } else if (!parent[k]) {
            parent[k] = section[k];
          }
      }
    });
  }

  parent[plur] = parent[plur] || [];
  parent[plur].push(section);
}


// Not a general purpose deep copy.
// But sufficient for these basic things.
function deepCopy(src, dest) {
  Object.keys(src).filter(function(k) {
    return !dest.hasOwnProperty(k);
  }).forEach(function(k) {
    dest[k] = deepCopy_(src[k]);
  });
}

function deepCopy_(src) {
  if (!src) return src;
  if (Array.isArray(src)) {
    const c = new Array(src.length);
    src.forEach(function(v, i) {
      c[i] = deepCopy_(v);
    });
    return c;
  }
  if (typeof src === 'object') {
    const c = {};
    Object.keys(src).forEach(function(k) {
      c[k] = deepCopy_(src[k]);
    });
    return c;
  }
  return src;
}


// These parse out the contents of an H# tag.
const headingExpressions = [
  { type: 'event', re: /^Event(?::|\s)+['"]?([^"']+).*$/i },
  { type: 'class', re: /^Class:\s*([^ ]+).*$/i },
  { type: 'property', re: /^[^.[]+(\[[^\]]+\])\s*$/ },
  { type: 'property', re: /^[^.]+\.([^ .()]+)\s*$/ },
  { type: 'classMethod', re: /^class\s*method\s*:?[^.]+\.([^ .()]+)\([^)]*\)\s*$/i },
  { type: 'method', re: /^(?:[^.]+\.)?([^ .()]+)\([^)]*\)\s*$/ },
  { type: 'ctor', re: /^new ([A-Z][a-zA-Z]+)\([^)]*\)\s*$/ },
];

function newSection({ text }) {
  // Infer the type from the text.
  for (const { type, re } of headingExpressions) {
    const [, name] = text.match(re) || [];
    if (name) {
      return { textRaw: text, type, name };
    }
  }
  return { textRaw: text, name: text };
}