// CodeMirror, copyright © by Marijn Haverbeke and others // Distributed under an MIT license: codemirror.net/LICENSE

(function (mod) {

if (typeof exports == "object" && typeof module == "object") // CommonJS
  mod(require("../../lib/codemirror"), require("../yaml/yaml"))
else if (typeof define == "function" && define.amd) // AMD
  define(["../../lib/codemirror", "../yaml/yaml"], mod)
else // Plain browser env
  mod(CodeMirror)

})(function (CodeMirror) {

var START = 0, FRONTMATTER = 1, BODY = 2

// a mixed mode for Markdown text with an optional YAML front matter
CodeMirror.defineMode("yaml-frontmatter", function (config, parserConfig) {
  var yamlMode = CodeMirror.getMode(config, "yaml")
  var innerMode = CodeMirror.getMode(config, parserConfig && parserConfig.base || "gfm")

  function curMode(state) {
    return state.state == BODY ? innerMode : yamlMode
  }

  return {
    startState: function () {
      return {
        state: START,
        inner: CodeMirror.startState(yamlMode)
      }
    },
    copyState: function (state) {
      return {
        state: state.state,
        inner: CodeMirror.copyState(curMode(state), state.inner)
      }
    },
    token: function (stream, state) {
      if (state.state == START) {
        if (stream.match(/---/, false)) {
          state.state = FRONTMATTER
          return yamlMode.token(stream, state.inner)
        } else {
          state.state = BODY
          state.inner = CodeMirror.startState(innerMode)
          return innerMode.token(stream, state.inner)
        }
      } else if (state.state == FRONTMATTER) {
        var end = stream.sol() && stream.match(/---/, false)
        var style = yamlMode.token(stream, state.inner)
        if (end) {
          state.state = BODY
          state.inner = CodeMirror.startState(innerMode)
        }
        return style
      } else {
        return innerMode.token(stream, state.inner)
      }
    },
    innerMode: function (state) {
      return {mode: curMode(state), state: state.inner}
    },
    blankLine: function (state) {
      var mode = curMode(state)
      if (mode.blankLine) return mode.blankLine(state.inner)
    }
  }
})

});