#            NimYAML - YAML implementation in Nim
#        (c) Copyright 2015 Felix Krause
#
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.

import "../yaml"

proc escapeNewlines(s: string): string =
  result = ""
  for c in s:
    case c
    of '\l': result.add("\\n")
    of '\t': result.add("\\t")
    of '\\': result.add("\\\\")
    else: result.add(c)

proc printDifference*(expected, actual: YamlStreamEvent) =
  if expected.kind != actual.kind:
    echo "expected " & $expected.kind & ", got " & $actual.kind
  else:
    case expected.kind
    of yamlScalar:
      if expected.scalarTag != actual.scalarTag:
        echo "[\"", actual.scalarContent, "\".tag] expected tag ",
             expected.scalarTag, ", got ", actual.scalarTag
      elif expected.scalarAnchor != actual.scalarAnchor:
        echo "[scalarEvent] expected anchor ", expected.scalarAnchor,
             ", got ", actual.scalarAnchor
      elif expected.scalarContent != actual.scalarContent:
        let msg = "[scalarEvent] content mismatch!\nexpected: " &
              escapeNewlines(expected.scalarContent) &
              "\ngot     : " & escapeNewlines(actual.scalarContent)
        if expected.scalarContent.len != actual.scalarContent.len:
          echo msg, "\n(length does not match)"
        else:
          for i in 0..expected.scalarContent.high:
            if expected.scalarContent[i] != actual.scalarContent[i]:
              echo msg, "\n(first different char at pos ", i, ": expected ",
                   cast[int](expected.scalarContent[i]), ", got ",
                  cast[int](actual.scalarContent[i]), ")"
              break
      else: echo "[scalarEvent] Unknown difference"
    of yamlStartMap:
      if expected.mapTag != actual.mapTag:
        echo "[map.tag] expected ", expected.mapTag, ", got ", actual.mapTag
      elif expected.mapAnchor != actual.mapAnchor:
        echo "[map.anchor] expected ", expected.mapAnchor, ", got ",
            actual.mapAnchor
      else: echo "[map.tag] Unknown difference"
    of yamlStartSeq:
      if expected.seqTag != actual.seqTag:
        echo "[seq.tag] expected ", expected.seqTag, ", got ", actual.seqTag
      elif expected.seqAnchor != actual.seqAnchor:
        echo "[seq.anchor] expected ", expected.seqAnchor, ", got ",
            actual.seqAnchor
      else: echo "[seq] Unknown difference"
    of yamlAlias:
      if expected.aliasTarget != actual.aliasTarget:
        echo "[alias] expected ", expected.aliasTarget, ", got ",
           actual.aliasTarget
      else: echo "[alias] Unknown difference"
    else: echo "Unknown difference in event kind " & $expected.kind

template ensure*(input: var YamlStream,
                 expected: varargs[YamlStreamEvent]) {.dirty.} =
  var i = 0
  for token in input:
    if i >= expected.len:
      echo "received more tokens than expected (next token = ", token.kind, ")"
      fail()
      break
    if token != expected[i]:
      echo "at token #" & $i & ":"
      printDifference(expected[i], token)
      fail()
      break
    i.inc()