import std/[
  collections/sequtils,
  strformat,
  strutils,
  sugar,
]
import fp/[
  option,
  resultM,
]
import fusion/matching
{.experimental: "caseStmtMacros".}
import ./org_types
import ./org_builder_api
import ../parser/parser
import ../utils/fp

# -- Parsers

let headingStarsParser* = following(@[
  ignore(optional(newline)),
  manyUntil(ch('*'), ch(' ')),
  ignore(space)
])

proc createTodoKeywordParser(xs: seq[string]): parserFnT =
  choice(xs.map((x: string) => str(x) + ignore(space)))

let todoKeywords = @["TODO"]
let doneKeywords = @["DONE"]

let parseTodoKeyword = todoKeywords.createTodoKeywordParser()
let parseDoneKeyword = doneKeywords.createTodoKeywordParser()

# let parseContentText = @[
#   anyUntil(choice(@[endOfStream, str("\n")])),
# ]

# let parseHeadlineNewline = @[
#   choice(@[
#     ch(NewLines),
#     endOfStream,
#   ])
# ]

# let parseHeadingText = @[
#   anyUntil(newline),
# ]

# -- Tokenizers

let buildStars = func(tokens: seq[ParserToken], org: OrgBlock): OrgBlock {.closure.}=
  org.level = tokens.len
  org

# let buildTodo = func(tokens: seq[ParserToken], org: OrgBlock): OrgBlock {.closure.}=
#   org.todo = tokens.tokensToString().some()
#   org

# let buildHeadlineContent = func(tokens: seq[ParserToken], org: OrgBlock): OrgBlock {.closure.}=
#   let headlineString = tokens.tokensToString()

#   let tokens = tryBuildInline(headlineString)
#   .fold(
#     x => newSeq[OrgInlineBuilderT](),
#     (x: OrgInlineBuilder) => x.tree,
#   )

#   org.headlineContent = tokens
#   org

# let buildHeadlineChildren = func(tokens: seq[ParserToken], org: OrgBlock): OrgBlock {.closure.}=
#   # let headlineString = tokens.tokensToString()

#   org

# let buildHeadlineNewline = func(tokens: seq[ParserToken], org: OrgBlock): OrgBlock {.closure.}=
#   org

# proc tryBuildHeading(builder: OrgBuilderResult): OrgBuilderResult =
#   # echo builder
#   builder
#   .applyParsersSeqToSingle(
#     OrgBlock(kind: orgHeading),
#     @[
#       (parseHeadingStars, buildStars, false),

#       (@[optional(parseTodoKeyword)], buildTodo, true),
#       (@[optional(parseDoneKeyword)], buildTodo, true),

#       (parseHeadingText, buildHeadlineContent, false),

#       # (parseContentText, buildHeadlineChildren, true),

#       (parseHeadlineNewline, buildHeadlineNewline, false),
#     ]
#   )

# let headingParser = choice(@[
#   newline + ch('*'),
#   endOfStream,
# ])


# let contentEndParser = newline

# let buildNewline = func(tokens: seq[ParserToken], org: OrgBlock): OrgBlock {.closure.} =
#   OrgBlock(
#     kind: orgNewline
#   )

# proc concatOrgBlock(xs: seq[OrgBlock], ys: seq[OrgBlock]): seq[OrgBlock] = xs & ys

# let parseBlockText = @[
#   anyUntil(choice(@[endOfStream, str("\n")])),
# ]

# let contentParsersSeq: seq[tuple[
#   parsers: seq[Parser -> ParserResult],
#   tokenFoldFn: (seq[ParserToken], OrgBlock) -> OrgBlock,
#   ignoreEmpty: bool,
#   # concatFn: (seq[OrgBlock], seq[OrgBlock]) -> seq[OrgBlock],
# ]] = @[
#   (parseBlockText, buildNewline, true),
#   (contentEndParser, buildNewline, true),
# ]

# proc parseHeadlineChildren(builder: OrgBuilder): OrgBuilderResult =
#   var headingBlock = builder.tree[0]

#   # echo "Builder " & $builder

#   # var builderAcc: OrgBuilderResult = OrgBuilderResult.ok(builder)
#   var builderAcc: OrgBuilderResult = OrgBuilderResult.ok(OrgBuilder(
#     (
#       parser: builder.parser,
#       tree: @[],
#   )
#   ))

#   echo "builderAcc before parse content ", builderAcc
#   # echo builderAcc.tryParser(headingParser)
#   while builderAcc.isOk() and builderAcc.tryParser(headingParser).isErr():
#     builderAcc = builderAcc
#       .applyParsersSeqToSeq(
#         contentParsersSeq
#       )
#     echo "builderAcc after parse in while loop ", builderAcc
#     # echo builderAcc


#   let content = builderAcc.fold(
#     (err) => 0, # newSeq[OrgBlock](),
#     (builder: OrgBuilder) => len builder.tree,
#   )

#   # echo "builderAcc" & $builderAcc
#   echo "content" & $content

#   # headingBlock.content = content

#   let res = builderAcc.fold(
#     (err) => OrgBuilderResult.err((builder, "Could not parse content")),
#     (builder: OrgBuilder) => OrgBuilderResult.ok((
#         parser: builder.parser.emptyTokens(),
#         tree: @[headingBlock],
#     ))
#   )

#   res

# proc makeOrg*(x: string): OrgBuilderResult =
#   var acc = initOrgBuilder(x)

#   while acc.isOk() and acc.tryParser(endOfStream).isErr():
#     let unsafeAcc = acc.unsafeGet()

#     let item = acc
#     .tryBuildHeading()
#     .flatMap(
#       (x: OrgBuilder) => parseHeadlineChildren(x)
#     )
#     .flatMap(
#       (x: OrgBuilder) => OrgBuilderResult.ok(OrgBuilder((
#         parser: x.parser,
#         tree: unsafeAcc.tree & x.tree,
#       )))
#     )

#     acc = item

#   acc

# proc foldOrg*(x: OrgBuilderResult): string =
#   x
#   .fold(
#     (err) => "Error" & $err,
#     (builder: OrgBuilder) => $builder.tree,
#   )
#   # echo acc.unsafeGet().tree[^1]

# when isMainModule:
#   let test1 = """* TODO Level 1"""

#   let test2 = """* TODO Level 1
# Foo
# ** DONE Level 2

# Some more content
# """

#   let test3 = """* TODO Level 1
# Foo
# """

#   let acc = makeOrg(test3).foldOrg()

#   discard acc