import std/httpclient, std/json, std/logging, std/options, std/sequtils,
  std/strutils, std/times
import timeutils

const NOTION_MAX_PAGE_SIZE* = 100
const NOTION_DATE_FORMAT = "YYYY-MM-dd"

proc parseDate(str: string): DateTime =
  try: result = parseIso8601(str)
  except: result = times.parse(str, NOTION_DATE_FORMAT)

## Utility functions for creating Page property values
## ---------------------------------------------------

proc makeDateProp*(d: Option[DateTime]): JsonNode =
  if d.isSome: return %*{ "date": { "start": format(d.get, NOTION_DATE_FORMAT) } }
  else: return %*{ "date": nil }

proc makeDateTimeProp*(d: Option[DateTime]): JsonNode =
  if d.isSome: return %*{ "date": { "start": formatIso8601(d.get) } }
  else: return %*{ "date": nil }

proc makeIntervalProp*(s: Option[DateTime], e: Option[DateTime]): JsonNode =
  if not s.isSome: result = %*{ "date": nil }

  result = %*{ "date": { "start": formatIso8601(s.get) } }

  if e.isSome: result["date"]["end"] = %formatIso8601(e.get)

proc makeMultiSelectProp*(values: seq[string]): JsonNode =
  if values.len == 0: return %*{ "multi_select": [] }
  return %*{ "multi_select": values.mapIt(%*{ "name": it }) }

proc makeRelationProp*(ids: seq[string]): JsonNode =
  if ids.len == 0: return %*{ "relation": [] }
  return %*{ "relation": ids.mapIt(%*{ "id": it }) }

proc makeSelectProp*(value: string): JsonNode =
  return %*{ "select": { "name": value } }

proc makeTextProp*(propType: string, value: string): JsonNode =
  return %*{
    propType: [
      {
        "type": "text",
        "text": { "content": value }
      }
    ]
  }

## Utility functions for reading Page property values
## --------------------------------------------------

proc getPropNode(page: JsonNode, propType, propName: string): JsonNode =
  result = page{"properties", propName, propType}

  if isNil(result):
    raise newException(ValueError,
      "could not find a " & propType & " property named '" & propName &
      "' in the Notion page (id: " & page["id"].getStr & ")")

proc getEmail*(page: JsonNode, propName: string): string =
  let propNode = page.getPropNode("email", propName)
  return propNode.getStr

proc getMultiSelect*(page: JsonNode, propName: string): seq[string] =
  let propNode = page.getPropNode("multi_select", propName)
  return propNode.getElems.mapIt(it["name"].getStr)

proc getPhone*(page: JsonNode, propName: string): string =
  let propNode = page.getPropNode("phone_number", propName)
  return propNode.getStr

proc getRelationIds*(page: JsonNode, propName: string): seq[string] =
  let propNode = page.getPropNode("relation", propName)
  return propNode.getElems.mapIt(it["id"].getStr)

proc getText*(page: JsonNode, propName: string): string =
  let propNode = page.getPropNode("rich_text", propName)
  if propNode.len == 0: return ""
  return propNode[0]["plain_text"].getStr

proc getTitle*(page: JsonNode, propName: string): string =
  let propNode = page.getPropNode("title", propName)
  if propNode.len == 0: return ""
  return propNode[0]["plain_text"].getStr

proc getSelect*(page: JsonNode, propName: string): string =
  let propNode = page.getPropNode("select", propName)
  if propNode.kind == JNull: return ""
  return propNode["name"].getStr

proc getDateTime*(page: JsonNode, propName: string): Option[DateTime] =
  let propNode = page.getPropNode("date", propName)
  if propNode.kind == JNull: result = none[DateTime]()
  else: result = some(parseDate(propNode["start"].getStr))

proc newNotionClient*(apiVersion, integrationToken: string): HttpClient =
  return newHttpClient(headers = newHttpHeaders([
    ("Content-Type", "application/json"),
    ("Authorization", "Bearer " & integrationToken),
    ("Notion-Version", apiVersion)
  ], true))

proc fetchAllPages*(
    http: HttpClient,
    url: string,
    bodyTemplate = %*{ "page_size": NOTION_MAX_PAGE_SIZE}): seq[JsonNode] =

  result = @[]
  var nextCursor: string = ""

  while true:
    let body = parseJson($bodyTemplate)
    if not nextCursor.isEmptyOrWhitespace: body["start_cursor"] = %nextCursor

    debug "Fetching pages from database:\n\tPOST " & url & "\n\t" & $body
    let jsonResp = parseJson(http.postContent(url, $body))

    result = result & jsonResp["results"].getElems
    if jsonResp.hasKey("next_cursor") and jsonResp["next_cursor"].kind != JNull:
      nextCursor = jsonResp["next_cursor"].getStr

    if nextCursor.isEmptyOrWhitespace: break