-- | This module provides functions to display errors in a fancy way.
module App.DisplayErrors where

import Prelude (show, ($), (<>))

-- import Data.Foldable as Foldable
import Data.Maybe (Maybe(..), maybe)
import Halogen.HTML as HH

import App.Validation.DNS as ValidationDNS
import App.Validation.Label as ValidationLabel
import GenericParser.DomainParser.Common (DomainError(..)) as DomainParser
import GenericParser.IPAddress as IPAddress
import Bulma as Bulma

error_to_paragraph :: forall w i. ValidationDNS.Error -> HH.HTML w i
error_to_paragraph v = Bulma.error_message (Bulma.p $ show_error_title v)
  (case v of
      ValidationDNS.UNKNOWN              -> Bulma.p "An internal error happened."
      ValidationDNS.VEIPv4     err       -> maybe default_error show_error_ip4 err.error
      ValidationDNS.VEIPv6     err       -> maybe default_error show_error_ip6 err.error
      ValidationDNS.VEName     err       -> maybe default_error show_error_domain err.error
      ValidationDNS.VETTL min max n      -> Bulma.p $ "TTL should have a value between " <> show min <> " and " <> show max
                                         <> ", current value: " <> show n <> "."
      ValidationDNS.VETXT      err       -> maybe default_error show_error_txt err.error
      ValidationDNS.VECNAME    err       -> maybe default_error show_error_domain err.error
      ValidationDNS.VENS       err       -> maybe default_error show_error_domain err.error
      ValidationDNS.VEMX       err       -> maybe default_error show_error_domain err.error
      ValidationDNS.VEPriority min max n -> Bulma.p $ "Priority should have a value between " <> show min <> " and " <> show max
                                         <> ", current value: " <> show n <> "."
      ValidationDNS.VESRV      err       -> maybe default_error show_error_domain err.error
      ValidationDNS.VEProtocol err       -> maybe default_error show_error_protocol err.error
      ValidationDNS.VEPort min max n     -> Bulma.p $ "Port should have a value between " <> show min <> " and " <> show max
                                         <> ", current value: " <> show n <> "."
      ValidationDNS.VEWeight min max n   -> Bulma.p $ "Weight should have a value between " <> show min <> " and " <> show max
                                         <> ", current value: " <> show n <> "."

      -- SPF dedicated RR
      ValidationDNS.VESPFMechanismName err -> maybe default_error show_error_domain err.error
      ValidationDNS.VESPFMechanismIPv4 err -> maybe default_error show_error_ip4 err.error
      ValidationDNS.VESPFMechanismIPv6 err -> maybe default_error show_error_ip6 err.error
      ValidationDNS.VESPFModifierName  err -> maybe default_error show_error_domain err.error

      ValidationDNS.DKIMInvalidKeySize min max -> show_error_key_sizes min max
  )
  where default_error = Bulma.p ""

show_error_key_sizes :: forall w i. Int -> Int -> HH.HTML w i
show_error_key_sizes min max
  = Bulma.p $ "Chosen signature algorithm only accepts public key input between "
              <> show min <> " and " <> show max <> " characters."

-- | `show_error_title` provide a simple title string to display to the user in case of an error with an entry.
show_error_title :: ValidationDNS.Error -> String
show_error_title v = case v of
  ValidationDNS.UNKNOWN              -> "Unknown"
  ValidationDNS.VEIPv4     err       -> "The IPv4 address is wrong (position: "        <> show err.position <> ")"
  ValidationDNS.VEIPv6     err       -> "The IPv6 address is wrong (position: "        <> show err.position <> ")"
  ValidationDNS.VEName     err       -> "The name (domain label) is wrong (position: " <> show err.position <> ")"
  ValidationDNS.VETTL min max n      -> "Invalid TTL (min: " <> show min <> ", max: " <> show max <> ", n: " <> show n <> ")"
  ValidationDNS.VETXT      err       -> "The TXT input is wrong (position: "           <> show err.position <> ")"
  ValidationDNS.VECNAME    err       -> "The CNAME input is wrong (position: "         <> show err.position <> ")"
  ValidationDNS.VENS       err       -> "The NS input is wrong (position: "            <> show err.position <> ")"
  ValidationDNS.VEMX       err       -> "The MX target input is wrong (position: "     <> show err.position <> ")"
  ValidationDNS.VEPriority min max n -> "Invalid Priority (min: " <> show min <> ", max: " <> show max <> ", n: " <> show n <> ")"
  ValidationDNS.VESRV      err       -> "The SRV target input is wrong (position: "    <> show err.position <> ")"
  ValidationDNS.VEProtocol err       -> "The Protocol input is wrong (position: "      <> show err.position <> ")"
  ValidationDNS.VEPort min max n     -> "Invalid Port (min: " <> show min <> ", max: " <> show max <> ", n: " <> show n <> ")"
  ValidationDNS.VEWeight min max n   -> "Invalid Weight (min: " <> show min <> ", max: " <> show max <> ", n: " <> show n <> ")"

  -- SPF dedicated RR
  ValidationDNS.VESPFMechanismName err -> "The domain name in a SPF mechanism is wrong (position: " <> show err.position <> ")"
  ValidationDNS.VESPFMechanismIPv4 err -> "The IPv4 address in a SPF mechanism is wrong (position: "        <> show err.position <> ")"
  ValidationDNS.VESPFMechanismIPv6 err -> "The IPv6 address in a SPF mechanism is wrong (position: "        <> show err.position <> ")"

  ValidationDNS.VESPFModifierName err  -> "The domain name in a SPF modifier (EXP or REDIRECT) is wrong (position: " <> show err.position <> ")"
  ValidationDNS.DKIMInvalidKeySize _ _ -> "Public key has an invalid length."

show_error_domain :: forall w i. DomainParser.DomainError -> HH.HTML w i
show_error_domain e = case e of
  DomainParser.LabelTooLarge size ->
    Bulma.p $ "The label contains too many characters (" <> show size <> ")."
  DomainParser.DomainTooLarge size ->
    Bulma.p $ "The domain contains too many characters (" <> show size <> ")."
  -- DomainParser.InvalidCharacter
  -- DomainParser.EOFExpected
  _ -> Bulma.p """
           The domain (or label) contains invalid characters.
           A domain label should start with a letter,
           then eventually a series of letters, digits and hyphenations ('-'),
           and must finish with either a letter or a digit.
         """

show_error_protocol :: forall w i. ValidationDNS.ProtocolError -> HH.HTML w i
show_error_protocol e = case e of
  ValidationDNS.InvalidProtocol -> Bulma.p "Protocol should be a value as 'tcp' or 'udp'."

show_error_ip6 :: forall w i. IPAddress.IPv6Error -> HH.HTML w i
show_error_ip6 e = case e of
  IPAddress.IP6TooManyHexaDecimalCharacters ->
    Bulma.p "IP6TooManyHexaDecimalCharacters"
  IPAddress.IP6NotEnoughChunks ->
    Bulma.p """
      The IPv6 representation is erroneous, it should contain 8 groups of hexadecimal characters or
      being shortened with a double ':' character, such as '2000::1'.
      """
  IPAddress.IP6TooManyChunks ->
    Bulma.p "The IPv6 representation is erroneous. It should contain only up to 8 groups of hexadecimal characters."
  IPAddress.IP6IrrelevantShortRepresentation ->
    Bulma.p "IPv6 address has been unnecessarily shortened (with two ':')."
  IPAddress.IP6InvalidRange -> Bulma.p "IPv6 address or range isn't valid."

show_error_ip4 :: forall w i. IPAddress.IPv4Error -> HH.HTML w i
show_error_ip4 e = case e of
  IPAddress.IP4NumberTooBig n ->
    Bulma.p $ "IPv4 address contains a number too big (should be between 0 and 255). Current entered number: " <> show n
  IPAddress.IP4IrrelevantShortRepresentation ->
    Bulma.p "IPv4 address has been unnecessarily shortened (with two '.')."
  IPAddress.IP4InvalidRange -> Bulma.p "IPv4 address or range isn't valid."

show_error_txt :: forall w i. ValidationDNS.TXTError -> HH.HTML w i
show_error_txt e = case e of
  ValidationDNS.TXTInvalidCharacter -> Bulma.p "The TXT field contains some invalid characters."
  ValidationDNS.TXTTooLong max n ->
    Bulma.p $ "An TXT field is limited to " <> show max <> " characters (currently there are "
              <> show n <> " characters)."

domainerror_string :: DomainParser.DomainError -> String
domainerror_string (DomainParser.LabelTooLarge size)  = "LabelTooLarge (size: " <> show size <> ")"
domainerror_string (DomainParser.DomainTooLarge size) = "DomainTooLarge (size: " <> show size <> ")"
domainerror_string (DomainParser.InvalidCharacter)    = "InvalidCharacter"
domainerror_string (DomainParser.EOFExpected)         = "EOFExpected"

-- | This `error_to_paragraph` is designed to go along the `Validation.Label` module.
error_to_paragraph_label :: forall w i. ValidationLabel.Error -> HH.HTML w i
error_to_paragraph_label v = Bulma.error_message (Bulma.p $ show_error_title_label v)
  (case v of
    ValidationLabel.ParsingError x -> case x.error of
      Nothing -> Bulma.p ""
      Just (ValidationLabel.CannotParse err) -> show_error_domain err
      Just (ValidationLabel.CannotEntirelyParse) -> Bulma.p "Cannot entirely parse the label."
      Just (ValidationLabel.Size min max n) ->
        Bulma.p $ "Label size should be between " <> show min <> " and " <> show max
                  <> " (current size: " <> show n <> ")."
  )

show_error_title_label :: ValidationLabel.Error -> String
show_error_title_label v = case v of
  ValidationLabel.ParsingError x -> case x.error of
    Nothing -> "Cannot parse the label (position: " <> show x.position <> ")."
    Just (ValidationLabel.CannotParse _) ->
      "Cannot parse the label (position: " <> show x.position <> ")."
    Just (ValidationLabel.CannotEntirelyParse) -> "Cannot entirely parse the label."
    Just (ValidationLabel.Size min max n) ->
      "Label size should be between " <> show min <> " and " <> show max
      <> " (current size: " <> show n <> ")."