import gleam/erlang/process.{type Subject}
import gleam/int
import gleam/list
import gleam/option.{type Option, None, Some}
import gleam/otp/actor.{type Started}
import lustre
import lustre/attribute.{class}
import lustre/effect.{type Effect}
import lustre/element.{type Element}
import lustre/element/html
import shared/message.{type NotifyClient, type NotifyServer}
import web/components/shared.{
  step_prompt, view_input, view_named_input, view_named_keyed_input, view_yes_no,
}

pub fn component() -> lustre.App(
  #(List(#(Int, String)), message.ClientsServer),
  Model,
  Msg,
) {
  lustre.application(init, update, view)
}

pub opaque type Model {
  Model(
    state: Msg,
    answers: List(#(Int, #(String, String))),
    handler: Started(Subject(NotifyServer)),
  )
}

fn init(
  start_args: #(List(#(Int, String)), message.ClientsServer),
) -> #(Model, Effect(Msg)) {
  let #(answers, handlers) = start_args
  let #(_registry, handler) = handlers

  // Convert a "question number -> question text" array to
  // "question number" -> #("question text", "users answer" array
  // with blank user answers.
  let initial_array =
    list.filter(answers, fn(x) {
      let #(i, _) = x
      i <= 14 && i >= 0
    })
    |> list.map(fn(x) {
      let #(a, b) = x
      #(a, #(b, ""))
    })

  #(Model(Initial, initial_array, handler), effect.none())
}

pub opaque type Msg {
  Initial
  SharedMessage(message: NotifyClient)
  ReceiveName(message: String)
  AcceptName(accept: Option(String))
  GiveQuestion(name: String, question: String)
  GiveAnswer(name: String, question: Int, answer: String)
}

fn update(model: Model, msg: Msg) -> #(Model, Effect(Msg)) {
  case msg {
    Initial | SharedMessage(_) -> #(model, effect.none())
    AcceptName(None) -> #(Model(Initial, [], model.handler), effect.none())
    AcceptName(Some(name)) -> {
      #(Model(..model, state: GiveQuestion(name, "")), effect.none())
    }
    GiveQuestion(name, question) ->
      case int.parse(question) {
        Ok(question) if question >= 1 && question <= 14 -> #(
          Model(..model, state: GiveAnswer(name:, question:, answer: "")),
          effect.none(),
        )
        _ -> #(
          Model(..model, state: GiveQuestion(name:, question: "")),
          effect.none(),
        )
      }
    GiveAnswer(name, question, answer) -> {
      actor.send(
        model.handler.data,
        message.GiveSingleAnswer(name:, question:, answer:),
      )
      let new_value = case list.key_find(model.answers, question) {
        Ok(pair) -> {
          let #(a, _) = pair
          #(a, answer)
        }
        Error(_) -> #("", answer)
      }
      #(
        Model(
          ..model,
          state: GiveQuestion(name, ""),
          answers: list.key_set(model.answers, question, new_value),
        ),
        effect.none(),
      )
    }
    ReceiveName(_) -> #(Model(..model, state: msg), effect.none())
  }
}

fn view(model: Model) -> Element(Msg) {
  element.fragment([
    html.div([attribute.class("terminal-prompt")], [
      case model.state {
        Initial ->
          step_prompt(
            "Hello stranger. To join the quiz, I need to know your name",
            fn() { view_input(ReceiveName) },
          )
        ReceiveName(name) ->
          step_prompt(
            "Your name is " <> name <> "? Are you absolutely sure???",
            fn() { view_yes_no(name, AcceptName) },
          )
        GiveQuestion(name, _) ->
          step_prompt(
            "Enter the number of the question you want to answer",
            fn() { view_named_input(name, GiveQuestion) },
          )
        GiveAnswer(name, question, _) ->
          step_prompt(
            "Enter the answer to question number " <> int.to_string(question),
            fn() { view_named_keyed_input(question, name, GiveAnswer) },
          )
        _ -> html.h3([], [html.text("Waiting for next question")])
      },
    ]),
    html.div([class("terminal-header")], [
      html.div([class("terminal-status")], [
        html.span([class("status-blink")], [html.text("●")]),
        html.text(" SYSTEM READY"),
        html.span([class("ml-8")], [
          case model.state {
            Initial -> html.text("STATUS: Please input your name")
            ReceiveName(_) -> html.text("STATUS: Please validate your name")
            GiveQuestion(_, _) -> html.text("STATUS: Pick question to answer")
            GiveAnswer(_, _, _) -> html.text("STATUS: Give your answer")
            _ -> html.text("STATUS: Waiting for next question")
          },
        ]),
      ]),
    ]),
    terminal_section(model.answers, "[ACTIVE TRANSMISSIONS]", fn(answer) {
      content_cell(answer)
    }),
  ])
}

fn terminal_section(
  answers: List(#(Int, #(String, String))),
  header: String,
  extract: fn(#(Int, #(String, String))) -> Element(Msg),
) {
  html.div([attribute.class("terminal-section")], [
    html.div([attribute.class("terminal-label mb-4")], [
      html.text(header),
    ]),
    html.div([attribute.class("participants-grid")], list.map(answers, extract)),
  ])
}

fn content_cell(answer: #(Int, #(String, String))) -> Element(Msg) {
  let #(question, #(question_text, answer)) = answer
  html.div(
    [
      class("participant-box"),
    ],
    [
      html.div([class("participant-name")], [
        html.text("► " <> int.to_string(question) <> " " <> question_text),
      ]),
      html.div([class("participant-answer")], [
        html.text(answer),
      ]),
    ],
  )
}