import Elementary
import ElementaryHTMX
import Routes
import Styleguide

struct RoomPressureForm: HTML, Sendable {
  let response: RoomPressure.Response?
  let mode: RoomPressure.Mode

  init(mode: RoomPressure.Mode? = nil, response: RoomPressure.Response? = nil) {
    self.mode = mode ?? .knownAirflow
    self.response = response
  }

  var content: some HTML {
    div(.class("relative")) {
      FormHeader(label: "Room Pressure Calculator", svg: .leftRightArrow)

      // FIX: Remove when done testing.
      WarningBox(
        "This calculator is currently under construction, so it does not do anything when the form is submitted."
      )
      .attributes(.class("mb-8"))

      // Mode toggle / buttons.
      div(.class("absolute top-0 right-0 flex items-center gap-x-0")) {
        switch mode {
        case .knownAirflow:
          SecondaryButton(label: "Known Airflow")
            .attributes(.class("rounded-s-lg"))
            .attributes(.disabled, when: mode == .knownAirflow)
            .attributes(
              .hx.get(route: .roomPressure(.index(mode: .knownAirflow))),
              .hx.target("#content"),
              when: mode == .measuredPressure
            )
          PrimaryButton(label: "Measured Pressure")
            .attributes(.class("rounded-e-lg"))
            .attributes(
              .hx.get(route: .roomPressure(.index(mode: .measuredPressure))),
              .hx.target("#content"),
              when: mode == .knownAirflow
            )
        case .measuredPressure:
          PrimaryButton(label: "Known Airflow")
            .attributes(.class("rounded-s-lg"))
            .attributes(
              .hx.get(route: .roomPressure(.index(mode: .knownAirflow))),
              .hx.target("#content"),
              when: mode == .measuredPressure
            )
          SecondaryButton(label: "Measured Pressure")
            .attributes(.class("rounded-e-lg"))
            .attributes(.disabled, when: mode == .measuredPressure)
            .attributes(
              .hx.get(route: .roomPressure(.index(mode: .measuredPressure))),
              .hx.target("#content"),
              when: mode == .knownAirflow
            )
        }
      }

      Form(mode: mode)

      div(.id("result")) {
        if let response {
          RoomPressureResult(response: response)
        }
      }
    }
  }

  struct Form: HTML, Sendable {
    let mode: RoomPressure.Mode

    var content: some HTML<HTMLTag.form> {
      form {
        div(.class("space-y-6")) {
          LabeledContent(label: pressureLabel) {
            // NB: using .attributes(..., when:...) not working, so using a switch statement.
            switch mode {
            case .knownAirflow:
              Input(id: pressureID, placeholder: pressurePlaceholder)
                .attributes(
                  .type(.number), .step("0.1"), .min("0.1"), .max("3.0"), .autofocus, .required
                )
            case .measuredPressure:
              Input(id: pressureID, placeholder: pressurePlaceholder)
                .attributes(.type(.number), .step("0.1"), .min("0.1"), .autofocus, .required)
            }
          }

          DoorDetails()

          if mode == .knownAirflow {
            LabeledContent(label: "Supply Airflow (CFM)") {
              Input(id: "supplyAirflow", placeholder: "Airflow")
                .attributes(.type(.number), .step("0.1"), .min("0.1"), .required)
            }
          }

          PreferredGrilleHeight()

          div {
            SubmitButton(label: "Calculate Return Path Size")
          }
        }
      }
    }

    private var pressureLabel: String {
      switch mode {
      case .knownAirflow: return "Target Room Pressure (Pascals)"
      case .measuredPressure: return "Measured Room Pressure (Pascals)"
      }
    }

    private var pressureID: String {
      switch mode {
      case .knownAirflow: return "targetRoomPressure"
      case .measuredPressure: return "measuredRoomPressure"
      }
    }

    private var pressurePlaceholder: String {
      switch mode {
      case .knownAirflow: return "Room pressure (max 3 pa.)"
      case .measuredPressure: return "Measured pressure"
      }
    }
  }

  private struct DoorDetails: HTML, Sendable {

    var content: some HTML {
      div(.class("grid grid-cols-1 lg:grid-cols-2 gap-6")) {
        LabeledContent(label: "Door Width (in.)") {
          Input(id: "doorWidth", placeholder: "Width")
            .attributes(.type(.number), .step("0.1"), .min("0.1"), .required)
        }

        LabeledContent(label: "Door Height (in.)") {
          Input(id: "doorHeight", placeholder: "Height")
            .attributes(.type(.number), .step("0.1"), .min("0.1"), .required)
        }
      }

      LabeledContent(label: "Door Undercut (in.)") {
        Input(id: "doorUndercut", placeholder: "Undercut height")
          .attributes(.type(.number), .step("0.1"), .min("0.1"), .required)
      }
    }
  }

  private struct PreferredGrilleHeight: HTML, Sendable {

    var content: some HTML {
      InputLabel(for: "preferredGrilleHeight") { "Preferred Grille Height" }
      select(
        .id("preferredGrilleHeight"),
        .name("preferredGrilleHeight"),
        .class("w-full px-4 py-2 rounded-md border")
      ) {
        for height in RoomPressure.CommonReturnGrilleHeight.allCases {
          option(.value("\(height.rawValue)")) { height.label }
        }
      }
    }
  }
}

struct RoomPressureResult: HTML, Sendable {
  let response: RoomPressure.Response
}