// minimal terminal UI for daemon - no deps, just ANSI
import type { DaemonState, ServerRegistration } from './types'
import { getAllServers, setRoute, clearRoute, getLastActiveServer } from './registry'
import { getBootedSimulators } from './picker'
import {
  setRouteMode,
  setPendingMapping,
  clearMappingsForSimulator,
  getSimulatorMappings,
  setSimulatorMapping,
} from './server'
import colors from 'picocolors'

interface Simulator {
  name: string
  udid: string
  iosVersion?: string
}

type RouteMode = 'most-recent' | 'ask'

interface Point {
  x: number
  y: number
}

// cable is purely visual - derived from route state
interface Cable {
  serverIndex: number | null // null = disconnected/dragging
  controlPoint: Point
  velocity: Point
}

interface TUIState {
  simulators: Simulator[]
  servers: ServerRegistration[]
  // per-simulator cables keyed by simulator index
  cables: Map<number, Cable>
  // which simulator is currently being dragged (null if none)
  draggingSimIndex: number | null
  // remember mode before dragging to restore after
  modeBeforeDrag: RouteMode | null
  selectedCol: 0 | 1
  selectedRow: number
  routeMode: RouteMode
  lastRender: string
  width: number
  height: number
  simEndX: number
  serverStartX: number
  rowStartY: number
  popup: { message: string; timeout: ReturnType<typeof setTimeout> } | null
}

const CABLE_COLORS = [
  colors.green,
  colors.cyan,
  colors.magenta,
  colors.blue,
  colors.yellow,
]

const ESC = '\x1b'
const CSI = `${ESC}[`

const ansi = {
  hideCursor: `${CSI}?25l`,
  showCursor: `${CSI}?25h`,
  clearScreen: `${CSI}2J`,
  home: `${CSI}H`,
}

let tuiState: TUIState | null = null
let daemonState: DaemonState | null = null
let refreshInterval: ReturnType<typeof setInterval> | null = null
let physicsInterval: ReturnType<typeof setInterval> | null = null
let stdinListener: ((key: Buffer) => void) | null = null
let resizeListener: (() => void) | null = null

export function getRouteMode(): RouteMode {
  return tuiState?.routeMode || 'ask'
}

function calcLayout(width: number) {
  const simEndX = Math.floor(width * 0.25) // narrower sim column for more cable room
  const serverStartX = Math.floor(width * 0.65)
  return { simEndX, serverStartX }
}

function showPopup(message: string, durationMs = 2000): void {
  if (!tuiState) return
  if (tuiState.popup) {
    clearTimeout(tuiState.popup.timeout)
  }
  const timeout = setTimeout(() => {
    if (tuiState) {
      tuiState.popup = null
      render()
    }
  }, durationMs)
  tuiState.popup = { message, timeout }
  render()
}

export function startTUI(state: DaemonState): void {
  daemonState = state

  const width = process.stdout.columns || 80
  const height = process.stdout.rows || 24
  const { simEndX, serverStartX } = calcLayout(width)

  tuiState = {
    simulators: [],
    servers: [],
    cables: new Map(),
    draggingSimIndex: null,
    modeBeforeDrag: null,
    selectedCol: 0,
    selectedRow: 0,
    routeMode: 'most-recent',
    lastRender: '',
    width,
    height,
    simEndX,
    serverStartX,
    rowStartY: 5,
    popup: null,
  }

  process.stdout.write(ansi.clearScreen + ansi.home + ansi.hideCursor)

  if (process.stdin.isTTY) {
    process.stdin.setRawMode(true)
  }
  process.stdin.resume()

  let resizePending = false
  resizeListener = () => {
    if (!tuiState) return
    tuiState.width = process.stdout.columns || 80
    tuiState.height = process.stdout.rows || 24
    const layout = calcLayout(tuiState.width)
    tuiState.simEndX = layout.simEndX
    tuiState.serverStartX = layout.serverStartX
    tuiState.lastRender = ''

    if (!resizePending) {
      resizePending = true
      setImmediate(() => {
        resizePending = false
        process.stdout.write(ansi.clearScreen + ansi.home)
        render()
      })
    }
  }
  process.stdout.on('resize', resizeListener)

  stdinListener = (key: Buffer) => {
    const str = key.toString()

    if (str === '\u0003' || str === 'q') {
      stopTUI()
      process.exit(0)
    }

    if (!tuiState || !daemonState) return

    if (str === '\u001b[A') {
      // up
      tuiState.selectedRow = Math.max(0, tuiState.selectedRow - 1)
    } else if (str === '\u001b[B') {
      // down
      const max =
        tuiState.selectedCol === 0
          ? Math.max(0, tuiState.simulators.length - 1)
          : Math.max(0, tuiState.servers.length - 1)
      tuiState.selectedRow = Math.min(max, tuiState.selectedRow + 1)
    } else if (str === '\u001b[C') {
      // right
      if (tuiState.selectedCol === 0) {
        tuiState.selectedCol = 1
        tuiState.selectedRow = Math.min(
          tuiState.selectedRow,
          Math.max(0, tuiState.servers.length - 1)
        )
      }
    } else if (str === '\u001b[D') {
      // left
      if (tuiState.selectedCol === 1) {
        tuiState.selectedCol = 0
        tuiState.selectedRow = Math.min(
          tuiState.selectedRow,
          Math.max(0, tuiState.simulators.length - 1)
        )
      }
    } else if (str === ' ' || str === '\r') {
      handleAction()
    } else if (str === 'd') {
      handleDisconnect()
    } else if (str === 'm') {
      tuiState.routeMode = tuiState.routeMode === 'most-recent' ? 'ask' : 'most-recent'
      setRouteMode(tuiState.routeMode)
    } else if (str === 'b') {
      stopTUI()
      console.log(colors.dim('\nDaemon running in background.'))
      return
    }

    render()
  }

  process.stdin.on('data', stdinListener)

  // ensure terminal is restored on signals
  const signalHandler = () => {
    stopTUI()
    process.exit(0)
  }
  process.on('SIGINT', signalHandler)
  process.on('SIGTERM', signalHandler)

  physicsInterval = setInterval(updatePhysics, 50)
  refreshInterval = setInterval(refreshData, 1000)
  refreshData()
}

function getRouteKey(sim: Simulator): string {
  return `sim:${sim.udid}`
}

function handleAction(): void {
  if (!tuiState || !daemonState) return

  const isDragging = tuiState.draggingSimIndex !== null

  if (isDragging) {
    // connecting cable to a server
    if (tuiState.selectedCol === 1 && tuiState.servers.length > 0) {
      const simIndex = tuiState.draggingSimIndex!
      const sim = tuiState.simulators[simIndex]
      const serverIndex = tuiState.selectedRow
      const server = tuiState.servers[serverIndex]
      if (server && sim) {
        // set the simulator -> server mapping directly
        setSimulatorMapping(sim.udid, server.id)

        // also set pending mapping so if a NEW client identifier comes in, we learn it
        setPendingMapping(server.id, sim.udid)

        // set registry route for fallback
        setRoute(daemonState, getRouteKey(sim), server.id)

        // update cable
        const cable = tuiState.cables.get(simIndex)
        if (cable) {
          cable.serverIndex = serverIndex
        }
        tuiState.draggingSimIndex = null

        // restore mode if was auto before
        if (tuiState.modeBeforeDrag === 'most-recent') {
          tuiState.routeMode = 'most-recent'
          setRouteMode('most-recent')
        }
        tuiState.modeBeforeDrag = null
      }
    }
    return
  }

  // start dragging - pick up cable from selected simulator
  if (tuiState.selectedCol === 0 && tuiState.simulators.length > 0) {
    const simIndex = tuiState.selectedRow
    const sim = tuiState.simulators[simIndex]
    if (!sim) return

    // remember mode and switch to manual while editing
    tuiState.modeBeforeDrag = tuiState.routeMode
    if (tuiState.routeMode === 'most-recent') {
      tuiState.routeMode = 'ask'
      setRouteMode('ask')
    }

    // clear the route for this simulator
    clearRoute(daemonState, getRouteKey(sim))
    // clear TUI-learned mappings for this simulator only
    clearMappingsForSimulator(sim.udid)

    // update cable state
    let cable = tuiState.cables.get(simIndex)
    if (!cable) {
      cable = {
        serverIndex: null,
        controlPoint: { x: tuiState.simEndX + 5, y: tuiState.rowStartY + simIndex },
        velocity: { x: 0, y: 0 },
      }
      tuiState.cables.set(simIndex, cable)
    }
    cable.serverIndex = null
    cable.velocity = { x: 3, y: -2 }
    tuiState.draggingSimIndex = simIndex
  } else if (tuiState.selectedCol === 1 && tuiState.servers.length > 0) {
    // clicking on server side - find if any cable is connected here and disconnect it
    const serverIndex = tuiState.selectedRow

    // find which sim is connected to this server
    for (const [simIndex, cable] of tuiState.cables) {
      if (cable.serverIndex === serverIndex) {
        const sim = tuiState.simulators[simIndex]
        if (sim) {
          // remember mode and switch to manual while editing
          tuiState.modeBeforeDrag = tuiState.routeMode
          if (tuiState.routeMode === 'most-recent') {
            tuiState.routeMode = 'ask'
            setRouteMode('ask')
          }

          clearRoute(daemonState, getRouteKey(sim))
          cable.serverIndex = null
          cable.velocity = { x: -3, y: 2 }
          tuiState.draggingSimIndex = simIndex
        }
        break
      }
    }
  }
}

function handleDisconnect(): void {
  if (!tuiState || !daemonState) return

  // disconnect based on current selection
  if (tuiState.selectedCol === 0) {
    // disconnect the selected simulator
    const simIndex = tuiState.selectedRow
    const sim = tuiState.simulators[simIndex]
    const cable = tuiState.cables.get(simIndex)
    if (!sim || !cable || cable.serverIndex === null) return

    // switch to manual mode
    if (tuiState.routeMode === 'most-recent') {
      tuiState.routeMode = 'ask'
      setRouteMode('ask')
      showPopup('Switched to manual mode', 1500)
    }

    clearRoute(daemonState, getRouteKey(sim))
    clearMappingsForSimulator(sim.udid)
    cable.serverIndex = null
    cable.velocity = { x: -4, y: 3 }
  } else {
    // disconnect whatever is connected to the selected server
    const serverIndex = tuiState.selectedRow
    for (const [simIndex, cable] of tuiState.cables) {
      if (cable.serverIndex === serverIndex) {
        const sim = tuiState.simulators[simIndex]
        if (sim) {
          // switch to manual mode
          if (tuiState.routeMode === 'most-recent') {
            tuiState.routeMode = 'ask'
            setRouteMode('ask')
            showPopup('Switched to manual mode', 1500)
          }

          clearRoute(daemonState, getRouteKey(sim))
          clearMappingsForSimulator(sim.udid)
          cable.serverIndex = null
          cable.velocity = { x: -4, y: 3 }
        }
        break
      }
    }
  }
}

function updatePhysics(): void {
  if (!tuiState) return

  const gravity = 0.3
  const damping = 0.85
  let needsRender = false

  for (const [simIndex, cable] of tuiState.cables) {
    const simY = tuiState.rowStartY + simIndex

    if (cable.serverIndex !== null) {
      // connected - settle into catenary with variable sag
      // sag goes: high (0) -> low (4) -> high again (8+)
      const sagCurve = (i: number) => {
        if (i <= 4) return 6 - i // 6, 5, 4, 3, 2
        return 2 + (i - 4) * 0.8 // 2.8, 3.6, 4.4, ...
      }
      const sag = sagCurve(simIndex)

      const serverY = tuiState.rowStartY + cable.serverIndex
      const targetX = (tuiState.simEndX + tuiState.serverStartX) / 2
      const targetY = (simY + serverY) / 2 + sag

      const dx = targetX - cable.controlPoint.x
      const dy = targetY - cable.controlPoint.y

      cable.velocity.x += dx * 0.15
      cable.velocity.y += dy * 0.15
      cable.velocity.x *= damping
      cable.velocity.y *= damping

      cable.controlPoint.x += cable.velocity.x
      cable.controlPoint.y += cable.velocity.y

      if (Math.abs(cable.velocity.x) > 0.05 || Math.abs(cable.velocity.y) > 0.05) {
        needsRender = true
      }
    } else {
      // disconnected - swing with gravity
      cable.velocity.y += gravity
      cable.velocity.x *= damping
      cable.velocity.y *= damping

      cable.controlPoint.x += cable.velocity.x
      cable.controlPoint.y += cable.velocity.y

      // constrain
      const anchorX = tuiState.simEndX
      const anchorY = simY
      if (cable.controlPoint.x < anchorX) {
        cable.controlPoint.x = anchorX
        cable.velocity.x = Math.abs(cable.velocity.x) * 0.5
      }
      if (cable.controlPoint.x > tuiState.serverStartX) {
        cable.controlPoint.x = tuiState.serverStartX
        cable.velocity.x = -Math.abs(cable.velocity.x) * 0.5
      }
      if (cable.controlPoint.y < anchorY) {
        cable.controlPoint.y = anchorY
        cable.velocity.y = Math.abs(cable.velocity.y) * 0.3
      }
      if (cable.controlPoint.y > tuiState.height - 5) {
        cable.controlPoint.y = tuiState.height - 5
        cable.velocity.y = -Math.abs(cable.velocity.y) * 0.5
      }

      needsRender = true
    }
  }

  if (needsRender) render()
}

async function refreshData(): Promise<void> {
  if (!tuiState || !daemonState) return

  const newSims = await getBootedSimulators()
  const newServers = getAllServers(daemonState)

  tuiState.simulators = newSims
  tuiState.servers = newServers

  // get actual simulator -> server mappings from routing state
  const simMappings = getSimulatorMappings()

  // sync each simulator's cable with actual routing state
  for (let simIndex = 0; simIndex < newSims.length; simIndex++) {
    const sim = newSims[simIndex]

    // check if we have a known mapping for this simulator
    const mappedServerId = simMappings.get(sim.udid)
    let routedServerIndex: number | null = null
    if (mappedServerId) {
      routedServerIndex = newServers.findIndex((s) => s.id === mappedServerId)
      if (routedServerIndex === -1) routedServerIndex = null
    }

    // get or create cable for this simulator
    let cable = tuiState.cables.get(simIndex)
    if (!cable) {
      cable = {
        serverIndex: routedServerIndex,
        controlPoint: { x: tuiState.simEndX + 5, y: tuiState.rowStartY + simIndex },
        velocity: { x: 0, y: 0 },
      }
      tuiState.cables.set(simIndex, cable)
    }

    // sync visual state with actual routing state (unless this sim is being dragged)
    if (tuiState.draggingSimIndex !== simIndex) {
      if (routedServerIndex !== cable.serverIndex) {
        cable.serverIndex = routedServerIndex
        // give it a little bounce when connection changes
        if (routedServerIndex !== null) {
          cable.velocity = { x: 0, y: -2 }
        }
      }
    }
  }

  // remove cables for simulators that no longer exist
  for (const simIndex of tuiState.cables.keys()) {
    if (simIndex >= newSims.length) {
      tuiState.cables.delete(simIndex)
    }
  }

  // clamp selection
  if (tuiState.selectedCol === 0) {
    tuiState.selectedRow = Math.min(tuiState.selectedRow, Math.max(0, newSims.length - 1))
  } else {
    tuiState.selectedRow = Math.min(
      tuiState.selectedRow,
      Math.max(0, newServers.length - 1)
    )
  }

  render()
}

function render(): void {
  if (!tuiState) return

  const { width, height, simEndX, serverStartX } = tuiState
  const lines: string[] = []

  // header
  const title = ' one daemon '
  const headerPad = Math.max(0, width - title.length - 10)
  lines.push(colors.cyan(`┌─${title}${'─'.repeat(headerPad)}─:8081─┐`))

  // toggle switch row
  const isAuto = tuiState.routeMode === 'most-recent'
  const toggleLeft = isAuto ? colors.green('▶') : colors.dim('▷')
  const toggleRight = isAuto ? colors.dim('◁') : colors.yellow('◀')
  const autoLabel = isAuto ? colors.green('AUTO') : colors.dim('auto')
  const askLabel = isAuto ? colors.dim('ask') : colors.yellow('ASK')
  const toggle = `  ${autoLabel} ${toggleLeft}═══${toggleRight} ${askLabel}  [m] toggle`
  const togglePad = Math.max(0, width - stripAnsi(toggle).length - 2)
  lines.push(colors.cyan('│') + toggle + ' '.repeat(togglePad) + colors.cyan('│'))

  // column headers
  const simHeader = ' SIMULATORS'
  const srvHeader = 'SERVERS '
  const gap = ' '.repeat(Math.max(0, serverStartX - simEndX))
  lines.push(
    colors.cyan('│') +
      colors.bold(simHeader.padEnd(simEndX - 1)) +
      gap +
      colors.bold(srvHeader.padStart(width - serverStartX - 1)) +
      colors.cyan('│')
  )

  // separator
  lines.push(colors.cyan('│') + colors.dim('─'.repeat(width - 2)) + colors.cyan('│'))

  // content area
  const contentRows = height - 7
  for (let row = 0; row < contentRows; row++) {
    const y = tuiState.rowStartY + row
    let line = ''

    line += colors.cyan('│')

    // sim column - right aligned with dot on right
    const sim = tuiState.simulators[row]
    let simText = ''
    if (sim) {
      const isSelected = tuiState.selectedCol === 0 && tuiState.selectedRow === row
      const cable = tuiState.cables.get(row)
      const hasConnection = cable?.serverIndex !== null
      const cableColor = CABLE_COLORS[row % CABLE_COLORS.length]
      const plug = hasConnection ? cableColor('●') : colors.dim('○')
      const name = truncate(sim.name, simEndX - 5)
      simText = `${name} ${plug}`
      if (isSelected) simText = colors.inverse(simText)
    }
    // right-align the sim text
    const simTextLen = stripAnsi(simText).length
    const simPad = Math.max(0, simEndX - 1 - simTextLen)
    line += ' '.repeat(simPad) + simText

    // cable zone
    let cableZone = ''
    for (let x = simEndX; x < serverStartX; x++) {
      const char = getCableCharAt(x, y)
      cableZone += char || ' '
    }
    line += cableZone

    // server column - dot and folder left, port right-aligned bold yellow
    const server = tuiState.servers[row]
    let srvLeft = ''
    let srvRight = ''
    if (server) {
      const isSelected = tuiState.selectedCol === 1 && tuiState.selectedRow === row
      let connectedColor: ((s: string) => string) | null = null
      for (const [simIndex, cable] of tuiState.cables) {
        if (cable.serverIndex === row) {
          connectedColor = CABLE_COLORS[simIndex % CABLE_COLORS.length]
          break
        }
      }
      const lastActive = daemonState ? getLastActiveServer(daemonState) : null
      const isLastActive = lastActive?.id === server.id
      const plug = connectedColor ? connectedColor('●') : colors.dim('○')
      const star = isLastActive ? colors.yellow('★') : ' '
      const shortRoot = truncate(
        server.root.replace(process.env.HOME || '', '~'),
        width - serverStartX - 14
      )
      srvLeft = `${plug} ${star}${shortRoot}`
      srvRight = colors.bold(colors.yellow(`:${server.port}`))
      if (isSelected) {
        srvLeft = colors.inverse(srvLeft)
        srvRight = colors.inverse(srvRight)
      }
    }
    const srvLeftLen = stripAnsi(srvLeft).length
    const srvRightLen = stripAnsi(srvRight).length
    const srvColWidth = width - serverStartX - 2
    const srvGap = Math.max(1, srvColWidth - srvLeftLen - srvRightLen)
    line += srvLeft + ' '.repeat(srvGap) + srvRight

    line += colors.cyan('│')
    lines.push(line)
  }

  // popup or help
  if (tuiState.popup) {
    const msg = tuiState.popup.message
    const padLeft = Math.floor((width - msg.length - 4) / 2)
    const padRight = width - msg.length - padLeft - 4
    lines.push(
      colors.cyan('│') +
        ' '.repeat(Math.max(0, padLeft)) +
        colors.bgYellow(colors.black(` ${msg} `)) +
        ' '.repeat(Math.max(0, padRight)) +
        colors.cyan('│')
    )
  } else {
    lines.push(
      colors.cyan('│') +
        colors
          .dim(' ↑↓ select  ←→ move  space grab/plug  d disconnect  b bg  q quit')
          .padEnd(width - 2) +
        colors.cyan('│')
    )
  }

  // footer
  lines.push(colors.cyan(`└${'─'.repeat(width - 2)}┘`))

  const output = lines.join('\n')
  if (output !== tuiState.lastRender) {
    tuiState.lastRender = output
    process.stdout.write(ansi.home + output)
  }
}

function getCableCharAt(x: number, y: number): string | null {
  if (!tuiState) return null
  if (tuiState.simulators.length === 0) return null

  // check each cable
  for (const [simIndex, cable] of tuiState.cables) {
    const startX = tuiState.simEndX
    const startY = tuiState.rowStartY + simIndex

    let endX: number, endY: number
    if (cable.serverIndex !== null) {
      endX = tuiState.serverStartX
      endY = tuiState.rowStartY + cable.serverIndex
    } else {
      endX = Math.round(cable.controlPoint.x)
      endY = Math.round(cable.controlPoint.y)
    }

    const ctrlX = Math.round(cable.controlPoint.x)
    const ctrlY = Math.round(cable.controlPoint.y)

    // sample bezier curve
    const steps = 30
    for (let i = 0; i <= steps; i++) {
      const t = i / steps
      const invT = 1 - t

      const px = Math.round(invT * invT * startX + 2 * invT * t * ctrlX + t * t * endX)
      const py = Math.round(invT * invT * startY + 2 * invT * t * ctrlY + t * t * endY)

      if (px === x && py === y) {
        const connected = cable.serverIndex !== null
        const baseColor = CABLE_COLORS[simIndex % CABLE_COLORS.length]
        const color = connected ? baseColor : colors.dim

        // determine character based on curve direction
        const tPrev = Math.max(0, (i - 1) / steps)
        const tNext = Math.min(1, (i + 1) / steps)

        const prevX = Math.round(
          (1 - tPrev) * (1 - tPrev) * startX +
            2 * (1 - tPrev) * tPrev * ctrlX +
            tPrev * tPrev * endX
        )
        const prevY = Math.round(
          (1 - tPrev) * (1 - tPrev) * startY +
            2 * (1 - tPrev) * tPrev * ctrlY +
            tPrev * tPrev * endY
        )
        const nextX = Math.round(
          (1 - tNext) * (1 - tNext) * startX +
            2 * (1 - tNext) * tNext * ctrlX +
            tNext * tNext * endX
        )
        const nextY = Math.round(
          (1 - tNext) * (1 - tNext) * startY +
            2 * (1 - tNext) * tNext * ctrlY +
            tNext * tNext * endY
        )

        const dx = nextX - prevX
        const dy = nextY - prevY

        let char: string
        if (Math.abs(dx) > Math.abs(dy) * 2) {
          char = '─'
        } else if (Math.abs(dy) > Math.abs(dx) * 2) {
          char = '│'
        } else if ((dx > 0 && dy > 0) || (dx < 0 && dy < 0)) {
          char = '╲'
        } else {
          char = '╱'
        }

        return color(char)
      }
    }
  }

  return null
}

function truncate(str: string, maxLen: number): string {
  if (maxLen <= 0) return ''
  if (str.length <= maxLen) return str
  return str.slice(0, maxLen - 1) + '…'
}

function stripAnsi(str: string): string {
  return str.replace(/\x1b\[[0-9;]*m/g, '')
}

export function stopTUI(): void {
  if (refreshInterval) {
    clearInterval(refreshInterval)
    refreshInterval = null
  }
  if (physicsInterval) {
    clearInterval(physicsInterval)
    physicsInterval = null
  }
  if (stdinListener) {
    process.stdin.removeListener('data', stdinListener)
    stdinListener = null
  }
  if (resizeListener) {
    process.stdout.removeListener('resize', resizeListener)
    resizeListener = null
  }
  process.stdout.write(ansi.clearScreen + ansi.home + ansi.showCursor)

  if (process.stdin.isTTY) {
    process.stdin.setRawMode(false)
  }
  tuiState = null
  daemonState = null
}

// for pulse animations (called from server.ts)
export function triggerPulse(
  _serverId: string,
  _direction: 'request' | 'response'
): void {
  // TODO: implement pulse animations
}