import QtQuick
import Quickshell
import Quickshell.Io
import "Model.js" as Model

// Service owns every conversation with streamdeck-ctl. The panel binds to the
// properties here and calls the functions; it never spawns a process itself.
Item {
  id: root

  property var settings: ({})

  // Set by the panel. While the popout is closed only the bar icon consumes
  // status, so polling relaxes to at most once a minute.
  property bool panelOpen: false

  // Full snapshot from `streamdeck-ctl status`, normalised by Model.parseStatus.
  property var status: Model.EMPTY_STATUS
  property bool loaded: false
  property bool refreshing: false
  property string lastError: ""
  property string actionStatus: ""

  // True once we have looked for the binary and failed — the panel shows install
  // guidance instead of controls in that state.
  property bool ctlMissing: false
  property string ctlResolved: ""

  readonly property bool busy: statusProcess.running || actionProcess.running
  readonly property bool connected: status.device.connected === true
  readonly property bool daemonActive: status.daemon.active === true

  // Brightness is echoed optimistically so the slider tracks the drag instead of
  // snapping back on the next poll, which lands up to refreshIntervalSec later.
  property int pendingBrightness: -1
  readonly property int brightness: pendingBrightness >= 0 ? pendingBrightness : (Number(status.brightness) || 0)

  readonly property int refreshIntervalSec: intSetting("refreshIntervalSec", 10, 2, 600)
  readonly property string configPath: String(setting("configPath", "") || "")

  function setting(name, fallback) {
    var value = settings ? settings[name] : undefined
    return value === undefined || value === null || value === "" ? fallback : value
  }

  function intSetting(name, fallback, min, max) {
    var n = parseInt(String(setting(name, fallback)), 10)
    if (!isFinite(n)) n = fallback
    return Math.max(min, Math.min(max, n))
  }

  // ── locating streamdeck-ctl ────────────────────────────────────────────────
  //
  // The shell inherits a minimal PATH under systemd, so ~/.local/bin (Linux) and
  // ~/go/bin (macOS, and Go's default install target) are checked explicitly
  // before falling back to a PATH lookup.
  readonly property string home: Quickshell.env("HOME")
  readonly property var candidatePaths: [
    String(setting("ctlPath", "") || ""),
    home + "/.local/bin/streamdeck-ctl",
    home + "/go/bin/streamdeck-ctl",
    "/usr/local/bin/streamdeck-ctl"
  ]

  function resolveCtl() {
    if (locateProcess.running) return
    locateProcess.command = ["sh", "-c", locateScript()]
    locateProcess.running = true
  }

  // A changed ctlPath setting (or HOME, in theory) must invalidate the cached
  // location — without this, ctlResolved is sticky for the life of the shell.
  onCandidatePathsChanged: {
    ctlResolved = ""
    ctlMissing = false
    resolveCtl()
  }

  function locateScript() {
    var checks = []
    for (var i = 0; i < candidatePaths.length; i++) {
      var path = candidatePaths[i]
      if (!path) continue
      checks.push('[ -x ' + shellQuote(path) + ' ] && { printf %s ' + shellQuote(path) + '; exit 0; }')
    }
    checks.push('command -v streamdeck-ctl 2>/dev/null || true')
    return checks.join("\n")
  }

  function shellQuote(value) {
    return "'" + String(value).replace(/'/g, "'\\''") + "'"
  }

  // baseArgs prefixes every invocation, carrying the -config override when the
  // widget was pointed at a non-default config.
  function baseArgs() {
    var args = []
    if (configPath !== "") args.push("-config", configPath)
    return args
  }

  // ── reading ────────────────────────────────────────────────────────────────

  function refresh() {
    if (ctlResolved === "") {
      if (!locateProcess.running) resolveCtl()
      return
    }
    if (statusProcess.running) return
    refreshing = true
    statusProcess.command = [ctlResolved].concat(baseArgs()).concat(["status"])
    statusProcess.running = true
  }

  // ── writing ────────────────────────────────────────────────────────────────

  function setBrightness(value) {
    var clamped = Math.max(0, Math.min(100, Math.round(value)))
    pendingBrightness = clamped
    brightnessDebounce.restart()
  }

  function toggleDaemon() {
    runAction(["daemon", "toggle"], daemonActive ? "Stopping daemon…" : "Starting daemon…")
  }

  function restartDaemon() {
    runAction(["daemon", "restart"], "Restarting daemon…")
  }

  function pressKey(index) {
    runAction(["key", "press", String(index)], "")
  }

  function clearKey(index) {
    runAction(["key", "clear", String(index)], "Cleared key " + index)
  }

  // saveKey takes the flag list Model.editArguments built. Returning early on an
  // empty list keeps a no-op "Save" from rewriting the config file.
  function saveKey(index, flags) {
    if (!flags || flags.length === 0) {
      actionStatus = "No changes"
      actionStatusTimer.restart()
      return
    }
    runAction(["key", "set", String(index)].concat(flags), "Saved key " + index)
  }

  // Writes are queued, not dropped: a save clicked while another action is in
  // flight must still land. Brightness entries coalesce to the newest value so
  // a slider drag queues one write, not a backlog of intermediate positions.
  property var actionQueue: []

  function runAction(args, message) {
    if (ctlResolved === "") { lastError = "streamdeck-ctl not found"; return }
    if (args[0] === "brightness") {
      actionQueue = actionQueue.filter(function(entry) { return entry.args[0] !== "brightness" })
    }
    actionQueue.push({ args: args, message: message })
    pumpActions()
  }

  function pumpActions() {
    if (actionProcess.running || actionQueue.length === 0) return
    var next = actionQueue.shift()
    actionProcess.pendingMessage = next.message
    actionProcess.command = [ctlResolved].concat(baseArgs()).concat(next.args)
    actionProcess.running = true
  }

  function openConfig() {
    var path = status.configPath || (home + "/.config/streamdeck-go/config.yaml")
    Quickshell.execDetached(["uwsm-app", "--", "xdg-open", path])
  }

  function openLogs() {
    Quickshell.execDetached(["uwsm-app", "--", "omarchy-launch-floating-terminal-with-presentation",
                             "journalctl", "--user", "-u", "streamdeck-go.service", "-f", "-n", "200"])
  }

  function openIcons() {
    var dir = status.iconsDir || (home + "/.config/streamdeck-go/icons")
    Quickshell.execDetached(["uwsm-app", "--", "xdg-open", dir])
  }

  // ── processes ──────────────────────────────────────────────────────────────

  Process {
    id: locateProcess
    running: false
    command: []
    stdout: StdioCollector { id: locateStdout; waitForEnd: true }
    onExited: function(exitCode) {
      var found = String(locateStdout.text || "").trim().split("\n")[0].trim()
      if (found !== "") {
        root.ctlResolved = found
        root.ctlMissing = false
        root.refresh()
      } else {
        root.ctlMissing = true
        root.loaded = true
      }
    }
  }

  Process {
    id: statusProcess
    running: false
    command: []
    stdout: StdioCollector { id: statusStdout; waitForEnd: true }
    stderr: StdioCollector { id: statusStderr; waitForEnd: true }
    onExited: function(exitCode) {
      root.refreshing = false
      root.loaded = true
      // A failure with empty stdout is spawn-shaped (the CLI always emits JSON,
      // even on error) — the binary may have been moved or removed. Drop the
      // cached location so the next tick re-probes.
      if (exitCode !== 0 && String(statusStdout.text || "").trim() === "") {
        root.ctlResolved = ""
        root.lastError = "streamdeck-ctl failed to run"
        return
      }
      var parsed = Model.parseStatus(statusStdout.text)
      if (parsed.ok === false && parsed.error) {
        root.lastError = parsed.error
        return
      }
      root.status = parsed
      root.lastError = parsed.configError ? parsed.configError
                     : (exitCode !== 0 ? String(statusStderr.text || "").trim() : "")
      // The poll caught up with the optimistic value — stop overriding it.
      if (root.pendingBrightness >= 0 && Number(parsed.brightness) === root.pendingBrightness) {
        root.pendingBrightness = -1
      }
    }
  }

  Process {
    id: actionProcess
    property string pendingMessage: ""
    running: false
    command: []
    stdout: StdioCollector { id: actionStdout; waitForEnd: true }
    stderr: StdioCollector { id: actionStderr; waitForEnd: true }
    onExited: function(exitCode) {
      if (exitCode === 0) {
        root.lastError = ""
        if (actionProcess.pendingMessage !== "") {
          root.actionStatus = actionProcess.pendingMessage
          actionStatusTimer.restart()
        }
      } else {
        var message = String(actionStderr.text || actionStdout.text || "").trim()
        root.lastError = Model.truncate(message || "streamdeck-ctl failed", 160)
        root.actionStatus = ""
        // A failed brightness write must release the optimistic value, or the
        // slider shows a level the deck never reached — forever, since no poll
        // will ever confirm it.
        root.pendingBrightness = -1
      }
      root.pumpActions()
      // Daemon transitions take a moment to settle; re-poll shortly after rather
      // than waiting for the next scheduled refresh.
      settleTimer.restart()
      root.refresh()
    }
  }

  // ── timers ─────────────────────────────────────────────────────────────────

  Timer {
    id: refreshTimer
    // The bar icon doesn't need panel-grade freshness; the panel refreshes
    // explicitly on open, so a slow background cadence costs nothing visible.
    interval: (root.panelOpen ? root.refreshIntervalSec
                              : Math.max(root.refreshIntervalSec, 60)) * 1000
    repeat: true
    running: true
    triggeredOnStart: true
    onTriggered: root.refresh()
  }

  Timer {
    // Dragging the slider would otherwise rewrite config.yaml on every pixel,
    // and each write triggers a daemon reload. Coalesce to the last value.
    id: brightnessDebounce
    interval: 180
    repeat: false
    onTriggered: {
      if (root.pendingBrightness < 0) return
      root.runAction(["brightness", String(root.pendingBrightness)], "")
    }
  }

  Timer {
    id: settleTimer
    interval: 1200
    repeat: false
    onTriggered: root.refresh()
  }

  Timer {
    id: actionStatusTimer
    interval: 2400
    repeat: false
    onTriggered: root.actionStatus = ""
  }

  Component.onCompleted: resolveCtl()
}