// VoiceNotes - voice recorder + AI notes for the Waveshare ESP32-C6-LCD-0.85
//
//   PLUS  click       -> start recording        (Button 1)
//   BOOT  click       -> stop & save to microSD  (Button 2)
//   PLUS  long-press  -> transcribe the latest recording, summarize it with
//                        Claude, and save both to microSD  (Button 3)
//
// Recordings: /recordings/REC_YYYY-MM-DD_HH-MM-SS.wav  (16 kHz mono WAV)
// Notes:      /notes/REC_..._transcript.txt  and  /notes/REC_..._summary.md

#include <OneButton.h>
#include <fcntl.h>
#include <unistd.h>
#include <SD.h>
#include <SPI.h>
#include <WiFi.h>
#include "app_state.h"
#include "audio.h"
#include "cloud.h"
#include "config.h"
#include "secrets.h"
#include "ui.h"

AppStatus app;
SemaphoreHandle_t spiMutex;

static OneButton btnPlus(PIN_BTN_PLUS, true, true);
static OneButton btnBoot(PIN_BTN_BOOT, true, true);
#if PIN_BTN_EXTRA >= 0
static OneButton btnExtra(PIN_BTN_EXTRA, true, true);
#endif

void setState(AppState s, const char *detail) {
  if (detail) strlcpy(app.detail, detail, sizeof(app.detail));
  app.stateSince = millis();
  app.state = s;
  static const char *names[] = {"BOOT", "NO_SD", "IDLE", "RECORDING", "SAVED", "UPLOADING",
                                "TRANSCRIBING", "SUMMARIZING", "SYNCING", "DONE", "ERROR"};
  Serial.printf("[state] %s %s\n", names[s], detail ? detail : "");
}

bool timeIsValid() { return time(nullptr) > 1700000000; }  // NTP has synced

// ---------------------------------------------------------------------------
static bool mountSD() {
  SpiLock lock;
  if (!SD.begin(PIN_SD_CS, SPI, SD_SPI_HZ) || SD.cardType() == CARD_NONE) {
    SD.end();
    return false;
  }
  SD.mkdir(DIR_RECORDINGS);
  SD.mkdir(DIR_NOTES);
  File f = SD.open(LAST_REC_FILE, FILE_READ);
  if (f) {
    String p = f.readStringUntil('\n');
    p.trim();
    f.close();
    if (SD.exists(p)) strlcpy(app.lastRecording, p.c_str(), sizeof(app.lastRecording));
  }
  Serial.printf("SD mounted, %llu MB free\n", (SD.totalBytes() - SD.usedBytes()) / 1048576);
  return true;
}

static bool canStartSomething() {
  AppState s = app.state;
  return s == ST_IDLE || s == ST_SAVED || s == ST_DONE || s == ST_ERROR;
}

// Button 1
static void startRecording() {
  if (!canStartSomething()) return;
  char path[64];
  if (timeIsValid()) {
    time_t now = time(nullptr);
    strftime(path, sizeof(path), DIR_RECORDINGS "/REC_%Y-%m-%d_%H-%M-%S.wav", localtime(&now));
  } else {
    // No network time yet (the C6 has no battery-backed clock).
    snprintf(path, sizeof(path), DIR_RECORDINGS "/REC_nodate_%08lx.wav", (unsigned long)esp_random());
  }
  // Limit the length to what fits on the card, keeping 50 MB spare.
  uint64_t freeBytes;
  {
    SpiLock lock;
    freeBytes = SD.totalBytes() - SD.usedBytes();
  }
  uint64_t fitSeconds = freeBytes > 50ULL * 1048576 ? (freeBytes - 50ULL * 1048576) / (SAMPLE_RATE * 2) : 0;
  if (fitSeconds < 60) {
    setState(ST_ERROR, "microSD card is full");
    return;
  }
  app.maxSeconds = (uint32_t)min((uint64_t)MAX_RECORD_SECONDS, fitSeconds);
  if (!recorderStart(path)) {
    setState(ST_ERROR, "Can't create file on microSD");
    return;
  }
  strlcpy(app.lastRecording, path, sizeof(app.lastRecording));
  setState(ST_RECORDING, path);
}

// Button 2
static void stopRecording() {
  if (app.state != ST_RECORDING) return;
  recorderStop();
  {
    SpiLock lock;
    File f = SD.open(LAST_REC_FILE, FILE_WRITE);
    if (f) {
      f.println(app.lastRecording);
      f.close();
    }
  }
  if (app.droppedBytes)
    Serial.printf("Warning: %lu bytes of audio dropped (slow SD card?)\n", app.droppedBytes);
  setState(ST_SAVED, strrchr(app.lastRecording, '/') + 1);
}

// Button 3
static void processLatest() {
  if (!canStartSomething()) return;
  if (!app.lastRecording[0]) {
    setState(ST_ERROR, "No recording yet - press PLUS to record");
    return;
  }
  if (WiFi.status() != WL_CONNECTED) {
    setState(ST_ERROR, "Wi-Fi not connected - check secrets.h");
    return;
  }
  if (!cloudStart(app.lastRecording)) setState(ST_ERROR, "Couldn't start network task");
}

// Runs on every (re)connect, after DHCP, so the DNS override survives lease renewals.
static void onGotIp(arduino_event_id_t, arduino_event_info_t) {
  Serial.printf("[wifi] IP %s, DHCP DNS %s / %s\n", WiFi.localIP().toString().c_str(),
                WiFi.dnsIP(0).toString().c_str(), WiFi.dnsIP(1).toString().c_str());
  IPAddress d1, d2;
  if (d1.fromString(DNS_PRIMARY)) {
    if (!d2.fromString(DNS_SECONDARY)) d2 = IPAddress();
    WiFi.setDNS(d1, d2);
    Serial.printf("[wifi] using DNS %s / %s\n", WiFi.dnsIP(0).toString().c_str(), WiFi.dnsIP(1).toString().c_str());
  }
}

// ---------------------------------------------------------------------------
void setup() {
  Serial.begin(115200);
  spiMutex = xSemaphoreCreateMutex();
  SPI.begin(PIN_SPI_SCK, PIN_SPI_MISO, PIN_SPI_MOSI);  // shared by LCD and microSD

  if (!uiBegin()) Serial.println("LCD init failed");
  setState(ST_BOOT);
  uiUpdate();

  WiFi.onEvent(onGotIp, ARDUINO_EVENT_WIFI_STA_GOT_IP);
  WiFi.mode(WIFI_STA);
  WiFi.setAutoReconnect(true);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  configTzTime(TIMEZONE, "pool.ntp.org", "time.google.com");

  btnPlus.attachClick(startRecording);
  btnPlus.setPressMs(BTN3_LONG_PRESS_MS);
  btnPlus.attachLongPressStart(processLatest);
  btnBoot.attachClick(stopRecording);
#if PIN_BTN_EXTRA >= 0
  btnExtra.attachClick(processLatest);
#endif

  bool micOk = audioBegin();
  bool sdOk = mountSD();

  // Give Wi-Fi + NTP up to 10 s so the first recording gets a real timestamp.
  uint32_t t0 = millis();
  while (millis() - t0 < 10000 && !timeIsValid()) {
    uiUpdate();
    delay(10);
  }
  Serial.printf("Wi-Fi %s, clock %s\n", WiFi.status() == WL_CONNECTED ? "connected" : "offline",
                timeIsValid() ? "synced" : "not set");

  if (!micOk) setState(ST_ERROR, "Microphone init failed");
  else if (!sdOk) setState(ST_NO_SD);
  else setState(ST_IDLE);
}

// Serial commands (115200 baud), handy for testing without the buttons:
//   p = transcribe + summarize the latest recording (same as holding PLUS)
//   s = read the latest recording back from the SD card and report the result
//   d = list /recordings
//   w = show Wi-Fi and DNS status
//   r / x = start / stop recording (same as PLUS / BOOT)
//   a = measure each microphone's level for 2 s
//   n = print the notes (transcript + summary) for the latest recording
//   u<file name> = choose which recording p and n use, e.g. uREC_2026-10-03_15-31-12.wav
static void sdReadTest() {
  if (!app.lastRecording[0]) { Serial.println("[test] no recording yet"); return; }
  SpiLock lock;
  uint32_t t0 = millis();
  int fd = open((String("/sd") + app.lastRecording).c_str(), O_RDONLY);
  if (fd < 0) { Serial.printf("[test] open %s failed (errno %d)\n", app.lastRecording, errno); return; }
  static uint8_t buf[512];  // single-sector reads, see sdRead() in cloud.cpp
  size_t total = 0;
  int n;
  while ((n = read(fd, buf, sizeof(buf))) > 0) total += n;
  int e = n < 0 ? errno : 0;
  close(fd);
  Serial.printf("[test] read %u bytes of %s in %lu ms (errno %d %s)\n", (unsigned)total, app.lastRecording,
                millis() - t0, e, strerror(e));
}

static void sdList() {
  SpiLock lock;
  File dir = SD.open(DIR_RECORDINGS);
  for (File f = dir.openNextFile(); f; f = dir.openNextFile())
    Serial.printf("[test]   %-40s %8u bytes\n", f.name(), (unsigned)f.size());
  dir.close();
}

static void printFile(const String &path) {
  SpiLock lock;
  int fd = open((String("/sd") + path).c_str(), O_RDONLY);
  if (fd < 0) { Serial.printf("[test] %s not found\n", path.c_str()); return; }
  Serial.printf("===== %s =====\n", path.c_str());
  static uint8_t buf[512];
  int n;
  while ((n = read(fd, buf, sizeof(buf))) > 0) Serial.write(buf, n);
  close(fd);
  Serial.println("\n===== end =====");
}

static void printNotes() {
  if (!app.lastRecording[0]) { Serial.println("[test] no recording yet"); return; }
  String base = String(strrchr(app.lastRecording, '/') + 1);
  base.replace(".wav", "");
  printFile(String(DIR_NOTES "/") + base + "_transcript.txt");
  printFile(String(DIR_NOTES "/") + base + "_summary.md");
}

static void serialCommands() {
  while (Serial.available()) {
    switch (Serial.read()) {
      case 'p': Serial.println("[test] start pipeline"); processLatest(); break;
      case 's': sdReadTest(); break;
      case 'd': sdList(); break;
      case 'n': printNotes(); break;
      case 'r': startRecording(); break;
      case 'a': audioLevelReport(2000); break;
      case 'x': stopRecording(); break;
      case 'w':
        Serial.printf("[wifi] %s, IP %s, DNS %s / %s, RSSI %d dBm\n", WiFi.isConnected() ? "connected" : "offline",
                      WiFi.localIP().toString().c_str(), WiFi.dnsIP(0).toString().c_str(),
                      WiFi.dnsIP(1).toString().c_str(), WiFi.RSSI());
        break;
      case 'u': {
        String name = Serial.readStringUntil('\n');
        name.trim();
        String path = String(DIR_RECORDINGS "/") + name;
        bool found;
        {
          SpiLock lock;
          found = SD.exists(path);
        }
        if (found) strlcpy(app.lastRecording, path.c_str(), sizeof(app.lastRecording));
        Serial.printf("[test] %s %s\n", found ? "using" : "not found:", path.c_str());
        break;
      }
    }
  }
}

void loop() {
  serialCommands();
  btnPlus.tick();
  btnBoot.tick();
#if PIN_BTN_EXTRA >= 0
  btnExtra.tick();
#endif

  recorderService();
  if (app.state == ST_RECORDING && recorderSeconds() >= app.maxSeconds) {
    Serial.println("Max length reached, stopping");
    stopRecording();
  }

  // Result screens fall back to the ready screen after a while.
  uint32_t inState = millis() - app.stateSince;
  if ((app.state == ST_SAVED && inState > 5000) ||
      ((app.state == ST_DONE || app.state == ST_ERROR) && inState > 15000)) {
    setState(ST_IDLE);
  }

  static uint32_t lastSdTry = 0;
  if (app.state == ST_NO_SD && millis() - lastSdTry > 3000) {
    lastSdTry = millis();
    if (mountSD()) setState(ST_IDLE);
  }

  uiUpdate();
  delay(2);
}