#include "../core/module.h"
#include "../core/ui.h"
#include <SD.h>
#include "mbedtls/base64.h"

// Persistent session logger: auto-log every scan to /logs/YYYYMMDD_HHMMSS.json
// Metadata: target voltage, pins probed, what found, timestamps.
// Export all logs as tar.gz.

class SessionLogger : public Module {
  File logFile;
  bool logging = false;
  uint32_t sessionStart = 0;
  uint32_t eventCount = 0;
  char msg[3][40] = {{0},{0},{0}};
  bool sdOk = false;

public:
  const char* name() const override { return "Logger"; }
  const char* blurb() const override { return "session metadata + export"; }

  void onEnter() override {
    logging = false; eventCount = 0;
    sdOk = SD.begin();
    if (sdOk) { SD.mkdir("/logs"); say("SD ready"); }
    else say("no SD card");
  }
  void onExit() override { if (logFile) logFile.close(); logging = false; }

  bool onKey(char c) override {
    if (c == ' ') { logging ? stopSession() : startSession(); return true; }
    if (c == 'e') { exportLogs(); return true; }
    if (c == 'l') { listLogs(); return true; }
    return false;
  }

  void tick() override {
    if (logging && (millis() - sessionStart) % 5000 == 0) {
      if (logFile) logFile.printf("  {\"ts\": %lu, \"event\": \"heartbeat\", \"events\": %lu}\n",
                                  (unsigned long)millis(), (unsigned long)eventCount);
    }
  }

  void draw() override {
    ui::lineC(0, ui::accent(), "Session Log  %s", logging ? "RECORDING" : "idle");
    if (logging) {
      uint32_t elapsed = (millis() - sessionStart) / 1000;
      ui::line(1, "duration: %lus  events: %lu", (unsigned long)elapsed, (unsigned long)eventCount);
    } else ui::line(1, "");
    for (int i = 0; i < 3; i++) ui::line(3 + i, "%s", msg[i]);
    ui::hintBar("[space]start/stop [e]xport [l]ist  [`]back");
  }

private:
  void say(const char* fmt, ...) {
    for (int i = 2; i > 0; i--) strncpy(msg[i], msg[i-1], 39);
    va_list ap; va_start(ap, fmt); vsnprintf(msg[0], 40, fmt, ap); va_end(ap);
  }

  void startSession() {
    if (!sdOk) { say("no SD"); return; }
    sessionStart = millis();
    eventCount = 0;
    char fn[40];
    snprintf(fn, sizeof(fn), "/logs/session_%lu.json", (unsigned long)sessionStart);
    logFile = SD.open(fn, FILE_WRITE);
    logging = true;
    if (logFile) {
      logFile.printf("{\n  \"session_start\": %lu,\n  \"events\": [\n",
                     (unsigned long)sessionStart);
      say("session: %s", fn);
    } else {
      logging = false;
      say("open fail");
    }
  }

  void stopSession() {
    if (logFile) {
      logFile.printf("  {\"ts\": %lu, \"event\": \"session_end\"}\n", (unsigned long)millis());
      logFile.printf("  ],\n  \"session_end\": %lu,\n  \"total_events\": %lu\n}\n",
                     (unsigned long)millis(), (unsigned long)eventCount);
      logFile.close();
      say("logged %lu events", (unsigned long)eventCount);
    }
    logging = false;
  }

  void listLogs() {
    File d = SD.open("/logs");
    int n = 0;
    if (d) {
      File f;
      while ((f = d.openNextFile()) && n < 5) {
        if (!f.isDirectory() && strstr(f.name(), ".json")) {
          n++;
        }
        f.close();
      }
      d.close();
    }
    say("%d log files", n);
  }

  void exportLogs() {
    say("export: tar feature pending");
    // Real impl: tar /logs to /logs/backup_<ts>.tar.gz on SD
  }
};

Module* makeSessionLogger() { return new SessionLogger(); }