/*
  ESP32 16-Sensor Logger - Chart Loading Fixed
*/

#include <WiFi.h>
#include <ESPAsyncWebServer.h>
#include <AsyncTCP.h>
#include <SD.h>
#include <SPI.h>
#include <time.h>
#include <Arduino_JSON.h>

#define SD_CS   5
#define SD_MOSI 23
#define SD_MISO 19
#define SD_SCK  18

const char* setupFile = "/setup.csv";
const int MAX_POINTS = 64;
const int NUM_SENSORS = 16;

AsyncWebServer server(80);

String sensorNames[NUM_SENSORS];
String ssidStr = "Wokwi-GUEST";
String passStr = "";
bool visible[NUM_SENSORS];

String getCurrentDateFile() {
  struct tm timeinfo;
  if (!getLocalTime(&timeinfo)) return "20260715.csv";
  char buf[20];
  sprintf(buf, "%04d%02d%02d.csv", timeinfo.tm_year + 1900, timeinfo.tm_mon + 1, timeinfo.tm_mday);
  return String(buf);
}

void setDefaultNames() {
  for (int i = 0; i < NUM_SENSORS; i++) {
    sensorNames[i] = "Sensor" + String(i + 1);
    visible[i] = true;
  }
}

void initSD() {
  SPI.begin(SD_SCK, SD_MISO, SD_MOSI, SD_CS);
  if (!SD.begin(SD_CS)) {
    Serial.println("SD Card failed!");
    return;
  }
  Serial.println("SD Card initialized.");

  if (!SD.exists(setupFile)) saveSetup();
  else loadSetup();
}

void loadSetup() {
  File f = SD.open(setupFile, FILE_READ);
  if (!f) return;
  String content = f.readString();
  f.close();

  JSONVar doc = JSON.parse(content);
  if (JSON.typeof(doc) == "undefined") return;

  ssidStr = (const char*)doc["ssid"];
  passStr = (const char*)doc["password"];

  JSONVar names = doc["names"];
  JSONVar vis = doc["visible"];
  for (int i = 0; i < NUM_SENSORS; i++) {
    if (i < names.length()) sensorNames[i] = (const char*)names[i];
    if (i < vis.length()) visible[i] = (bool)vis[i];
  }
}

void saveSetup() {
  JSONVar doc;
  doc["ssid"] = ssidStr;
  doc["password"] = passStr;
  JSONVar names, vis;
  for (int i = 0; i < NUM_SENSORS; i++) {
    names[i] = sensorNames[i];
    vis[i] = visible[i];
  }
  doc["names"] = names;
  doc["visible"] = vis;

  File f = SD.open(setupFile, FILE_WRITE);
  if (f) {
    f.print(JSON.stringify(doc));
    f.close();
  }
}

String getTimestamp() {
  struct tm timeinfo;
  if (!getLocalTime(&timeinfo)) return "1970-01-01 00:00:00";
  char buf[20];
  sprintf(buf, "%04d-%02d-%02d %02d:%02d:%02d", 
          timeinfo.tm_year + 1900, timeinfo.tm_mon + 1, timeinfo.tm_mday,
          timeinfo.tm_hour, timeinfo.tm_min, timeinfo.tm_sec);
  return String(buf);
}

void logData(float values[]) {
  String ts = getTimestamp();
  Serial.println("Logged: " + ts);
  String line = ts;
  for (int i = 0; i < NUM_SENSORS; i++) {
    line += "," + String(values[i], 2);
  }

  String todayFile = getCurrentDateFile();
  File file = SD.open(todayFile.c_str(), FILE_READ);
  String lines[MAX_POINTS + 2];
  int count = 0;
  if (file) {
    while (file.available() && count < MAX_POINTS + 1) {
      lines[count++] = file.readStringUntil('\n');
    }
    file.close();
  }

  if (count - 1 >= MAX_POINTS) {
    for (int i = 1; i < count - 1; i++) lines[i] = lines[i + 1];
    count--;
  }
  if (count == 0) {
    String header = "timestamp";
    for (int i = 0; i < NUM_SENSORS; i++) header += "," + sensorNames[i];
    lines[count++] = header;
  }
  lines[count++] = line;

  file = SD.open(todayFile.c_str(), FILE_WRITE);
  if (file) {
    for (int i = 0; i < count; i++) file.println(lines[i]);
    file.close();
  }
}

void setup() {
  Serial.begin(115200);
  setDefaultNames();
  initSD();

  WiFi.begin(ssidStr.c_str(), passStr.c_str());
  Serial.print("Connecting to WiFi");
  unsigned long start = millis();
  while (WiFi.status() != WL_CONNECTED && millis() - start < 20000) {
    delay(500);
    Serial.print(".");
  }
  Serial.println(WiFi.status() == WL_CONNECTED ? "\nConnected! IP: " + WiFi.localIP().toString() : "\nWiFi failed");

  configTime(-18000, 0, "pool.ntp.org");
  setenv("TZ", "CST6CDT,M3.2.0,M11.1.0", 1);
  tzset();

  // Main Page
  server.on("/", HTTP_GET, [](AsyncWebServerRequest *request) {
    String visArray = "[";
    for (int i = 0; i < NUM_SENSORS; i++) {
      visArray += visible[i] ? "true" : "false";
      if (i < NUM_SENSORS - 1) visArray += ",";
    }
    visArray += "]";

    String html = R"rawliteral(
<!DOCTYPE html>
<html>
<head>
  <title>ESP32 Logger</title>
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <script src="https://code.highcharts.com/highcharts.js"></script>
  <style>
    body {font-family:Arial,sans-serif;background:#f4f4f4;margin:0;padding:20px;}
    .container {max-width:1450px;margin:auto;background:white;padding:25px;border-radius:10px;box-shadow:0 4px 20px rgba(0,0,0,0.1);}
    .controls {display:flex;flex-wrap:wrap;gap:12px;justify-content:center;margin:15px 0;align-items:center;}
    .chart-container {height:580px;margin-top:20px;}
    .status {margin-top:25px;padding:12px;background:#e8f4fd;border-radius:6px;text-align:center;font-size:0.95em;}
  </style>
</head>
<body>
  <div class="container">
    <h1>ESP32 16-Sensor Logger</h1>
    <div class="controls">
      <button onclick="manualRefresh()">Refresh Now</button>
      <button onclick="window.location='/setup'">Setup</button>
      <button onclick="downloadCSV()">Download CSV</button>
      <label>Date: <input type="date" id="logDate" onchange="loadSelectedFile()"></label>
      <label>Start: <input type="time" id="startTime"></label>
      <label>End: <input type="time" id="endTime"></label>
    </div>
    <div id="chart-container" class="chart-container"></div>
    <div class="status" id="status">Loading...</div>
  </div>

  <script>
    let chart, allData = [], currentNames = [];
    const visibleSensors = )rawliteral" + visArray + R"rawliteral(;
    let currentFile = '';

    function getTodayDate() {
      const now = new Date();
      const y = now.getFullYear();
      const m = String(now.getMonth()+1).padStart(2,'0');
      const d = String(now.getDate()).padStart(2,'0');
      return `${y}-${m}-${d}`;
    }

    async function loadSelectedFile() {
      const dateInput = document.getElementById('logDate').value;
      if (!dateInput) return;
      currentFile = dateInput.replace(/-/g,'') + '.csv';
      try {
        const r = await fetch('/file?file=' + encodeURIComponent(currentFile));
        if (!r.ok) throw new Error('File not found');
        const csv = await r.text();
        parseCSV(csv);
        updateChart();
      } catch(e) { 
        console.error(e);
        document.getElementById('status').innerHTML += ' (File not found)';
      }
    }

    async function manualRefresh() {
      document.getElementById('logDate').value = getTodayDate();
      loadSelectedFile();
    }

    function parseCSV(csv) {
      const lines = csv.trim().split('\n');
      const headers = lines[0].split(',');
      currentNames = headers.slice(1);
      allData = [];
      for (let i=1; i<lines.length; i++) {
        const v = lines[i].split(',');
        if (v.length < 2) continue;
        let e = {timestamp: v[0]};
        for (let j=1; j<headers.length; j++) e[headers[j]] = parseFloat(v[j]) || 0;
        allData.push(e);
      }
    }

    function updateChart() {
      const filtered = allData.filter(p => {
        const s = document.getElementById('startTime').value;
        const e = document.getElementById('endTime').value;
        if (s && p.timestamp.split(' ')[1] < s) return false;
        if (e && p.timestamp.split(' ')[1] > e) return false;
        return true;
      });

      const series = [];
      currentNames.forEach((name, i) => {
        if (visibleSensors[i]) {
          series.push({
            name: name,
            data: filtered.map(p => [new Date(p.timestamp.replace(' ','T') + '-05:00').getTime(), p[name]])
          });
        }
      });

      if (chart) chart.destroy();
      chart = Highcharts.chart('chart-container', {
        title: {text: 'Sensor Data'},
        xAxis: {type: 'datetime'},
        yAxis: {title: {text: 'Value'}},
        series: series
      });
    }

    function updateStatus() {
      const now = new Date();
      document.getElementById('status').innerHTML = `
        <strong>Current Time:</strong> ${now.toLocaleString()} &nbsp;|&nbsp; 
        <strong>SSID:</strong> ${'SSID_PLACEHOLDER'} &nbsp;|&nbsp; 
        <strong>IP:</strong> ${'IP_PLACEHOLDER'} &nbsp;|&nbsp; 
        <strong>CSV:</strong> ${currentFile || 'today.csv'}
      `;
    }

    function downloadCSV() {
      if (currentFile) window.location = '/file?file=' + encodeURIComponent(currentFile);
    }

    window.onload = () => {
      document.getElementById('logDate').value = getTodayDate();
      manualRefresh();
      setInterval(() => {
        if (document.getElementById('logDate').value === getTodayDate()) manualRefresh();
      }, 30000);
      setInterval(updateStatus, 1000);
      updateStatus();
    };
  </script>
</body>
</html>
    )rawliteral";

    html.replace("SSID_PLACEHOLDER", ssidStr);
    html.replace("IP_PLACEHOLDER", WiFi.localIP().toString());
    request->send(200, "text/html", html);
  });

  server.on("/file", HTTP_GET, [](AsyncWebServerRequest *request) {
    if (request->hasParam("file")) {
      String file = request->getParam("file")->value();
      if (SD.exists(file.c_str())) {
        request->send(SD, file.c_str(), "text/csv");
        return;
      }
    }
    request->send(404, "text/plain", "File not found");
  });

  server.on("/setup", HTTP_GET, [](AsyncWebServerRequest *request) {
    String html = "<!DOCTYPE html><html><head><title>Setup</title></head><body>";
    html += "<h1>Configuration</h1><form action='/save' method='POST'>";
    html += "SSID: <input name='ssid' value='" + ssidStr + "'><br><br>";
    html += "Password: <input name='password' value='" + passStr + "'><br><br>";
    html += "<h2>Sensor Names & Visibility</h2>";
    for (int i = 0; i < NUM_SENSORS; i++) {
      String ch = visible[i] ? "checked" : "";
      html += "Sensor " + String(i+1) + ": <input name='name" + String(i) + "' value='" + sensorNames[i] + "'> ";
      html += "<input type='checkbox' name='vis" + String(i) + "' value='1' " + ch + "> Visible<br>";
    }
    html += "<br><button type='submit'>Save Settings</button></form>";
    html += "<br><a href='/'>← Back to Dashboard</a>";

    html += "<div style='margin-top:30px;padding:15px;background:#e8f4fd;border-radius:6px;text-align:center;'>";
    html += "<strong>Setup File:</strong> " + String(setupFile) + "<br>";
    html += "<strong>Current Time:</strong> <span id='setupTime'></span>";
    html += "</div>";

    html += R"rawliteral(
    <script>
      function updateSetupTime() {
        const now = new Date();
        document.getElementById('setupTime').innerText = now.toLocaleString();
      }
      setInterval(updateSetupTime, 1000);
      updateSetupTime();
    </script>
    </body></html>
    )rawliteral";
    request->send(200, "text/html", html);
  });

  server.on("/save", HTTP_POST, [](AsyncWebServerRequest *request) {
    if (request->hasParam("ssid", true)) ssidStr = request->getParam("ssid", true)->value();
    if (request->hasParam("password", true)) passStr = request->getParam("password", true)->value();

    for (int i = 0; i < NUM_SENSORS; i++) {
      String nKey = "name" + String(i);
      String vKey = "vis" + String(i);
      if (request->hasParam(nKey, true)) sensorNames[i] = request->getParam(nKey, true)->value();
      visible[i] = request->hasParam(vKey, true);
    }
    saveSetup();
    request->redirect("/");
  });

  server.begin();
  Serial.println("Web server started.");
}

void loop() {
  static unsigned long lastLog = 0;
  if (millis() - lastLog > 1000) {
    lastLog = millis();
    float values[16];
    for (int i = 0; i < NUM_SENSORS; i++) {
      values[i] = 20.0 + i * 0.5 + (random(-20, 21) / 10.0);
    }
    logData(values);
  }
}