#include "UploadManager.h"
#include "Watchdog.h"

static const char* TAG_UPLOAD = "UPLOAD";
static const char* LOG_FILE = "/uploaded.csv";

UploadManager::UploadManager(APIClient& client, RTC_DS3231& rtc, DataCapture& capture) 
    : apiClient(client), rtc_(rtc), capture_(capture) {}

String UploadManager::getCurrentTimestamp() {
    DateTime now = rtc_.now();
    char buf[25];
    snprintf(buf, sizeof(buf), "%04u-%02u-%02u %02u:%02u:%02u",
             now.year(), now.month(), now.day(), now.hour(), now.minute(), now.second());
    return String(buf);
}

void UploadManager::appendLog(const String& filePath, const String& status) {
    File f = SD.open(LOG_FILE, FILE_APPEND);
    if (f) {
        f.printf("%s,%s,%s\n", getCurrentTimestamp().c_str(), filePath.c_str(), status.c_str());
        f.close();
    }
}

bool UploadManager::isAlreadyUploaded(const String& filePath) {
    File f = SD.open(LOG_FILE, FILE_READ);
    if (!f) return false;
    
    bool found = false;
    while (f.available()) {
        String line = f.readStringUntil('\n');
        line.trim();
        if (line.length() == 0) continue;
        
        int firstComma = line.indexOf(',');
        if (firstComma < 0) continue;
        int secondComma = line.indexOf(',', firstComma + 1);
        if (secondComma < 0) continue;
        
        String logPath = line.substring(firstComma + 1, secondComma);
        String logStatus = line.substring(secondComma + 1);
        
        if (logPath == filePath) {
            if (logStatus == "OK") found = true;
            else found = false; // A retry might be needed if last status wasn't OK
        }
        Watchdog::feed();
    }
    f.close();
    return found;
}

void UploadManager::uploadFile(const String& filePath) {
    if (isAlreadyUploaded(filePath)) {
        ESP_LOGI(TAG_UPLOAD, "File %s is already uploaded.", filePath.c_str());
        return;
    }
    
    if (WiFi.status() != WL_CONNECTED) {
        ESP_LOGE(TAG_UPLOAD, "No WiFi. Cannot upload %s", filePath.c_str());
        appendLog(filePath, "ERROR: No WiFi");
        return;
    }
    
    bool success = apiClient.uploadMeasurement(filePath);
    if (success) {
        appendLog(filePath, "OK");
    } else {
        if (WiFi.status() != WL_CONNECTED) {
            appendLog(filePath, "ERROR: WiFi lost during upload");
        } else {
            appendLog(filePath, "ERROR: Upload Failed");
        }
    }
}

void UploadManager::processPendingUploads() {
    if (WiFi.status() != WL_CONNECTED) return;
    
    ESP_LOGI(TAG_UPLOAD, "Checking for pending uploads...");
    uint32_t highestDir = capture_.findHighestNumericDir();
    if (highestDir == 0) return;
    
    for (uint32_t d = 1; d <= highestDir; d++) {
        String path = capture_.dirPath(d);
        File dir = SD.open(path);
        if (!dir || !dir.isDirectory()) {
            if(dir) dir.close();
            continue;
        }
        
        for (File f = dir.openNextFile(); f; f = dir.openNextFile()) {
            if (f.isDirectory()) { f.close(); continue; }
            String childPath = String(f.name()); 
            if (!childPath.startsWith("/")) {
                childPath = path + "/" + childPath;
            }
            
            if (childPath.endsWith(".wmt")) {
                if (!isAlreadyUploaded(childPath)) {
                    ESP_LOGI(TAG_UPLOAD, "Found pending file: %s", childPath.c_str());
                    uploadFile(childPath);
                    delay(1000); 
                }
            }
            f.close();
            Watchdog::feed();
            if (WiFi.status() != WL_CONNECTED) {
                dir.close();
                return; 
            }
        }
        dir.close();
    }
    ESP_LOGI(TAG_UPLOAD, "Pending uploads check complete.");
}