package recreationaltech.plugin

import groovy.util.logging.Slf4j

import java.nio.file.Files
import java.nio.file.Path

/**
 * Provides runtime estimates for tasks based on task-name and input file size
 */
@Slf4j
abstract class K8sRuntimeEstimator {
    /**
     * Returns an estimation of the task runtime in milliseconds
     * @param handler the task handler
     * @return estimated task runtime in milliseconds OR infinity if the task is unknown.
     */
    double estimate(K8sTaskHandler handler) {
        long x = getTaskHandlerInputSize(handler)
        return estimate(handler.task.processor.name, x)
    }

    /**
     * Returns an estimation of the task runtime in milliseconds
     * @param taskName the name of the task
     * @param inputSize the total input size in bytes
     * @return estimated task runtime in milliseconds OR infinity if the task is unknown.
     */
    abstract double estimate(String taskName, long inputSize);

    protected long getTaskHandlerInputSize(K8sTaskHandler handler) {
        long inputSizeSum = 0
        // File input
        def inputFiles = handler.task.getInputFilesMap()
        for (Map.Entry<String, Path> f : inputFiles) {
            try {
                inputSizeSum += Files.size(f.value)
            } catch (IOException ex) {
                log.error "[K8s] failed to get size of input file ${f.value} of task ${task.task.name}: ${ex.message}"
            }
        }
        // Non file input
        def inputs = handler.task.getInputs()
        for (Map.Entry i : inputs) {
            inputSizeSum += i.value.toString().length()
        }

        return inputSizeSum
    }

    /// @brief Parses the runtime recording data file
    /// @return Map from task name to list of recordings, where each recording is a tuple (input-size, runtime-in-ms)
    protected HashMap<String, ArrayList<Tuple2<Long, Long>>> parseDataFile(String dataFilePath) {
        HashMap<String, ArrayList<Tuple2<Long, Long>>> data = new HashMap<>();
        try {
            BufferedReader reader = new BufferedReader(new FileReader(dataFilePath))
            String line = reader.readLine()
            while (line != null) {
                // <task-name>,<input-size>,<runtime-ms>
                String[] elems = line.split(",")
                if (elems.length != 3) {
                    log.warn "[K8s] ${dataFilePath}: Unexpected line ${line}"
                    continue
                }

                ArrayList<Tuple2<Long, Long>> taskData = data.get(elems[0])
                if (taskData == null) {
                    taskData = new ArrayList<>()
                    data.put(elems[0], taskData)
                }
                try {
                    taskData.add(new Tuple2(Long.parseLong(elems[1]), Long.parseLong(elems[2])))
                } catch (NumberFormatException ex) {
                    log.error "[K8s] ${dataFilePath} invalid data: ${ex.message}"
                }
                line = reader.readLine()
            }
            reader.close()
        } catch (IOException ex) {
            log.error "[K8s] Failed to load ${dataFilePath}: ${ex.message}"
        }
        return data
    }
}