import 'package:tasq/models/leave_of_absence.model.dart';
import 'package:tasq/models/pass_slip.model.dart';
import 'package:tasq/models/profile.model.dart';
import 'package:tasq/models/programmer_task.model.dart';
import 'package:tasq/models/programmer_task_work_log.model.dart';
import 'package:tasq/providers/programmer_day_data_provider.dart';
import 'package:tasq/utils/programmer_day_rows.dart';

enum MonitorState { working, paused, idle, onLeave, passSlip }

class HelpEdge {
  final String helperId;
  final String assigneeId;
  final String taskId;
  final String taskTitle;
  final int minutes;
  final DateTime at;

  HelpEdge({
    required this.helperId,
    required this.assigneeId,
    required this.taskId,
    required this.taskTitle,
    required this.minutes,
    required this.at,
  });
}

/// Build help edges from work logs for a given day.
///
/// Returns edges where:
/// - author != assignee (author is helping)
/// - minutes > 0
/// - workDate == day
///
/// Sorted by createdAt newest first.
List<HelpEdge> buildHelpEdges({
  required List<ProgrammerTaskWorkLog> workLogs,
  required Map<String, ProgrammerTask> taskById,
  required DateTime day,
}) {
  final edges = <HelpEdge>[];

  for (final log in workLogs) {
    final task = taskById[log.taskId];
    if (task == null) continue;

    // Filter: author != assignee AND minutes > 0 AND workDate == day
    if (log.authorId == task.assigneeId) continue;
    if (log.minutes == null || log.minutes! <= 0) continue;
    if (log.workDate != day) continue;

    edges.add(HelpEdge(
      helperId: log.authorId,
      assigneeId: task.assigneeId ?? '',
      taskId: log.taskId,
      taskTitle: task.title,
      minutes: log.minutes!,
      at: log.createdAt,
    ));
  }

  // Sort by createdAt newest first
  edges.sort((a, b) => b.at.compareTo(a.at));

  return edges;
}

class ProgrammerMonitorEntry {
  final Profile programmer;
  final MonitorState state;
  final ProgrammerTask? currentTask;
  final Duration currentTaskToday;
  final Duration todayTotal;
  final int inProgress;
  final int paused;
  final int notStarted;
  final String? sheetStatus;
  final List<HelpEdge> helped;
  final List<HelpEdge> helpedBy;

  ProgrammerMonitorEntry({
    required this.programmer,
    required this.state,
    required this.currentTask,
    required this.currentTaskToday,
    required this.todayTotal,
    required this.inProgress,
    required this.paused,
    required this.notStarted,
    this.sheetStatus,
    required this.helped,
    required this.helpedBy,
  });
}

/// Build monitor entries for all programmers for a given day.
///
/// Sort order: working -> paused -> idle -> passSlip -> onLeave,
/// then alphabetical by programmer.fullName within each state group.
///
/// Parameters [leaves] and [passSlips] should be pre-computed maps from
/// activeLeaveByUser() and activePassSlipByUser() respectively.
List<ProgrammerMonitorEntry> buildMonitorEntries({
  required List<Profile> programmers,
  required DayActivityData today,
  required Map<String, ProgrammerRunInfo> runStates,
  required Map<String, LeaveOfAbsence> leaves,
  required Map<String, PassSlip> passSlips,
  required Map<String, String> sheetStatusByUser,
  required Map<String, String> projectNames,
  required Map<String, String> profileNames,
  required DateTime now,
}) {
  final taskById = {for (final t in today.tasks) t.id: t};

  final entries = <ProgrammerMonitorEntry>[];

  for (final programmer in programmers) {
    final programmerId = programmer.id;

    // Step 1: Determine state
    // Priority: onLeave > passSlip > working/paused/idle
    MonitorState state;
    if (leaves.containsKey(programmerId)) {
      state = MonitorState.onLeave;
    } else if (passSlips.containsKey(programmerId)) {
      state = MonitorState.passSlip;
    } else {
      // Determine from task states
      state = _determineState(programmerId, today.tasks, runStates);
    }

    // Step 2: Find current task (oldest running task)
    ProgrammerTask? currentTask;
    if (state == MonitorState.working) {
      currentTask = _findCurrentTask(programmerId, today.tasks, runStates);
    }

    // Step 3: Count tasks by state
    final (inProgress, paused, notStarted) =
        _countTasksByState(programmerId, today.tasks, runStates);

    // Step 4: Calculate durations
    final allTasksRows = buildDayRows(
      userId: programmerId,
      day: today.day,
      tasks: today.tasks,
      logsByTask: today.logsByTask,
      workLogs: today.workLogs,
      projectNames: projectNames,
      profileNames: profileNames,
      now: now,
    );
    final todayTotal = Duration(seconds: totalSeconds(allTasksRows));

    // For current task, filter to only that task's work logs
    final currentTaskToday = _calculateCurrentTaskDuration(
      programmerId,
      currentTask,
      today,
      projectNames,
      profileNames,
      now,
    );

    // Step 5: Build helped and helpedBy edges
    final helped = _buildHelpedEdges(programmerId, today.workLogs, taskById, today.day);
    final helpedBy = _buildHelpedByEdges(programmerId, today.workLogs, taskById, today.day);

    entries.add(ProgrammerMonitorEntry(
      programmer: programmer,
      state: state,
      currentTask: currentTask,
      currentTaskToday: currentTaskToday,
      todayTotal: todayTotal,
      inProgress: inProgress,
      paused: paused,
      notStarted: notStarted,
      sheetStatus: sheetStatusByUser[programmerId],
      helped: helped,
      helpedBy: helpedBy,
    ));
  }

  // Sort by state then by name
  entries.sort((a, b) {
    final stateOrder = [
      MonitorState.working,
      MonitorState.paused,
      MonitorState.idle,
      MonitorState.passSlip,
      MonitorState.onLeave,
    ];
    final aStateIdx = stateOrder.indexOf(a.state);
    final bStateIdx = stateOrder.indexOf(b.state);

    if (aStateIdx != bStateIdx) {
      return aStateIdx.compareTo(bStateIdx);
    }

    return a.programmer.fullName.compareTo(b.programmer.fullName);
  });

  return entries;
}

/// Determine state from task states
MonitorState _determineState(
  String programmerId,
  List<ProgrammerTask> tasks,
  Map<String, ProgrammerRunInfo> runStates,
) {
  final programmerTasks = tasks.where((t) => t.assigneeId == programmerId).toList();

  var hasRunning = false;
  var hasPaused = false;

  for (final task in programmerTasks) {
    final runInfo = runStates[task.id];
    if (runInfo == null) continue;

    if (runInfo.state == ProgrammerRunState.running) {
      hasRunning = true;
    } else if (runInfo.state == ProgrammerRunState.paused) {
      hasPaused = true;
    }
  }

  if (hasRunning) return MonitorState.working;
  if (hasPaused) return MonitorState.paused;
  return MonitorState.idle;
}

/// Find the current task (oldest running task by since)
ProgrammerTask? _findCurrentTask(
  String programmerId,
  List<ProgrammerTask> tasks,
  Map<String, ProgrammerRunInfo> runStates,
) {
  final runningTasks = tasks
      .where((t) =>
          t.assigneeId == programmerId &&
          runStates[t.id]?.state == ProgrammerRunState.running)
      .toList();

  if (runningTasks.isEmpty) return null;

  // Sort by since (earliest first)
  runningTasks.sort((a, b) {
    final aSince = runStates[a.id]?.since ?? DateTime(0);
    final bSince = runStates[b.id]?.since ?? DateTime(0);
    return aSince.compareTo(bSince);
  });

  return runningTasks.first;
}

/// Count tasks by state
(int inProgress, int paused, int notStarted) _countTasksByState(
  String programmerId,
  List<ProgrammerTask> tasks,
  Map<String, ProgrammerRunInfo> runStates,
) {
  var inProgress = 0;
  var paused = 0;
  var notStarted = 0;

  final programmerTasks = tasks.where((t) => t.assigneeId == programmerId).toList();

  for (final task in programmerTasks) {
    final runInfo = runStates[task.id];
    if (runInfo == null) continue;

    if (runInfo.state == ProgrammerRunState.running ||
        runInfo.state == ProgrammerRunState.paused) {
      // This is still "in progress" (running or paused)
      // We count these separately
      if (runInfo.state == ProgrammerRunState.running) {
        inProgress++;
      } else {
        paused++;
      }
    } else if (runInfo.state == ProgrammerRunState.notStarted) {
      notStarted++;
    }
  }

  return (inProgress, paused, notStarted);
}

/// Calculate duration for current task
Duration _calculateCurrentTaskDuration(
  String programmerId,
  ProgrammerTask? currentTask,
  DayActivityData today,
  Map<String, String> projectNames,
  Map<String, String> profileNames,
  DateTime now,
) {
  if (currentTask == null) return Duration.zero;

  // Filter work logs to only this task
  final currentTaskLogs =
      today.workLogs.where((w) => w.taskId == currentTask.id).toList();

  // Filter activity logs to only this task
  final currentTaskActivityLogs = {
    currentTask.id: today.logsByTask[currentTask.id] ?? []
  };

  final rows = buildDayRows(
    userId: programmerId,
    day: today.day,
    tasks: [currentTask],
    logsByTask: currentTaskActivityLogs,
    workLogs: currentTaskLogs,
    projectNames: projectNames,
    profileNames: profileNames,
    now: now,
  );

  return Duration(seconds: totalSeconds(rows));
}

/// Build helped edges (where programmer helped others)
List<HelpEdge> _buildHelpedEdges(
  String programmerId,
  List<ProgrammerTaskWorkLog> workLogs,
  Map<String, ProgrammerTask> taskById,
  DateTime day,
) {
  final edges = <HelpEdge>[];

  for (final log in workLogs) {
    // Filter: author == programmer AND author != assignee AND minutes > 0 AND workDate == day
    if (log.authorId != programmerId) continue;

    final task = taskById[log.taskId];
    if (task == null) continue;

    if (log.authorId == task.assigneeId) continue;
    if (log.minutes == null || log.minutes! <= 0) continue;
    if (log.workDate != day) continue;

    edges.add(HelpEdge(
      helperId: log.authorId,
      assigneeId: task.assigneeId ?? '',
      taskId: log.taskId,
      taskTitle: task.title,
      minutes: log.minutes!,
      at: log.createdAt,
    ));
  }

  // Sort by createdAt newest first
  edges.sort((a, b) => b.at.compareTo(a.at));
  return edges;
}

/// Build helpedBy edges (where others helped programmer)
List<HelpEdge> _buildHelpedByEdges(
  String programmerId,
  List<ProgrammerTaskWorkLog> workLogs,
  Map<String, ProgrammerTask> taskById,
  DateTime day,
) {
  final edges = <HelpEdge>[];

  for (final log in workLogs) {
    final task = taskById[log.taskId];
    if (task == null) continue;

    // Filter: task assigned to programmer AND author != programmer AND minutes > 0 AND workDate == day
    if (task.assigneeId != programmerId) continue;

    if (log.authorId == programmerId) continue;
    if (log.minutes == null || log.minutes! <= 0) continue;
    if (log.workDate != day) continue;

    edges.add(HelpEdge(
      helperId: log.authorId,
      assigneeId: programmerId,
      taskId: log.taskId,
      taskTitle: task.title,
      minutes: log.minutes!,
      at: log.createdAt,
    ));
  }

  // Sort by createdAt newest first
  edges.sort((a, b) => b.at.compareTo(a.at));
  return edges;
}