import { db, logger } from '../config.js';
import { qsos } from '../db/schema/index.js';
import { eq, and, or, desc, sql } from 'drizzle-orm';
import { readFileSync, readdirSync } from 'fs';
import { join } from 'path';
import { getCachedAwardProgress, setCachedAwardProgress } from './cache.service.js';

/**
 * Awards Service
 * Calculates award progress based on QSO data
 */

// Load award definitions from files
const AWARD_DEFINITIONS_DIR = join(process.cwd(), 'award-definitions');

// In-memory cache for award definitions (static, never changes at runtime)
let cachedAwardDefinitions = null;

/**
 * Load all award definitions (cached in memory)
 */
function loadAwardDefinitions() {
  // Return cached definitions if available
  if (cachedAwardDefinitions) {
    return cachedAwardDefinitions;
  }

  const definitions = [];

  try {
    // Auto-discover all JSON files in the award-definitions directory
    const files = readdirSync(AWARD_DEFINITIONS_DIR)
      .filter(f => f.endsWith('.json'))
      .sort();

    for (const file of files) {
      try {
        const filePath = join(AWARD_DEFINITIONS_DIR, file);
        const content = readFileSync(filePath, 'utf-8');
        const definition = JSON.parse(content);
        definitions.push(definition);
      } catch (error) {
        logger.warn('Failed to load award definition', { file, error: error.message });
      }
    }
  } catch (error) {
    logger.error('Error loading award definitions', { error: error.message });
  }

  // Cache the definitions for future calls
  cachedAwardDefinitions = definitions;

  return definitions;
}

/**
 * Get all available awards
 */
export async function getAllAwards() {
  const definitions = loadAwardDefinitions();

  return definitions.map((def) => ({
    id: def.id,
    name: def.name,
    description: def.description,
    caption: def.caption,
    category: def.category,
    rules: def.rules,
  }));
}

/**
 * Calculate award progress for a user
 * @param {number} userId - User ID
 * @param {Object} award - Award definition
 * @param {Object} options - Options
 * @param {boolean} options.includeDetails - Include detailed entity breakdown
 */
export async function calculateAwardProgress(userId, award, options = {}) {
  const { includeDetails = false } = options;
  let { rules } = award;

  // Normalize rules inline to handle different formats
  // Handle "filtered" type awards (like DXCC CW)
  if (rules.type === 'filtered' && rules.baseRule) {
    rules = {
      type: 'entity',
      entityType: rules.baseRule.entityType,
      target: rules.baseRule.target,
      displayField: rules.baseRule.displayField,
      filters: rules.filters,
    };
  }
  // Handle "counter" type awards (like RS-44)
  else if (rules.type === 'counter') {
    rules = {
      type: 'entity',
      entityType: rules.countBy === 'qso' ? 'callsign' : 'callsign',
      target: rules.target,
      displayField: rules.displayField,
      filters: rules.filters,
    };
  }
  // Validate "points" type awards
  else if (rules.type === 'points') {
    if (!rules.stations || !Array.isArray(rules.stations)) {
      logger.warn('Point-based award missing stations array');
    }
  }

  logger.debug('Calculating award progress', {
    userId,
    awardId: award.id,
    awardType: rules.type,
    entityType: rules.entityType,
    hasFilters: !!rules.filters,
  });

  // Handle DOK-based awards (DLD)
  if (rules.type === 'dok') {
    return calculateDOKAwardProgress(userId, award, { includeDetails });
  }

  // Handle point-based awards
  if (rules.type === 'points') {
    return calculatePointsAwardProgress(userId, award, { includeDetails });
  }

  // Get all QSOs for user
  const allQSOs = await db
    .select()
    .from(qsos)
    .where(eq(qsos.userId, userId));

  logger.debug('Total QSOs for user', { count: allQSOs.length });

  // Apply filters if defined
  let filteredQSOs = allQSOs;
  if (rules.filters) {
    filteredQSOs = applyFilters(allQSOs, rules.filters);
    logger.debug('QSOs after filters', { count: filteredQSOs.length });
  }

  // Apply allowed_bands filter if present
  let finalQSOs = filteredQSOs;
  if (rules.allowed_bands && Array.isArray(rules.allowed_bands) && rules.allowed_bands.length > 0) {
    finalQSOs = filteredQSOs.filter(qso => {
      const band = qso.band;
      return rules.allowed_bands.includes(band);
    });
    logger.debug('QSOs after allowed_bands filter', { count: finalQSOs.length });
  }

  // Apply satellite_only filter if present
  if (rules.satellite_only) {
    finalQSOs = finalQSOs.filter(qso => qso.satName);
    logger.debug('QSOs after satellite_only filter', { count: finalQSOs.length });
  }

  // Calculate worked and confirmed entities
  const workedEntities = new Set();
  const confirmedEntities = new Set();

  for (const qso of finalQSOs) {
    const entity = getEntityValue(qso, rules.entityType);

    if (entity) {
      // Worked: QSO exists (any LoTW status)
      workedEntities.add(entity);

      // Confirmed: LoTW QSL received
      if (qso.lotwQslRstatus === 'Y') {
        confirmedEntities.add(entity);
      }
    }
  }

  return {
    worked: workedEntities.size,
    confirmed: confirmedEntities.size,
    target: rules.target || 0,
    percentage: rules.target ? Math.round((confirmedEntities.size / rules.target) * 100) : 0,
    workedEntities: Array.from(workedEntities),
    confirmedEntities: Array.from(confirmedEntities),
  };
}

/**
 * Calculate progress for DOK-based awards (DLD)
 * Counts unique (DOK, band, mode) combinations with DCL confirmation
 * @param {number} userId - User ID
 * @param {Object} award - Award definition
 * @param {Object} options - Options
 * @param {boolean} options.includeDetails - Include detailed entity breakdown
 */
async function calculateDOKAwardProgress(userId, award, options = {}) {
  const { includeDetails = false } = options;
  const { rules } = award;
  const { target, displayField, filters } = rules;

  logger.debug('Calculating DOK-based award progress', { userId, awardId: award.id, target, hasFilters: !!filters });

  // Get all QSOs for user
  const allQSOs = await db
    .select()
    .from(qsos)
    .where(eq(qsos.userId, userId));

  logger.debug('Total QSOs for user', { count: allQSOs.length });

  // Apply filters if defined
  let filteredQSOs = allQSOs;
  if (filters) {
    filteredQSOs = applyFilters(allQSOs, filters);
    logger.debug('QSOs after DOK award filters', { count: filteredQSOs.length });
  }

  // Track unique (DOK, band, mode) combinations
  const dokCombinations = new Map(); // Key: "DOK/band/mode" -> detail object with qsos array

  for (const qso of filteredQSOs) {
    const dok = qso.darcDok;
    if (!dok) continue; // Skip QSOs without DOK

    const band = qso.band || 'Unknown';
    const mode = qso.mode || 'Unknown';
    const combinationKey = `${dok}/${band}/${mode}`;

    // Initialize combination if not exists
    if (!dokCombinations.has(combinationKey)) {
      dokCombinations.set(combinationKey, {
        entity: dok,
        entityId: null,
        entityName: dok,
        band,
        mode,
        worked: false,
        confirmed: false,
        qsos: [], // Array of confirmed QSOs for this slot
      });
    }

    const detail = dokCombinations.get(combinationKey);
    detail.worked = true;

    // Check for DCL confirmation and add to qsos array
    if (qso.dclQslRstatus === 'Y') {
      if (!detail.confirmed) {
        detail.confirmed = true;
      }
      // Add this confirmed QSO to the qsos array
      detail.qsos.push({
        qsoId: qso.id,
        callsign: qso.callsign,
        mode: qso.mode,
        qsoDate: qso.qsoDate,
        timeOn: qso.timeOn,
        band: qso.band,
        satName: qso.satName,
        confirmed: true,
      });
    }
  }

  const workedDOKs = new Set();
  const confirmedDOKs = new Set();

  for (const [key, detail] of dokCombinations) {
    const dok = detail.entity;
    workedDOKs.add(dok);
    if (detail.confirmed) {
      confirmedDOKs.add(dok);
    }
  }

  logger.debug('DOK award progress', {
    workedDOKs: workedDOKs.size,
    confirmedDOKs: confirmedDOKs.size,
    target,
  });

  // Base result
  const result = {
    worked: workedDOKs.size,
    confirmed: confirmedDOKs.size,
    target: target || 0,
    percentage: target ? Math.round((confirmedDOKs.size / target) * 100) : 0,
    workedEntities: Array.from(workedDOKs),
    confirmedEntities: Array.from(confirmedDOKs),
  };

  // Add details if requested
  if (includeDetails) {
    result.award = {
      id: award.id,
      name: award.name,
      description: award.description,
      caption: award.caption,
      target: target || 0,
    };
    result.entities = Array.from(dokCombinations.values());
    result.total = result.entities.length;
    result.confirmed = result.entities.filter((e) => e.confirmed).length;
  }

  return result;
}

/**
 * Calculate progress for point-based awards
 * countMode determines how points are counted:
 * - "perBandMode": each unique (callsign, band, mode) combination earns points
 * - "perStation": each unique station earns points once
 * - "perQso": every confirmed QSO earns points
 * @param {number} userId - User ID
 * @param {Object} award - Award definition
 * @param {Object} options - Options
 * @param {boolean} options.includeDetails - Include detailed entity breakdown
 */
async function calculatePointsAwardProgress(userId, award, options = {}) {
  const { includeDetails = false } = options;
  const { rules } = award;
  const { stations, target, countMode = 'perStation' } = rules;

  // Create a map of callsign -> points for quick lookup
  const stationPoints = new Map();
  for (const station of stations) {
    stationPoints.set(station.callsign.toUpperCase(), station.points);
  }

  logger.debug('Point-based award stations', {
    totalStations: stations.length,
    countMode,
    maxPoints: stations.reduce((sum, s) => sum + s.points, 0),
  });

  // Get all QSOs for user
  const allQSOs = await db
    .select()
    .from(qsos)
    .where(eq(qsos.userId, userId));

  const workedStations = new Set();
  let totalPoints = 0;
  const stationDetails = [];

  if (countMode === 'perBandMode') {
    // Count unique (callsign, band, mode) combinations
    const combinationMap = new Map();

    for (const qso of allQSOs) {
      const callsign = qso.callsign?.toUpperCase();
      if (!callsign) continue;

      const points = stationPoints.get(callsign);
      if (!points) continue;

      const band = qso.band || 'Unknown';
      const mode = qso.mode || 'Unknown';
      const combinationKey = `${callsign}/${band}/${mode}`;

      workedStations.add(callsign);

      if (!combinationMap.has(combinationKey)) {
        combinationMap.set(combinationKey, {
          callsign,
          band,
          mode,
          points,
          worked: true,
          confirmed: false,
          qsos: [], // Array of confirmed QSOs for this slot
        });
      }

      if (qso.lotwQslRstatus === 'Y') {
        const detail = combinationMap.get(combinationKey);
        if (!detail.confirmed) {
          detail.confirmed = true;
        }
        // Add this confirmed QSO to the qsos array
        detail.qsos.push({
          qsoId: qso.id,
          callsign: qso.callsign,
          mode: qso.mode,
          qsoDate: qso.qsoDate,
          timeOn: qso.timeOn,
          band: qso.band,
          satName: qso.satName,
          confirmed: true,
        });
      }
    }

    const details = Array.from(combinationMap.values());
    stationDetails.push(...details);
    totalPoints = details.filter((d) => d.confirmed).reduce((sum, d) => sum + d.points, 0);
  } else if (countMode === 'perStation') {
    // Count unique stations only
    const stationMap = new Map();

    for (const qso of allQSOs) {
      const callsign = qso.callsign?.toUpperCase();
      if (!callsign) continue;

      const points = stationPoints.get(callsign);
      if (!points) continue;

      workedStations.add(callsign);

      if (!stationMap.has(callsign)) {
        stationMap.set(callsign, {
          callsign,
          points,
          worked: true,
          confirmed: false,
          qsos: [], // Array of confirmed QSOs for this station
        });
      }

      if (qso.lotwQslRstatus === 'Y') {
        const detail = stationMap.get(callsign);
        if (!detail.confirmed) {
          detail.confirmed = true;
        }
        // Add this confirmed QSO to the qsos array
        detail.qsos.push({
          qsoId: qso.id,
          callsign: qso.callsign,
          mode: qso.mode,
          qsoDate: qso.qsoDate,
          timeOn: qso.timeOn,
          band: qso.band,
          satName: qso.satName,
          confirmed: true,
        });
      }
    }

    const details = Array.from(stationMap.values());
    stationDetails.push(...details);
    totalPoints = details.filter((d) => d.confirmed).reduce((sum, d) => sum + d.points, 0);
  } else if (countMode === 'perQso') {
    // Count every confirmed QSO
    for (const qso of allQSOs) {
      const callsign = qso.callsign?.toUpperCase();
      if (!callsign) continue;

      const points = stationPoints.get(callsign);
      if (!points) continue;

      workedStations.add(callsign);

      if (qso.lotwQslRstatus === 'Y') {
        totalPoints += points;
        // For perQso mode, each QSO is its own slot with a qsos array containing just itself
        stationDetails.push({
          qsoId: qso.id,
          callsign,
          points,
          worked: true,
          confirmed: true,
          qsoDate: qso.qsoDate,
          band: qso.band,
          mode: qso.mode,
          qsos: [{
            qsoId: qso.id,
            callsign: qso.callsign,
            mode: qso.mode,
            qsoDate: qso.qsoDate,
            timeOn: qso.timeOn,
            band: qso.band,
            satName: qso.satName,
            confirmed: true,
          }],
        });
      }
    }
  }

  logger.debug('Point-based award progress', {
    workedStations: workedStations.size,
    totalPoints,
    target,
  });

  // Base result
  const result = {
    worked: workedStations.size,
    confirmed: stationDetails.filter((s) => s.confirmed).length,
    totalPoints,
    target: target || 0,
    percentage: target ? Math.min(100, Math.round((totalPoints / target) * 100)) : 0,
    workedEntities: Array.from(workedStations),
    confirmedEntities: stationDetails.filter((s) => s.confirmed).map((s) => s.callsign),
  };

  // Add details if requested
  if (includeDetails) {
    // Convert stationDetails to entity format for breakdown
    const entities = stationDetails.map((detail) => {
      if (countMode === 'perBandMode') {
        return {
          qsoId: detail.qsoId,
          entity: `${detail.callsign}/${detail.band}/${detail.mode}`,
          entityId: null,
          entityName: `${detail.callsign} (${detail.band}/${detail.mode})`,
          points: detail.points,
          worked: detail.worked,
          confirmed: detail.confirmed,
          qsoDate: detail.qsoDate,
          band: detail.band,
          mode: detail.mode,
          callsign: detail.callsign,
          lotwQslRdate: detail.lotwQslRdate,
          qsos: detail.qsos || [], // All confirmed QSOs for this slot
        };
      } else if (countMode === 'perStation') {
        return {
          qsoId: detail.qsoId,
          entity: detail.callsign,
          entityId: null,
          entityName: detail.callsign,
          points: detail.points,
          worked: detail.worked,
          confirmed: detail.confirmed,
          qsoDate: detail.qsoDate,
          band: detail.band,
          mode: detail.mode,
          callsign: detail.callsign,
          lotwQslRdate: detail.lotwQslRdate,
          qsos: detail.qsos || [], // All confirmed QSOs for this station
        };
      } else {
        return {
          qsoId: detail.qsoId,
          entity: `${detail.callsign}-${detail.qsoDate}`,
          entityId: null,
          entityName: `${detail.callsign} on ${detail.qsoDate}`,
          points: detail.points,
          worked: detail.worked,
          confirmed: detail.confirmed,
          qsoDate: detail.qsoDate,
          band: detail.band,
          mode: detail.mode,
          callsign: detail.callsign,
          lotwQslRdate: detail.lotwQslRdate,
          qsos: detail.qsos || [], // All confirmed QSOs for this slot (just this one QSO)
        };
      }
    });

    result.award = {
      id: award.id,
      name: award.name,
      description: award.description,
      caption: award.caption,
      target: award.rules?.target || 0,
    };
    result.entities = entities;
    result.total = entities.length;
    result.confirmed = entities.filter((e) => e.confirmed).length;
  } else {
    result.stationDetails = stationDetails;
  }

  return result;
}

/**
 * Get entity value from QSO based on entity type
 */
function getEntityValue(qso, entityType) {
  switch (entityType) {
    case 'dxcc':
      return qso.entityId;
    case 'state':
      return qso.state;
    case 'grid':
      // For VUCC, use first 4 characters of grid
      return qso.grid ? qso.grid.substring(0, 4) : null;
    case 'callsign':
      return qso.callsign;
    default:
      return null;
  }
}

/**
 * Apply filters to QSOs based on award rules
 */
function applyFilters(qsos, filters) {
  if (!filters || !filters.filters) {
    return qsos;
  }

  return qsos.filter((qso) => {
    if (filters.operator === 'AND') {
      return filters.filters.every((filter) => matchesFilter(qso, filter));
    } else if (filters.operator === 'OR') {
      return filters.filters.some((filter) => matchesFilter(qso, filter));
    }
    return true;
  });
}

/**
 * Check if a QSO matches a filter
 */
function matchesFilter(qso, filter) {
  let value;

  // Special handling for satellite field
  if (filter.field === 'satellite') {
    // Check if it's a satellite QSO (has satName)
    value = qso.satName && qso.satName.length > 0;
  } else {
    value = qso[filter.field];
  }

  switch (filter.operator) {
    case 'eq':
      return value === filter.value;
    case 'ne':
      return value !== filter.value;
    case 'in':
      return Array.isArray(filter.value) && filter.value.includes(value);
    case 'nin':
      return Array.isArray(filter.value) && !filter.value.includes(value);
    case 'contains':
      return value && typeof value === 'string' && value.toLowerCase().includes(filter.value.toLowerCase());
    default:
      return true;
  }
}

/**
 * Get award progress with QSO details
 */
export async function getAwardProgressDetails(userId, awardId) {
  // Check cache first
  const cached = getCachedAwardProgress(userId, awardId);
  if (cached) {
    logger.debug(`Cache hit for award ${awardId}, user ${userId}`);
    return cached;
  }

  logger.debug(`Cache miss for award ${awardId}, user ${userId} - calculating...`);

  // Get award definition
  const definitions = loadAwardDefinitions();
  const award = definitions.find((def) => def.id === awardId);

  if (!award) {
    return null;
  }

  // Calculate progress
  const progress = await calculateAwardProgress(userId, award);

  const result = {
    award: {
      id: award.id,
      name: award.name,
      description: award.description,
      caption: award.caption,
      category: award.category,
    },
    ...progress,
  };

  // Store in cache
  setCachedAwardProgress(userId, awardId, result);

  return result;
}

/**
 * Get detailed entity breakdown for an award
 */
export async function getAwardEntityBreakdown(userId, awardId) {
  const definitions = loadAwardDefinitions();
  const award = definitions.find((def) => def.id === awardId);

  if (!award) {
    return null;
  }

  let { rules } = award;

  // Normalize rules inline
  if (rules.type === 'filtered' && rules.baseRule) {
    rules = {
      type: 'entity',
      entityType: rules.baseRule.entityType,
      target: rules.baseRule.target,
      displayField: rules.baseRule.displayField,
      filters: rules.filters,
    };
  } else if (rules.type === 'counter') {
    rules = {
      type: 'entity',
      entityType: rules.countBy === 'qso' ? 'callsign' : 'callsign',
      target: rules.target,
      displayField: rules.displayField,
      filters: rules.filters,
    };
  }

  // Handle DOK-based awards - use the dedicated function
  if (rules.type === 'dok') {
    return await calculateDOKAwardProgress(userId, award, { includeDetails: true });
  }

  // Handle point-based awards - use the unified function
  if (rules.type === 'points') {
    return await calculatePointsAwardProgress(userId, award, { includeDetails: true });
  }

  // Get all QSOs for user
  const allQSOs = await db
    .select()
    .from(qsos)
    .where(eq(qsos.userId, userId));

  // Apply filters
  const filteredQSOs = applyFilters(allQSOs, rules.filters);

  // Apply allowed_bands filter if present
  let finalQSOs = filteredQSOs;
  if (rules.allowed_bands && Array.isArray(rules.allowed_bands) && rules.allowed_bands.length > 0) {
    finalQSOs = filteredQSOs.filter(qso => {
      const band = qso.band;
      return rules.allowed_bands.includes(band);
    });
  }

  // Apply satellite_only filter if present
  if (rules.satellite_only) {
    finalQSOs = finalQSOs.filter(qso => qso.satName);
  }

  // Group by (entity, band, mode) slot for entity awards
  // This allows showing multiple QSOs per entity on different bands/modes
  const slotMap = new Map(); // Key: "entity/band/mode" -> slot object

  for (const qso of finalQSOs) {
    const entity = getEntityValue(qso, rules.entityType);

    if (!entity) continue;

    const band = qso.band || 'Unknown';
    const mode = qso.mode || 'Unknown';
    const slotKey = `${entity}/${band}/${mode}`;

    // Determine what to display as the entity name (only on first create)
    let displayName = String(entity);
    if (rules.displayField) {
      let rawValue = qso[rules.displayField];
      if (rules.displayField === 'grid' && rawValue && rawValue.length > 4) {
        rawValue = rawValue.substring(0, 4);
      }
      displayName = String(rawValue || entity);
    } else {
      displayName = qso.entity || qso.state || qso.grid || qso.callsign || String(entity);
    }

    if (!slotMap.has(slotKey)) {
      slotMap.set(slotKey, {
        entity,
        entityId: qso.entityId,
        entityName: displayName,
        band,
        mode,
        worked: false,
        confirmed: false,
        qsos: [], // Array of confirmed QSOs for this slot
      });
    }

    const slotData = slotMap.get(slotKey);
    slotData.worked = true;

    // Check for LoTW confirmation and add to qsos array
    if (qso.lotwQslRstatus === 'Y') {
      if (!slotData.confirmed) {
        slotData.confirmed = true;
      }
      // Add this confirmed QSO to the qsos array
      slotData.qsos.push({
        qsoId: qso.id,
        callsign: qso.callsign,
        mode: qso.mode,
        qsoDate: qso.qsoDate,
        timeOn: qso.timeOn,
        band: qso.band,
        satName: qso.satName,
        confirmed: true,
      });
    }
  }

  return {
    award: {
      id: award.id,
      name: award.name,
      description: award.description,
      caption: award.caption,
      target: rules.target || 0,
    },
    entities: Array.from(slotMap.values()),
    total: slotMap.size,
    confirmed: Array.from(slotMap.values()).filter((e) => e.confirmed).length,
  };
}