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

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

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

/**
 * Load all award definitions
 */
function loadAwardDefinitions() {
  const definitions = [];

  try {
    const files = [
      'dxcc.json',
      'dxcc-cw.json',
      'was.json',
      'vucc-sat.json',
      'sat-rs44.json',
    ];

    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 });
  }

  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,
    category: def.category,
    rules: def.rules,
  }));
}

/**
 * Normalize award rules to a consistent format
 */
function normalizeAwardRules(rules) {
  // Handle "filtered" type awards (like DXCC CW)
  if (rules.type === 'filtered' && rules.baseRule) {
    return {
      type: 'entity',
      entityType: rules.baseRule.entityType,
      target: rules.baseRule.target,
      filters: rules.filters,
    };
  }

  // Handle "counter" type awards (like RS-44)
  // These count unique callsigns instead of entities
  if (rules.type === 'counter') {
    return {
      type: 'entity',
      entityType: rules.countBy === 'qso' ? 'callsign' : 'callsign',
      target: rules.target,
      filters: rules.filters,
    };
  }

  return rules;
}

/**
 * Calculate award progress for a user
 * @param {number} userId - User ID
 * @param {Object} award - Award definition
 */
export async function calculateAwardProgress(userId, award) {
  let { rules } = award;

  // Normalize rules to handle different formats
  rules = normalizeAwardRules(rules);

  logger.debug('Calculating award progress', {
    userId,
    awardId: award.id,
    awardType: rules.type,
    entityType: rules.entityType,
    hasFilters: !!rules.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 (rules.filters) {
    filteredQSOs = applyFilters(allQSOs, rules.filters);
    logger.debug('QSOs after filters', { count: filteredQSOs.length });
  }

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

  for (const qso of filteredQSOs) {
    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),
  };
}

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

  if (!award) {
    throw new Error('Award not found');
  }

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

  return {
    award: {
      id: award.id,
      name: award.name,
      description: award.description,
      category: award.category,
    },
    ...progress,
  };
}

/**
 * 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) {
    throw new Error('Award not found');
  }

  let { rules } = award;

  // Normalize rules to handle different formats
  rules = normalizeAwardRules(rules);

  // 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);

  // Group by entity
  const entityMap = new Map();

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

    if (!entity) continue;

    if (!entityMap.has(entity)) {
      entityMap.set(entity, {
        entity,
        entityId: qso.entityId,
        worked: false,
        confirmed: false,
        qsoDate: qso.qsoDate,
        band: qso.band,
        mode: qso.mode,
        callsign: qso.callsign,
      });
    }

    const entityData = entityMap.get(entity);
    entityData.worked = true;

    if (qso.lotwQslRstatus === 'Y') {
      entityData.confirmed = true;
      entityData.lotwQslRdate = qso.lotwQslRdate;
    }
  }

  return {
    award: {
      id: award.id,
      name: award.name,
      description: award.description,
    },
    entities: Array.from(entityMap.values()),
    total: entityMap.size,
    confirmed: Array.from(entityMap.values()).filter((e) => e.confirmed).length,
  };
}