const queue = require('../queue/sqliteQueue');
const logger = require('../utils/logger');
const { normalize } = require('../normalizers');
const { dedupeKey } = require('../utils/hash');
const instrumentService = require('../instrumentConfig/service');

const parserMap = {
  'http-json': require('../parsers/httpParser'),
  'hl7-tcp': require('../parsers/hl7Parser'),
  'astm-serial': require('../parsers/astmParser'),
  hl7: require('../parsers/hl7Parser'),
  astm: require('../parsers/astmParser'),
  http: require('../parsers/httpParser')
};

function resolveParser(connector, instrumentEntry) {
  const parserName = instrumentEntry?.translator?.parser || connector;
  const parser = parserMap[parserName];
  if (!parser) {
    throw new Error(`no parser registered for ${parserName}`);
  }
  return parser;
}

async function processMessage(connector, rawPayload, context = {}) {
  const rawRecord = await queue.insertRaw(connector, rawPayload);
  const rawId = rawRecord?.lastID;
  try {
    const matcher = instrumentService.resolveForMessage(connector, context);
    if (matcher.status === 'no_match') {
      logger.warn({ connector, context }, 'no matching instrument config, dropping payload');
      await queue.markRawParsed(rawId, 'dropped', 'no matching instrument config');
      return { dropped: true };
    }
    if (matcher.status === 'ambiguous') {
      logger.warn({ connector, context, matches: matcher.matches }, 'ambiguous instrument match, dropping payload');
      await queue.markRawParsed(rawId, 'dropped', 'ambiguous instrument match');
      return { dropped: true };
    }

    const instrumentEntry = matcher.entry;
    const parser = resolveParser(connector, instrumentEntry);
    const parsed = await parser.parse(rawPayload);
    const translated = instrumentService.applyTranslator(instrumentEntry, parsed, connector);
    const canonical = normalize(translated);
    const dedupe = dedupeKey(canonical);
    const inserted = await queue.insertOutbox(canonical, dedupe);
    await queue.markRawParsed(rawId, 'processed');
    if (inserted && inserted.duplicate) {
      logger.info({ dedupe, connector }, 'duplicate payload detected');
    }
    return { canonical, inserted, dedupe };
  } catch (error) {
    logger.error({ err: error.message, connector }, 'message processing failed');
    if (rawId) {
      await queue.markRawParsed(rawId, 'failed', error.message);
    }
    throw error;
  }
}

module.exports = { processMessage };