import {config} from '../src/config.js';
import {setupRules} from '../libraries/mspa/activityControls.js';
import {deepSetValue, prefixLog} from '../src/utils.js';

const FIELDS = {
  Version: 0,
  Gpc: 0,
  SharingNotice: 0,
  SaleOptOutNotice: 0,
  SharingOptOutNotice: 0,
  TargetedAdvertisingOptOutNotice: 0,
  SensitiveDataProcessingOptOutNotice: 0,
  SensitiveDataLimitUseNotice: 0,
  SaleOptOut: 0,
  SharingOptOut: 0,
  TargetedAdvertisingOptOut: 0,
  SensitiveDataProcessing: 12,
  KnownChildSensitiveDataConsents: 2,
  PersonalDataConsents: 0,
  MspaCoveredTransaction: 0,
  MspaOptOutOptionMode: 0,
  MspaServiceProviderMode: 0,
};

/**
 * Generate a normalization function for converting US state strings to the usnat format.
 *
 * Scalar fields are copied over if they exist in the input (state) data, or set to null otherwise.
 * List fields are also copied, but forced to the "correct" length (by truncating or padding with nulls);
 * additionally, elements within them can be moved around using the `move` argument.
 */
export function normalizer({nullify = [], move = {}, fn}: {
  /**
   * list of fields to force to null
   */
  nullify?: string[];
  /**
   * Map from list field name to an index remapping for elements within that field (using 1 as the first index).
   * For example, {SensitiveDataProcessing: {1: 2, 2: [1, 3]}} means "rearrange SensitiveDataProcessing by moving
   * the first element to the second position, and the second element to both the first and third position."
   */
  move?: { [name: string]: { [position: number]: number | number[] } };
  /**
   * an optional function to run once all the processing described above is complete;
   * it's passed two arguments, the original (state) data, and its normalized (usnat) version.
   */
  fn?: (original, normalized) => any;
}, fields = FIELDS) {
  move = Object.fromEntries(Object.entries(move).map(([k, map]) => [k,
    Object.fromEntries(Object.entries(map)
      .map(([k, v]) => [k, Array.isArray(v) ? v : [v]])
      .map(([k, v]: [any, any]) => [--k, v.map(el => --el)])
    )])
  );
  return function (cd) {
    const norm = Object.fromEntries(Object.entries(fields)
      .map(([field, len]) => {
        let val = null;
        if (len > 0) {
          val = Array(len).fill(null);
          if (Array.isArray(cd[field])) {
            const remap = (move[field] || {}) as Record<number, number[]>;
            const done = [];
            cd[field].forEach((el, i) => {
              const [dest, moved] = remap.hasOwnProperty(i) ? [remap[i], true] : [[i], false];
              dest.forEach(d => {
                if (d < len && !done.includes(d)) {
                  val[d] = el;
                  moved && done.push(d);
                }
              });
            });
          }
        } else if (cd[field] != null) {
          val = Array.isArray(cd[field]) ? null : cd[field];
        }
        return [field, val];
      }));
    nullify.forEach(path => deepSetValue(norm, path, null));
    fn && fn(cd, norm);
    return norm;
  };
}

function scalarMinorsAreChildren(original, normalized) {
  normalized.KnownChildSensitiveDataConsents = original.KnownChildSensitiveDataConsents === 0 ? [0, 0] : [1, 1];
}

export const NORMALIZATIONS = {
  // normalization rules - convert state consent into usnat consent
  // https://docs.prebid.org/features/mspa-usnat.html
  7: (consent) => consent,
  8: normalizer({
    move: {
      SensitiveDataProcessing: {
        1: 9,
        2: 10,
        3: 8,
        4: [1, 2],
        5: 12,
        8: 3,
        9: 4,
      }
    },
    fn(original, normalized) {
      if (original.KnownChildSensitiveDataConsents.some(el => el !== 0)) {
        normalized.KnownChildSensitiveDataConsents = [1, 1];
      }
    }
  }),
  9: normalizer({fn: scalarMinorsAreChildren}),
  10: normalizer({fn: scalarMinorsAreChildren}),
  11: normalizer({
    move: {
      SensitiveDataProcessing: {
        3: 4,
        4: 5,
        5: 3,
      }
    },
    fn: scalarMinorsAreChildren
  }),
  12: normalizer({
    fn(original, normalized) {
      const cc = original.KnownChildSensitiveDataConsents;
      let repl;
      if (!cc.some(el => el !== 0)) {
        repl = [0, 0];
      } else if (cc[1] === 2 && cc[2] === 2) {
        repl = [2, 1];
      } else {
        repl = [1, 1];
      }
      normalized.KnownChildSensitiveDataConsents = repl;
    }
  })
};

export const DEFAULT_SID_MAPPING = {
  8: 'usca',
  9: 'usva',
  10: 'usco',
  11: 'usut',
  12: 'usct'
};

export const getSections = (() => {
  const allSIDs = Object.keys(DEFAULT_SID_MAPPING).map(Number);
  return function ({sections = {}, sids = allSIDs} = {}) {
    return sids.map(sid => {
      const logger = prefixLog(`Cannot set up MSPA controls for SID ${sid}:`);
      const ov = sections[sid] || {};
      const normalizeAs = ov.normalizeAs || sid;
      if (!NORMALIZATIONS.hasOwnProperty(normalizeAs)) {
        logger.logError(`no normalization rules are known for SID ${normalizeAs}`)
        return;
      }
      const api = ov.name || DEFAULT_SID_MAPPING[sid];
      if (typeof api !== 'string') {
        logger.logError(`cannot determine GPP section name`)
        return;
      }
      return [
        api,
        [sid],
        NORMALIZATIONS[normalizeAs]
      ]
    }).filter(el => el != null);
  }
})();

const handles = [];

declare module './consentManagementGpp' {
  interface GPPConfig {
    mspa?: {
      /**
       * GPP SIDs that should be covered by activity restrictions. Defaults to all US state SIDs.
       */
      sids?: number[];
      /**
       * Map from section ID to per-section configuration options
       */
      sections?: {
        [sid: number]: {
          /**
           * GPP API name to use for the section. Defaults to the names listed in the GPP spec:
           * https://github.com/InteractiveAdvertisingBureau/Global-Privacy-Platform/blob/main/Sections/Section%20Information.md#section-ids
           * This option would only be used if your CMP has named their sections in a non-standard way.y
           */
          name?: string;
          /**
           * Normalize the flags for this section as if it were the number provided.
           * Cfr https://docs.prebid.org/features/mspa-usnat.html#interpreting-usnat-strings
           * Each section defaults to its own ID.
           */
          normalizeAs?: number;
        }
      }
    }
  }
}

config.getConfig('consentManagement', (cfg) => {
  const gppConf = cfg.consentManagement?.gpp;
  if (gppConf) {
    while (handles.length) {
      handles.pop()();
    }
    getSections(gppConf?.mspa || {})
      .forEach(([api, sids, normalize]) => handles.push(setupRules(api, sids, normalize)));
  }
});