import { ObjectId } from 'mongodb';
import { auditLogModel } from './database/schemas/management/auditlog.schema.js';
import exifr from 'exifr';
import { natsServer } from './database/nats.js';
import log4js from 'log4js';
import config from './config.js';
import crypto from 'crypto';
import canonicalize from 'canonical-json';

const logger = log4js.getLogger('Utils');
logger.level = config.server.logLevel;

function buildWildcardRegexPattern(input) {
  // Escape all regex special chars except * (which we treat as a wildcard)
  const escaped = input.replace(/[.+?^${}()|[\]\\]/g, '\\$&');
  // Convert * to "match anything"
  const withWildcards = escaped.replace(/\*/g, '.*');
  // Anchor so that, without *, this is an exact match
  return `^${withWildcards}$`;
}

function parseFilter(property, value) {
  if (typeof value === 'string') {
    var trimmed = value.trim();
    if (trimmed.charAt(3) == ':') {
      trimmed = value.split(':')[1];
    }

    // Handle booleans
    if (trimmed.toLowerCase() === 'true') return { [property]: true };
    if (trimmed.toLowerCase() === 'false') return { [property]: false };

    // Handle ObjectId (24-char hex)

    if (/^[a-f\d]{24}$/i.test(trimmed) && trimmed.length >= 24) {
      return { [property]: new ObjectId(trimmed) };
    }

    // Handle numbers
    if (!isNaN(trimmed)) {
      return { [property]: parseFloat(trimmed) };
    }

    // Default to case-insensitive regex for non-numeric strings.
    // Supports * as a wildcard (e.g. "filament*" matches "filament stock").
    const pattern = buildWildcardRegexPattern(trimmed);
    return {
      [property]: {
        $regex: pattern,
        $options: 'i',
      },
    };
  }

  // Handle actual booleans, numbers, objects, etc.
  return { [property]: value };
}

function convertToCamelCase(obj) {
  const result = {};

  for (const key in obj) {
    if (Object.prototype.hasOwnProperty.call(obj, key)) {
      const value = obj[key];

      // Convert the key to camelCase
      let camelKey = key
        // First handle special cases with spaces, brackets and other characters
        .replace(/\s*\[.*?\]\s*/g, '') // Remove brackets and their contents
        .replace(/\s+/g, ' ') // Normalize spaces
        .trim()
        // Split by common separators (space, underscore, hyphen)
        .split(/[\s_-]/)
        // Convert to camelCase
        .map((word, index) => {
          // Remove any non-alphanumeric characters
          word = word.replace(/[^a-zA-Z0-9]/g, '');

          // Lowercase first word, uppercase others
          return index === 0
            ? word.toLowerCase()
            : word.charAt(0).toUpperCase() + word.slice(1).toLowerCase();
        })
        .join('');

      // Handle values that are objects recursively
      if (value !== null && typeof value === 'object' && !Array.isArray(value)) {
        result[camelKey] = convertToCamelCase(value);
      } else {
        result[camelKey] = value;
      }
    }
  }

  return result;
}

function extractGCodeConfigBlock(fileContent, useCamelCase = true) {
  const configObject = {};

  // Extract header information
  const headerBlockRegex = /; HEADER_BLOCK_START([\s\S]*?)(?:; HEADER_BLOCK_END|$)/;
  const headerBlockMatch = fileContent.match(headerBlockRegex);
  if (headerBlockMatch && headerBlockMatch[1]) {
    const headerLines = headerBlockMatch[1].split('\n');
    headerLines.forEach((line) => {
      const keyValueRegex = /^\s*;\s*([^:]+?):\s*(.*?)\s*$/;
      const simpleValueRegex = /^\s*;\s*(.*?)\s*$/;

      // Try key-value format first
      let match = line.match(keyValueRegex);
      if (match) {
        const key = match[1].trim();
        let value = match[2].trim();

        // Try to convert value to appropriate type
        if (!isNaN(value) && value !== '') {
          value = Number(value);
        }
        configObject[key] = value;
      } else {
        // Try the simple format like "; generated by OrcaSlicer 2.1.1 on 2025-04-28 at 13:30:11"
        match = line.match(simpleValueRegex);
        if (match && match[1] && !match[1].includes('HEADER_BLOCK')) {
          const text = match[1].trim();

          // Extract slicer info
          const slicerMatch = text.match(/generated by (.*?) on (.*?) at (.*?)$/);
          if (slicerMatch) {
            configObject['slicer'] = slicerMatch[1].trim();
            configObject['date'] = slicerMatch[2].trim();
            configObject['time'] = slicerMatch[3].trim();
          } else {
            // Just add as a general header entry if it doesn't match any specific pattern
            const key = `header_${Object.keys(configObject).length}`;
            configObject[key] = text;
          }
        }
      }
    });
  }

  // Extract thumbnail data
  const thumbnailBlockRegex = /; THUMBNAIL_BLOCK_START([\s\S]*?)(?:; THUMBNAIL_BLOCK_END|$)/;
  const thumbnailBlockMatch = fileContent.match(thumbnailBlockRegex);
  if (thumbnailBlockMatch && thumbnailBlockMatch[1]) {
    const thumbnailLines = thumbnailBlockMatch[1].split('\n');
    let base64Data = '';
    let thumbnailInfo = {};

    thumbnailLines.forEach((line) => {
      // Extract thumbnail dimensions and size from the line "thumbnail begin 640x640 27540"
      const thumbnailHeaderRegex = /^\s*;\s*thumbnail begin (\d+)x(\d+) (\d+)/;
      const match = line.match(thumbnailHeaderRegex);

      if (match) {
        thumbnailInfo.width = parseInt(match[1], 10);
        thumbnailInfo.height = parseInt(match[2], 10);
        thumbnailInfo.size = parseInt(match[3], 10);
      } else if (line.trim().startsWith('; ') && !line.includes('THUMBNAIL_BLOCK')) {
        // Collect base64 data (remove the leading semicolon and space and thumbnail end)
        const dataLine = line.trim().substring(2);
        if (dataLine && dataLine != 'thumbnail end') {
          base64Data += dataLine;
        }
      }
    });

    // Add thumbnail data to config object
    if (base64Data) {
      configObject.thumbnail = {
        data: base64Data,
        ...thumbnailInfo,
      };
    }
  }

  // Extract CONFIG_BLOCK
  const configBlockRegex = /; CONFIG_BLOCK_START([\s\S]*?)(?:; CONFIG_BLOCK_END|$)/;
  const configBlockMatch = fileContent.match(configBlockRegex);
  if (configBlockMatch && configBlockMatch[1]) {
    // Extract each config line
    const configLines = configBlockMatch[1].split('\n');
    // Process each line
    configLines.forEach((line) => {
      // Check if the line starts with a semicolon and has an equals sign
      const configLineRegex = /^\s*;\s*([^=]+?)\s*=\s*(.*?)\s*$/;
      const match = line.match(configLineRegex);
      if (match) {
        const key = match[1].trim();
        let value = match[2].trim();
        // Try to convert value to appropriate type
        if (value === 'true' || value === 'false') {
          value = value === 'true';
        } else if (!isNaN(value) && value !== '') {
          // Check if it's a number (but not a percentage)
          if (!value.includes('%')) {
            value = Number(value);
          }
        }
        configObject[key] = value;
      }
    });
  }

  // Extract additional variables that appear after EXECUTABLE_BLOCK_END
  const additionalVarsRegex =
    /; EXECUTABLE_BLOCK_(?:START|END)([\s\S]*?)(?:; CONFIG_BLOCK_START|$)/i;
  const additionalVarsMatch = fileContent.match(additionalVarsRegex);
  if (additionalVarsMatch && additionalVarsMatch[1]) {
    const additionalLines = additionalVarsMatch[1].split('\n');
    additionalLines.forEach((line) => {
      // Match both standard format and the special case for "total filament cost"
      const varRegex =
        /^\s*;\s*((?:filament used|filament cost|total filament used|total filament cost|total layers count|estimated printing time)[^=]*?)\s*=\s*(.*?)\s*$/;
      const match = line.match(varRegex);
      if (match) {
        const key = match[1].replace(/\[([^\]]+)\]/g, '$1').trim();
        let value = match[2].trim();
        // Clean up values - remove units in brackets and handle special cases
        if (key.includes('filament used')) {
          // Extract just the numeric value, ignoring units in brackets
          const numMatch = value.match(/(\d+\.\d+)/);
          if (numMatch) {
            value = parseFloat(numMatch[1]);
          }
        } else if (key.includes('filament cost')) {
          // Extract just the numeric value
          const numMatch = value.match(/(\d+\.\d+)/);
          if (numMatch) {
            value = parseFloat(numMatch[1]);
          }
        } else if (key.includes('total layers count')) {
          value = parseInt(value, 10);
        } else if (key.includes('estimated printing time')) {
          // Keep as string but trim any additional whitespace
          value = value.trim();
        }
        configObject[key] = value;
      }
    });
  }

  // Also extract extrusion width settings
  const extrusionWidthRegex = /;\s*(.*?)\s*extrusion width\s*=\s*(.*?)mm/g;
  let extrusionMatch;
  while ((extrusionMatch = extrusionWidthRegex.exec(fileContent)) !== null) {
    const settingName = extrusionMatch[1].trim();
    const settingValue = parseFloat(extrusionMatch[2].trim());
    configObject[`${settingName} extrusion width`] = settingValue;
  }

  // Extract additional parameters after CONFIG_BLOCK_END if they exist
  const postConfigParams = /; CONFIG_BLOCK_END\s*\n([\s\S]*?)$/;
  const postConfigMatch = fileContent.match(postConfigParams);
  if (postConfigMatch && postConfigMatch[1]) {
    const postConfigLines = postConfigMatch[1].split('\n');
    postConfigLines.forEach((line) => {
      // Match lines with format "; parameter_name = value"
      const paramRegex = /^\s*;\s*([^=]+?)\s*=\s*(.*?)\s*$/;
      const match = line.match(paramRegex);
      if (match) {
        const key = match[1].trim();
        let value = match[2].trim();

        // Try to convert value to appropriate type
        if (value === 'true' || value === 'false') {
          value = value === 'true';
        } else if (!isNaN(value) && value !== '') {
          // Check if it's a number (but not a percentage)
          if (!value.includes('%')) {
            value = Number(value);
          }
        }

        // Add to config object if not already present
        if (!configObject[key]) {
          configObject[key] = value;
        }
      }
    });
  }

  // Apply camelCase conversion if requested
  return useCamelCase ? convertToCamelCase(configObject) : configObject;
}

function getChangedValues(oldObj, newObj, old = false) {
  const changes = {};

  const combinedObj = { ...oldObj, ...newObj };

  // Check all keys in the new object
  for (const key in combinedObj) {
    // Skip if the key is _id or timestamps
    if (key === 'createdAt' || key === 'updatedAt' || key === '_id') continue;

    const oldVal = oldObj ? oldObj[key] : undefined;
    const newVal = newObj ? newObj[key] : undefined;

    // If both values are objects (but not arrays or null), recurse
    if (
      oldVal &&
      newVal &&
      typeof oldVal === 'object' &&
      typeof newVal === 'object' &&
      !Array.isArray(oldVal) &&
      !Array.isArray(newVal) &&
      oldVal !== null &&
      newVal !== null
    ) {
      if (oldVal?._id || newVal?._id) {
        if (JSON.stringify(oldVal?._id) !== JSON.stringify(newVal?._id)) {
          changes[key] = old ? oldVal : newVal;
        }
      } else {
        const nestedChanges = getChangedValues(oldVal, newVal, old);
        if (Object.keys(nestedChanges).length > 0) {
          changes[key] = nestedChanges;
        }
      }
    } else {
      // Check if both values are numbers (or can be converted to numbers)
      const oldIsNumber =
        typeof oldVal === 'number' ||
        (oldVal !== null && oldVal !== undefined && !isNaN(Number(oldVal)) && oldVal !== '');
      const newIsNumber =
        typeof newVal === 'number' ||
        (newVal !== null && newVal !== undefined && !isNaN(Number(newVal)) && newVal !== '');

      let valuesDiffer;
      if (oldIsNumber && newIsNumber) {
        // Compare numbers directly (this normalizes 7.50 to 7.5)
        valuesDiffer = Number(oldVal) !== Number(newVal);
      } else {
        // Use JSON.stringify for non-number comparisons
        valuesDiffer = JSON.stringify(oldVal) !== JSON.stringify(newVal);
      }

      if (valuesDiffer) {
        // If the old value is different from the new value, include it
        changes[key] = old ? oldVal : newVal;
      }
    }
  }

  return changes;
}

async function newAuditLog(newValue, parentId, parentType, user) {
  // Filter out createdAt and updatedAt from newValue
  const filteredNewValue = { ...newValue };
  delete filteredNewValue.createdAt;
  delete filteredNewValue.updatedAt;
  const auditLog = new auditLogModel({
    changes: {
      new: filteredNewValue,
    },
    parent: parentId,
    parentType,
    owner: user._id,
    ownerType: 'user',
    operation: 'new',
  });

  await auditLog.save();

  await distributeNew(auditLog._id, 'auditLog');
}

async function editAuditLog(oldValue, newValue, parentId, parentType, user) {
  // Get only the changed values
  const changedOldValues = getChangedValues(oldValue, newValue, true);
  const changedNewValues = getChangedValues(oldValue, newValue, false);

  // If no values changed, don't create an audit log
  if (Object.keys(changedOldValues).length === 0 || Object.keys(changedNewValues).length === 0) {
    return;
  }

  const auditLog = new auditLogModel({
    changes: {
      old: changedOldValues,
      new: changedNewValues,
    },
    parent: parentId,
    parentType,
    owner: user._id,
    ownerType: 'user',
    operation: 'edit',
  });

  await auditLog.save();

  await distributeNew(auditLog._id, 'auditLog');
}

async function deleteAuditLog(deleteValue, parentId, parentType, user) {
  const auditLog = new auditLogModel({
    changes: {
      old: deleteValue,
    },
    parent: parentId,
    parentType,
    owner: user._id,
    ownerType: 'user',
    operation: 'delete',
  });

  await auditLog.save();

  await distributeNew(auditLog._id, 'auditLog');
}

async function getAuditLogs(idOrIds) {
  if (Array.isArray(idOrIds)) {
    return auditLogModel.find({ parent: { $in: idOrIds } }).populate('owner');
  } else {
    return auditLogModel.find({ parent: idOrIds }).populate('owner');
  }
}

async function distributeUpdate(value, id, type) {
  await natsServer.publish(`${type}s.${id}.object`, value);
}

async function distributeStats(value, type) {
  await natsServer.publish(`${type}s.stats`, value);
}

async function distributeNew(value, type) {
  await natsServer.publish(`${type}s.new`, value);
}

async function distributeDelete(value, type) {
  await natsServer.publish(`${type}s.delete`, value);
}

async function distributeChildUpdate(oldValue, newValue, id, model) {
  const oldPopulatedObjects = populateObjects(oldValue, model) || [];
  const oldPopulatedObjectIds = oldPopulatedObjects.map((populate) => populate._id.toString());
  const newPopulatedObjects = populateObjects(newValue, model) || [];
  const newPopulatedObjectIds = newPopulatedObjects.map((populate) => populate._id.toString());

  for (const populated of oldPopulatedObjects) {
    if (!newPopulatedObjectIds.includes(populated._id.toString())) {
      logger.debug(
        `Distributing child update for ${populated.ref}s.${populated._id}.events.childUpdate`
      );
      await natsServer.publish(`${populated.ref}s.${populated._id}.events.childUpdate`, {
        type: 'childUpdate',
        data: { parentId: id, parentType: model.modelName },
      });
    }
  }
  for (const populated of newPopulatedObjects) {
    if (!oldPopulatedObjectIds.includes(populated._id.toString())) {
      logger.debug(
        `Distributing child update for ${populated.ref}s.${populated._id}.events.childUpdate`
      );
      await natsServer.publish(`${populated.ref}s.${populated._id}.events.childUpdate`, {
        type: 'childUpdate',
        data: { parentId: id, parentType: model.modelName },
      });
    }
  }
}

async function distributeChildDelete(value, id, model) {
  const populatedObjects = populateObjects(value, model) || [];
  for (const populated of populatedObjects) {
    logger.debug(
      `Distributing child delete for ${populated.ref}s.${populated._id}.events.childDelete`
    );
    await natsServer.publish(`${populated.ref}s.${populated._id}.events.childDelete`, {
      type: 'childDelete',
      data: { parentId: id, parentType: model.modelName },
    });
  }
}

async function distributeChildNew(value, id, model) {
  const populatedObjects = populateObjects(value, model) || [];
  for (const populated of populatedObjects) {
    logger.debug(`Distributing child new for ${populated.ref}s.${populated._id}.events.childNew`);
    await natsServer.publish(`${populated.ref}s.${populated._id}.events.childNew`, {
      type: 'childNew',
      data: { parentId: id, parentType: model.modelName },
    });
  }
}

function flatternObjectIds(object) {
  if (!object || typeof object !== 'object') {
    return object;
  }

  const result = {};

  for (const [key, value] of Object.entries(object)) {
    if (value && typeof value === 'object' && value._id) {
      // If the value is an object with _id, convert to just the _id
      result[key] = value._id;
    } else {
      // Keep primitive values as is
      result[key] = value;
    }
  }

  return result;
}

function expandObjectIds(input) {
  // Helper to check if a value is an ObjectId or a 24-char hex string
  function isObjectId(val) {
    // Check for MongoDB ObjectId instance
    if (val instanceof ObjectId) return true;
    // Check for exactly 24 hex characters (no special characters)
    if (typeof val === 'string' && /^[a-fA-F\d]{24}$/.test(val)) return true;
    return false;
  }

  // Recursive function
  function expand(value) {
    if (Array.isArray(value)) {
      return value.map(expand);
    } else if (value && typeof value === 'object' && !(value instanceof ObjectId)) {
      var result = {};
      for (const [key, val] of Object.entries(value)) {
        if (key === '_id') {
          // Do not expand keys that are already named _id
          result[key] = val;
        } else if (isObjectId(val)) {
          result[key] = { _id: val };
        } else if (Array.isArray(val)) {
          result[key] = val.map(expand);
        } else if (val instanceof Date) {
          result[key] = val;
        } else if (val && typeof val === 'object') {
          result[key] = expand(val);
        } else {
          result[key] = val;
        }
      }
      return result;
    } else if (isObjectId(value)) {
      return { _id: value };
    } else {
      return value;
    }
  }

  return expand(input);
}

// Returns a filter object based on allowed filters and req.query
function getFilter(query, allowedFilters, parse = true) {
  let filter = {};
  for (const [key, value] of Object.entries(query)) {
    if (allowedFilters.includes(key)) {
      console.log('key', key);
      console.log('value', value);
      const parsedFilter = parse ? parseFilter(key, value) : { [key]: value };
      filter = { ...filter, ...parsedFilter };
    }
  }
  return filter;
}

// Converts a properties argument (string or array) to an array of strings
function convertPropertiesString(properties) {
  if (typeof properties === 'string') {
    return properties.split(',');
  } else if (!Array.isArray(properties)) {
    return [];
  }
  return properties;
}

async function getFileMeta(file) {
  try {
    if (!file) return {};

    const originalName = file.originalname || '';
    const lowerName = originalName.toLowerCase();

    if (lowerName.endsWith('.g') || lowerName.endsWith('.gcode')) {
      const content = file.buffer ? file.buffer.toString('utf8') : '';
      if (!content) return {};
      return extractGCodeConfigBlock(content);
    }

    // Image EXIF metadata
    if (file.mimetype && file.mimetype.startsWith('image/') && file.buffer) {
      try {
        const exif = await exifr.parse(file.buffer);
        return exif || {};
      } catch (_) {
        // Ignore EXIF parse errors and fall through
      }
    }

    return {};
  } catch (_) {
    return {};
  }
}

function modelHasRef(model, refName) {
  if (!model || !model.schema) {
    return false;
  }

  let hasRef = false;
  model.schema.eachPath((pathName, schemaType) => {
    const directRef = schemaType?.options?.ref;
    const arrayRef = schemaType?.caster?.options?.ref;
    const ref = directRef || arrayRef;
    if (ref === refName) {
      hasRef = true;
    }
  });

  return hasRef;
}

function getFieldsByRef(model, refName) {
  if (!model || !model.schema) {
    return [];
  }

  const fields = [];
  model.schema.eachPath((pathName, schemaType) => {
    const directRef = schemaType?.options?.ref;
    const arrayRef = schemaType?.caster?.options?.ref;
    const ref = directRef || arrayRef;
    if (ref === refName) {
      fields.push(pathName);
    }
  });

  return fields;
}

// Build a nested populate specification by walking the schema graph,
// instead of recursing over already-populated documents.
function buildDeepPopulateSpec(object, model, populated = new Set()) {
  // prevent infinite recursion across cyclic model relationships
  if (populated.has(model.modelName)) return [];
  populated.add(model.modelName);

  const schema = model.schema;
  const populateSpec = [];

  schema.eachPath((pathname, schemaType) => {
    const directRef = schemaType.options?.ref;
    const arrayRef = schemaType.caster?.options?.ref;
    const ref = directRef || arrayRef;
    if (!ref) return;

    const refModel = model.db.model(ref);
    const childPopulate = buildDeepPopulateSpec(object, refModel, populated);

    const id = object[pathname]?._id || object[pathname];

    if (id == null || !id) return;

    if (childPopulate.length > 0) {
      populateSpec.push({ path: pathname, populate: childPopulate, ref: ref, _id: id });
    } else {
      populateSpec.push({ path: pathname, ref: ref, _id: id });
    }
  });

  return populateSpec;
}

function populateObjects(object, model, populated = new Set()) {
  const populateSpec = buildDeepPopulateSpec(object, model, populated);

  return populateSpec;
}

function jsonToCacheKey(obj) {
  const normalized = canonicalize(obj);
  const hash = crypto.createHash('sha256').update(normalized).digest('hex');
  return hash;
}

export function getQueryToCacheKey({ model, id, populate }) {
  const populateKey = [];
  if (populate) {
    const populateArray = Array.isArray(populate) ? populate : [populate];
    for (const pop of populateArray) {
      if (typeof pop === 'string') {
        populateKey.push(pop);
      } else if (typeof pop === 'object' && pop.path) {
        populateKey.push(pop.path);
      }
    }
  }
  return `${model}:${id?.toString()}-${populateKey.join(',')}`;
}

export {
  parseFilter,
  convertToCamelCase,
  newAuditLog,
  editAuditLog,
  deleteAuditLog,
  getAuditLogs,
  flatternObjectIds,
  expandObjectIds,
  distributeUpdate,
  distributeStats,
  distributeNew,
  distributeDelete,
  distributeChildUpdate,
  distributeChildDelete,
  distributeChildNew,
  getFilter, // <-- add here
  convertPropertiesString,
  getFileMeta,
  modelHasRef,
  getFieldsByRef,
  jsonToCacheKey,
};