import { ZWaveError, ZWaveErrorCodes } from "@zwave-js/core";
import {
	enumFilesRecursive,
	formatId,
	JSONObject,
	ObjectKeyMap,
	ReadonlyObjectKeyMap,
	stringify,
} from "@zwave-js/shared";
import { isArray, isObject } from "alcalzone-shared/typeguards";
import * as fs from "fs-extra";
import { pathExists, readFile, writeFile } from "fs-extra";
import JSON5 from "json5";
import path from "path";
import { clearTemplateCache, readJsonWithTemplate } from "../JsonTemplate";
import type { ConfigLogger } from "../Logger";
import { configDir, externalConfigDir } from "../utils";
import { hexKeyRegex4Digits, throwInvalidConfig } from "../utils_safe";
import {
	ConditionalAssociationConfig,
	type AssociationConfig,
} from "./AssociationConfig";
import { CompatConfig, ConditionalCompatConfig } from "./CompatConfig";
import { evaluateDeep, validateCondition } from "./ConditionalItem";
import {
	ConditionalPrimitive,
	parseConditionalPrimitive,
} from "./ConditionalPrimitive";
import {
	ConditionalDeviceMetadata,
	type DeviceMetadata,
} from "./DeviceMetadata";
import { ConditionalEndpointConfig, EndpointConfig } from "./EndpointConfig";
import {
	ConditionalParamInformation,
	ParamInformation,
} from "./ParamInformation";
import type { DeviceID, FirmwareVersionRange } from "./shared";

export interface DeviceConfigIndexEntry {
	manufacturerId: string;
	productType: string;
	productId: string;
	firmwareVersion: FirmwareVersionRange;
	rootDir?: string;
	filename: string;
}

export interface FulltextDeviceConfigIndexEntry {
	manufacturerId: string;
	manufacturer: string;
	label: string;
	description: string;
	productType: string;
	productId: string;
	firmwareVersion: FirmwareVersionRange;
	rootDir?: string;
	filename: string;
}

export type ConditionalParamInfoMap = ReadonlyObjectKeyMap<
	{ parameter: number; valueBitMask?: number },
	ConditionalParamInformation[]
>;

export type ParamInfoMap = ReadonlyObjectKeyMap<
	{ parameter: number; valueBitMask?: number },
	ParamInformation
>;

export const embeddedDevicesDir = path.join(configDir, "devices");
const fulltextIndexPath = path.join(embeddedDevicesDir, "fulltext_index.json");

export function getDevicesPaths(configDir: string): {
	devicesDir: string;
	indexPath: string;
} {
	const devicesDir = path.join(configDir, "devices");
	const indexPath = path.join(devicesDir, "index.json");
	return { devicesDir, indexPath };
}

export type DeviceConfigIndex = DeviceConfigIndexEntry[];
export type FulltextDeviceConfigIndex = FulltextDeviceConfigIndexEntry[];

async function hasChangedDeviceFiles(
	devicesRoot: string,
	dir: string,
	lastChange: Date,
): Promise<boolean> {
	// Check if there are any files BUT index.json that were changed
	// or directories that were modified
	const filesAndDirs = await fs.readdir(dir);
	for (const f of filesAndDirs) {
		const fullPath = path.join(dir, f);

		const stat = await fs.stat(fullPath);
		if (
			(dir !== devicesRoot || f !== "index.json") &&
			(stat.isFile() || stat.isDirectory()) &&
			stat.mtime > lastChange
		) {
			return true;
		} else if (stat.isDirectory()) {
			// we need to go deeper!
			if (await hasChangedDeviceFiles(devicesRoot, fullPath, lastChange))
				return true;
		}
	}
	return false;
}

/**
 * Read all device config files from a given directory and return them as index entries.
 * Does not update the index itself.
 */
async function generateIndex<T extends Record<string, unknown>>(
	devicesDir: string,
	isEmbedded: boolean,
	extractIndexEntries: (config: DeviceConfig) => T[],
	logger?: ConfigLogger,
): Promise<(T & { filename: string; rootDir?: string })[]> {
	const index: (T & { filename: string; rootDir?: string })[] = [];

	clearTemplateCache();
	const configFiles = await enumFilesRecursive(
		devicesDir,
		(file) =>
			file.endsWith(".json") &&
			!file.endsWith("index.json") &&
			!file.includes("/templates/") &&
			!file.includes("\\templates\\"),
	);

	for (const file of configFiles) {
		const relativePath = path
			.relative(devicesDir, file)
			.replace(/\\/g, "/");
		// Try parsing the file
		try {
			const config = await DeviceConfig.from(file, isEmbedded, {
				rootDir: devicesDir,
				relative: true,
			});
			// Add the file to the index
			index.push(
				...extractIndexEntries(config).map((entry) => {
					const ret: T & { filename: string; rootDir?: string } = {
						...entry,
						filename: relativePath,
					};
					// Only add the root dir to the index if necessary
					if (devicesDir !== embeddedDevicesDir) {
						ret.rootDir = devicesDir;
					}
					return ret;
				}),
			);
		} catch (e) {
			const message = `Error parsing config file ${relativePath}: ${
				(e as Error).message
			}`;
			// Crash hard during tests, just print an error when in production systems.
			// A user could have changed a config file
			if (process.env.NODE_ENV === "test" || !!process.env.CI) {
				throw new ZWaveError(message, ZWaveErrorCodes.Config_Invalid);
			} else {
				logger?.print(message, "error");
			}
		}
	}

	return index;
}

async function loadDeviceIndexShared<T extends Record<string, unknown>>(
	devicesDir: string,
	indexPath: string,
	extractIndexEntries: (config: DeviceConfig) => T[],
	logger?: ConfigLogger,
): Promise<(T & { filename: string })[]> {
	// The index file needs to be regenerated if it does not exist
	let needsUpdate = !(await pathExists(indexPath));
	let index: (T & { filename: string })[] | undefined;
	let mtimeIndex: Date | undefined;
	// ...or if cannot be parsed
	if (!needsUpdate) {
		try {
			const fileContents = await readFile(indexPath, "utf8");
			index = JSON5.parse(fileContents);
			mtimeIndex = (await fs.stat(indexPath)).mtime;
		} catch {
			logger?.print(
				"Error while parsing index file - regenerating...",
				"warn",
			);
			needsUpdate = true;
		} finally {
			if (!index) {
				logger?.print(
					"Index file was malformed - regenerating...",
					"warn",
				);
				needsUpdate = true;
			}
		}
	}

	// ...or if there were any changes in the file system
	if (!needsUpdate) {
		needsUpdate = await hasChangedDeviceFiles(
			devicesDir,
			devicesDir,
			mtimeIndex!,
		);
		if (needsUpdate) {
			logger?.print(
				"Device configuration files on disk changed - regenerating index...",
				"verbose",
			);
		}
	}

	if (needsUpdate) {
		// Read all files from disk and generate an index
		index = await generateIndex(
			devicesDir,
			true,
			extractIndexEntries,
			logger,
		);
		// Save the index to disk
		try {
			await writeFile(
				path.join(indexPath),
				`// This file is auto-generated. DO NOT edit it by hand if you don't know what you're doing!"
${stringify(index, "\t")}
`,
				"utf8",
			);
			logger?.print("Device index regenerated", "verbose");
		} catch (e) {
			logger?.print(
				`Writing the device index to disk failed: ${
					(e as Error).message
				}`,
				"error",
			);
		}
	}

	return index!;
}

/**
 * @internal
 * Loads the index file to quickly access the device configs.
 * Transparently handles updating the index if necessary
 */
export async function generatePriorityDeviceIndex(
	deviceConfigPriorityDir: string,
	logger?: ConfigLogger,
): Promise<DeviceConfigIndex> {
	return (
		await generateIndex(
			deviceConfigPriorityDir,
			false,
			(config) =>
				config.devices.map((dev) => ({
					manufacturerId: formatId(
						config.manufacturerId.toString(16),
					),
					manufacturer: config.manufacturer,
					label: config.label,
					productType: formatId(dev.productType),
					productId: formatId(dev.productId),
					firmwareVersion: config.firmwareVersion,
					rootDir: deviceConfigPriorityDir,
				})),
			logger,
		)
	).map(({ filename, ...entry }) => ({
		...entry,
		// The generated index makes the filenames relative to the given directory
		// but we need them to be absolute
		filename: path.join(deviceConfigPriorityDir, filename),
	}));
}

/**
 * @internal
 * Loads the index file to quickly access the device configs.
 * Transparently handles updating the index if necessary
 */
export async function loadDeviceIndexInternal(
	logger?: ConfigLogger,
	externalConfig?: boolean,
): Promise<DeviceConfigIndex> {
	const { devicesDir, indexPath } = getDevicesPaths(
		(externalConfig && externalConfigDir()) || configDir,
	);

	return loadDeviceIndexShared(
		devicesDir,
		indexPath,
		(config) =>
			config.devices.map((dev) => ({
				manufacturerId: formatId(config.manufacturerId.toString(16)),
				manufacturer: config.manufacturer,
				label: config.label,
				productType: formatId(dev.productType),
				productId: formatId(dev.productId),
				firmwareVersion: config.firmwareVersion,
			})),
		logger,
	);
}

/**
 * @internal
 * Loads the full text index file to quickly search the device configs.
 * Transparently handles updating the index if necessary
 */
export async function loadFulltextDeviceIndexInternal(
	logger?: ConfigLogger,
): Promise<FulltextDeviceConfigIndex> {
	// This method is not meant to operate with the external device index!
	return loadDeviceIndexShared(
		embeddedDevicesDir,
		fulltextIndexPath,
		(config) =>
			config.devices.map((dev) => ({
				manufacturerId: formatId(config.manufacturerId.toString(16)),
				manufacturer: config.manufacturer,
				label: config.label,
				description: config.description,
				productType: formatId(dev.productType),
				productId: formatId(dev.productId),
				firmwareVersion: config.firmwareVersion,
				rootDir: embeddedDevicesDir,
			})),
		logger,
	);
}

function isHexKeyWith4Digits(val: any): val is string {
	return typeof val === "string" && hexKeyRegex4Digits.test(val);
}

const firmwareVersionRegex = /^\d{1,3}\.\d{1,3}(\.\d{1,3})?$/;
function isFirmwareVersion(val: any): val is string {
	return (
		typeof val === "string" &&
		firmwareVersionRegex.test(val) &&
		val
			.split(".")
			.map((str) => parseInt(str, 10))
			.every((num) => num >= 0 && num <= 255)
	);
}

/** This class represents a device config entry whose conditional settings have not been evaluated yet */
export class ConditionalDeviceConfig {
	public static async from(
		filename: string,
		isEmbedded: boolean,
		options: {
			rootDir: string;
			relative?: boolean;
		},
	): Promise<ConditionalDeviceConfig> {
		const { relative, rootDir } = options;

		const relativePath = relative
			? path.relative(rootDir, filename).replace(/\\/g, "/")
			: filename;
		const json = await readJsonWithTemplate(filename, options.rootDir);
		return new ConditionalDeviceConfig(relativePath, isEmbedded, json);
	}

	public constructor(
		filename: string,
		isEmbedded: boolean,
		definition: JSONObject,
	) {
		this.filename = filename;
		this.isEmbedded = isEmbedded;

		if (!isHexKeyWith4Digits(definition.manufacturerId)) {
			throwInvalidConfig(
				`device`,
				`packages/config/config/devices/${filename}:
manufacturer id must be a lowercase hexadecimal number with 4 digits`,
			);
		}
		this.manufacturerId = parseInt(definition.manufacturerId, 16);

		for (const prop of ["manufacturer", "label", "description"] as const) {
			this[prop] = parseConditionalPrimitive(
				filename,
				"string",
				prop,
				definition[prop],
			);
		}

		if (
			!isArray(definition.devices) ||
			!(definition.devices as any[]).every(
				(dev: unknown) =>
					isObject(dev) &&
					isHexKeyWith4Digits(dev.productType) &&
					isHexKeyWith4Digits(dev.productId),
			)
		) {
			throwInvalidConfig(
				`device`,
				`packages/config/config/devices/${filename}:
devices is malformed (not an object or type/id that is not a lowercase 4-digit hex key)`,
			);
		}
		this.devices = (definition.devices as any[]).map(
			({ productType, productId }) => ({
				productType: parseInt(productType, 16),
				productId: parseInt(productId, 16),
			}),
		);

		if (
			!isObject(definition.firmwareVersion) ||
			!isFirmwareVersion(definition.firmwareVersion.min) ||
			!isFirmwareVersion(definition.firmwareVersion.max)
		) {
			throwInvalidConfig(
				`device`,
				`packages/config/config/devices/${filename}:
firmwareVersion is malformed or invalid. Must be x.y or x.y.z where x, y, and z are integers between 0 and 255`,
			);
		} else {
			const { min, max } = definition.firmwareVersion;
			this.firmwareVersion = { min, max };
		}

		if (definition.endpoints != undefined) {
			const endpoints = new Map<number, ConditionalEndpointConfig>();
			if (!isObject(definition.endpoints)) {
				throwInvalidConfig(
					`device`,
					`packages/config/config/devices/${filename}:
endpoints is not an object`,
				);
			}
			for (const [key, ep] of Object.entries(definition.endpoints)) {
				if (!/^\d+$/.test(key)) {
					throwInvalidConfig(
						`device`,
						`packages/config/config/devices/${filename}:
found non-numeric endpoint index "${key}" in endpoints`,
					);
				}

				const epIndex = parseInt(key, 10);
				endpoints.set(
					epIndex,
					new ConditionalEndpointConfig(filename, epIndex, ep as any),
				);
			}
			this.endpoints = endpoints;
		}

		if (definition.associations != undefined) {
			const associations = new Map<
				number,
				ConditionalAssociationConfig
			>();
			if (!isObject(definition.associations)) {
				throwInvalidConfig(
					`device`,
					`packages/config/config/devices/${filename}:
associations is not an object`,
				);
			}
			for (const [key, assocDefinition] of Object.entries(
				definition.associations,
			)) {
				if (!/^[1-9][0-9]*$/.test(key)) {
					throwInvalidConfig(
						`device`,
						`packages/config/config/devices/${filename}:
found non-numeric group id "${key}" in associations`,
					);
				}

				const keyNum = parseInt(key, 10);
				associations.set(
					keyNum,
					new ConditionalAssociationConfig(
						filename,
						keyNum,
						assocDefinition as any,
					),
				);
			}
			this.associations = associations;
		}

		if (definition.paramInformation != undefined) {
			const paramInformation = new ObjectKeyMap<
				{ parameter: number; valueBitMask?: number },
				ConditionalParamInformation[]
			>();

			if (isArray(definition.paramInformation)) {
				// Defining paramInformation as an array is the preferred variant now.

				// Check that every param has a param number
				if (
					!definition.paramInformation.every(
						(entry: any) => "#" in entry,
					)
				) {
					throwInvalidConfig(
						`device`,
						`packages/config/config/devices/${filename}: 
required property "#" missing in at least one entry of paramInformation`,
					);
				}

				// And a valid $if condition
				for (const entry of definition.paramInformation) {
					validateCondition(
						filename,
						entry,
						`At least one entry of paramInformation contains an`,
					);
				}

				for (const paramDefinition of definition.paramInformation) {
					const { ["#"]: paramNo, ...defn } = paramDefinition;
					const match = /^(\d+)(?:\[0x([0-9a-fA-F]+)\])?$/.exec(
						paramNo,
					);
					if (!match) {
						throwInvalidConfig(
							`device`,
							`packages/config/config/devices/${filename}: 
found invalid param number "${paramNo}" in paramInformation`,
						);
					}

					const keyNum = parseInt(match[1], 10);
					const bitMask =
						match[2] != undefined
							? parseInt(match[2], 16)
							: undefined;
					const key = { parameter: keyNum, valueBitMask: bitMask };

					if (!paramInformation.has(key))
						paramInformation.set(key, []);
					paramInformation
						.get(key)!
						.push(
							new ConditionalParamInformation(
								this,
								keyNum,
								bitMask,
								defn,
							),
						);
				}
			} else if (
				(process.env.NODE_ENV !== "test" || !!process.env.CI) &&
				isObject(definition.paramInformation)
			) {
				// Prior to v8.1.0, paramDefinition was an object
				// We need to support parsing legacy files because users might have custom configs
				// However, we don't allow this on CI or during tests/lint

				for (const [key, paramDefinition] of Object.entries(
					definition.paramInformation,
				)) {
					const match = /^(\d+)(?:\[0x([0-9a-fA-F]+)\])?$/.exec(key);
					if (!match) {
						throwInvalidConfig(
							`device`,
							`packages/config/config/devices/${filename}:
found invalid param number "${key}" in paramInformation`,
						);
					}

					if (
						!isObject(paramDefinition) &&
						!(
							isArray(paramDefinition) &&
							(paramDefinition as any[]).every((p) => isObject(p))
						)
					) {
						throwInvalidConfig(
							`device`,
							`packages/config/config/devices/${filename}:
paramInformation "${key}" is invalid: Every entry must either be an object or an array of objects!`,
						);
					}

					// Normalize to an array
					const defns: any[] = isArray(paramDefinition)
						? paramDefinition
						: [paramDefinition];

					const keyNum = parseInt(match[1], 10);
					const bitMask =
						match[2] != undefined
							? parseInt(match[2], 16)
							: undefined;
					paramInformation.set(
						{ parameter: keyNum, valueBitMask: bitMask },
						defns.map(
							(def) =>
								new ConditionalParamInformation(
									this,
									keyNum,
									bitMask,
									def,
								),
						),
					);
				}
			} else {
				throwInvalidConfig(
					`device`,
					`packages/config/config/devices/${filename}:
paramInformation must be an array!`,
				);
			}

			this.paramInformation = paramInformation;
		}

		if (definition.proprietary != undefined) {
			if (!isObject(definition.proprietary)) {
				throwInvalidConfig(
					`device`,
					`packages/config/config/devices/${filename}:
proprietary is not an object`,
				);
			}
			this.proprietary = definition.proprietary;
		}

		if (definition.compat != undefined) {
			if (
				isArray(definition.compat) &&
				definition.compat.every((item: any) => isObject(item))
			) {
				// Make sure all conditions are valid
				for (const entry of definition.compat) {
					validateCondition(
						filename,
						entry,
						`At least one entry of compat contains an`,
					);
				}

				this.compat = definition.compat.map(
					(item: any) => new ConditionalCompatConfig(filename, item),
				);
			} else if (isObject(definition.compat)) {
				this.compat = new ConditionalCompatConfig(
					filename,
					definition.compat,
				);
			} else {
				throwInvalidConfig(
					`device`,
					`packages/config/config/devices/${filename}:
compat must be an object or any array of conditional objects`,
				);
			}
		}

		if (definition.metadata != undefined) {
			if (!isObject(definition.metadata)) {
				throwInvalidConfig(
					`device`,
					`packages/config/config/devices/${filename}:
metadata is not an object`,
				);
			}
			this.metadata = new ConditionalDeviceMetadata(
				filename,
				definition.metadata,
			);
		}
	}

	public readonly filename: string;

	public readonly manufacturer!: ConditionalPrimitive<string>;
	public readonly manufacturerId: number;
	public readonly label!: ConditionalPrimitive<string>;
	public readonly description!: ConditionalPrimitive<string>;
	public readonly devices: readonly {
		productType: number;
		productId: number;
	}[];
	public readonly firmwareVersion: FirmwareVersionRange;
	public readonly endpoints?: ReadonlyMap<number, ConditionalEndpointConfig>;
	public readonly associations?: ReadonlyMap<
		number,
		ConditionalAssociationConfig
	>;
	public readonly paramInformation?: ConditionalParamInfoMap;
	/**
	 * Contains manufacturer-specific support information for the
	 * ManufacturerProprietary CC
	 */
	public readonly proprietary?: Record<string, unknown>;
	/** Contains compatibility options */
	public readonly compat?:
		| ConditionalCompatConfig
		| ConditionalCompatConfig[];
	/** Contains instructions and other metadata for the device */
	public readonly metadata?: ConditionalDeviceMetadata;

	/** Whether this is an embedded configuration or not */
	public readonly isEmbedded: boolean;

	public evaluate(deviceId?: DeviceID): DeviceConfig {
		return new DeviceConfig(
			this.filename,
			this.isEmbedded,
			evaluateDeep(this.manufacturer, deviceId),
			this.manufacturerId,
			evaluateDeep(this.label, deviceId),
			evaluateDeep(this.description, deviceId),
			this.devices,
			this.firmwareVersion,
			evaluateDeep(this.endpoints, deviceId),
			evaluateDeep(this.associations, deviceId),
			evaluateDeep(this.paramInformation, deviceId),
			this.proprietary,
			evaluateDeep(this.compat, deviceId),
			evaluateDeep(this.metadata, deviceId),
		);
	}
}

export class DeviceConfig {
	public static async from(
		filename: string,
		isEmbedded: boolean,
		options: {
			rootDir: string;
			relative?: boolean;
			deviceId?: DeviceID;
		},
	): Promise<DeviceConfig> {
		const ret = await ConditionalDeviceConfig.from(
			filename,
			isEmbedded,
			options,
		);
		return ret.evaluate(options.deviceId);
	}

	public constructor(
		public readonly filename: string,
		/** Whether this is an embedded configuration or not */
		public readonly isEmbedded: boolean,

		public readonly manufacturer: string,
		public readonly manufacturerId: number,
		public readonly label: string,
		public readonly description: string,
		public readonly devices: readonly {
			productType: number;
			productId: number;
		}[],
		public readonly firmwareVersion: FirmwareVersionRange,
		public readonly endpoints?: ReadonlyMap<number, EndpointConfig>,
		public readonly associations?: ReadonlyMap<number, AssociationConfig>,
		public readonly paramInformation?: ParamInfoMap,
		/**
		 * Contains manufacturer-specific support information for the
		 * ManufacturerProprietary CC
		 */
		public readonly proprietary?: Record<string, unknown>,
		/** Contains compatibility options */
		public readonly compat?: CompatConfig,
		/** Contains instructions and other metadata for the device */
		public readonly metadata?: DeviceMetadata,
	) {}

	/** Returns the association config for a given endpoint */
	public getAssociationConfigForEndpoint(
		endpointIndex: number,
		group: number,
	): AssociationConfig | undefined {
		if (endpointIndex === 0) {
			// The root endpoint's associations may be configured separately or as part of "endpoints"
			return (
				this.associations?.get(group) ??
				this.endpoints?.get(0)?.associations?.get(group)
			);
		} else {
			// The other endpoints can only have a configuration as part of "endpoints"
			return this.endpoints?.get(endpointIndex)?.associations?.get(group);
		}
	}
}