"use strict";

let _permanentCensorErrors = false;
let _censorErrors = false;

const LogLevels: { [ name: string ]: number } = { debug: 1, "default": 2, info: 2, warn: 3, error: 4, off: 5 };
let LogLevel = LogLevels["default"];

import { version } from "./_version";

let _globalLogger: Logger = null;

export type LogLevel = "DEBUG" | "INFO" | "WARNING" | "ERROR" | "OFF";

function _checkNormalize(): string {
    try {
        let missing: Array<string> = [ ];

        // Make sure all forms of normalization are supported
        ["NFD", "NFC", "NFKD", "NFKC"].forEach((form) => {
            try {
                if ("test".normalize(form) !== "test") {
                    throw new Error("bad normalize");
                };
            } catch(error) {
                missing.push(form);
            }
        });

        if (missing.length) {
            throw new Error("missing " + missing.join(", "));
        }

        if (String.fromCharCode(0xe9).normalize("NFD") !== String.fromCharCode(0x65, 0x0301)) {
            throw new Error("broken implementation")
        }
    } catch (error) {
        return error.message;
    }

    return null;
}

let _normalizeError = _checkNormalize();

export class Logger {
    readonly version: string;

    static errors = {

        ///////////////////
        // Generic Errors

        // Unknown Error
        UNKNOWN_ERROR: "UNKNOWN_ERROR",

        // Not Implemented
        NOT_IMPLEMENTED: "NOT_IMPLEMENTED",

        // Unsupported Operation
        //   - operation
        UNSUPPORTED_OPERATION: "UNSUPPORTED_OPERATION",

        // Network Error (i.e. Ethereum Network, such as an invalid chain ID)
        NETWORK_ERROR: "NETWORK_ERROR",

        // Some sort of bad response from the server
        SERVER_ERROR: "SERVER_ERROR",

        // Timeout
        TIMEOUT: "TIMEOUT",

        ///////////////////
        // Operational  Errors

        // Buffer Overrun
        BUFFER_OVERRUN: "BUFFER_OVERRUN",

        // Numeric Fault
        //   - operation: the operation being executed
        //   - fault: the reason this faulted
        NUMERIC_FAULT: "NUMERIC_FAULT",


        ///////////////////
        // Argument Errors

        // Missing new operator to an object
        //  - name: The name of the class
        MISSING_NEW: "MISSING_NEW",

        // Invalid argument (e.g. value is incompatible with type) to a function:
        //   - argument: The argument name that was invalid
        //   - value: The value of the argument
        INVALID_ARGUMENT: "INVALID_ARGUMENT",

        // Missing argument to a function:
        //   - count: The number of arguments received
        //   - expectedCount: The number of arguments expected
        MISSING_ARGUMENT: "MISSING_ARGUMENT",

        // Too many arguments
        //   - count: The number of arguments received
        //   - expectedCount: The number of arguments expected
        UNEXPECTED_ARGUMENT: "UNEXPECTED_ARGUMENT",


        ///////////////////
        // Blockchain Errors

        // Call exception
        //  - transaction: the transaction
        //  - address?: the contract address
        //  - args?: The arguments passed into the function
        //  - method?: The Solidity method signature
        //  - errorSignature?: The EIP848 error signature
        //  - errorArgs?: The EIP848 error parameters
        //  - reason: The reason (only for EIP848 "Error(string)")
        CALL_EXCEPTION: "CALL_EXCEPTION",

        // Insufficien funds (< value + gasLimit * gasPrice)
        //   - transaction: the transaction attempted
        INSUFFICIENT_FUNDS: "INSUFFICIENT_FUNDS",

        // Nonce has already been used
        //   - transaction: the transaction attempted
        NONCE_EXPIRED: "NONCE_EXPIRED",

        // The replacement fee for the transaction is too low
        //   - transaction: the transaction attempted
        REPLACEMENT_UNDERPRICED: "REPLACEMENT_UNDERPRICED",

        // The gas limit could not be estimated
        //   - transaction: the transaction passed to estimateGas
        UNPREDICTABLE_GAS_LIMIT: "UNPREDICTABLE_GAS_LIMIT",
    };

    static levels: { [ name: string ]: LogLevel } = {
        DEBUG: "DEBUG",
        INFO: "INFO",
        WARNING: "WARNING",
        ERROR: "ERROR",
        OFF: "OFF"
    };

    constructor(version: string) {
        Object.defineProperty(this, "version", {
            enumerable: true,
            value: version,
            writable: false
        });
    }

    setLogLevel(logLevel: LogLevel): void {
        let level = LogLevels[logLevel];
        if (level == null) {
            this.warn("invalid log level - " + logLevel);
            return;
        }
        LogLevel = level;
    }

    _log(logLevel: LogLevel, args: Array<any>): void {
        if (LogLevel > LogLevels[logLevel]) { return; }
        console.log.apply(console, args);
    }

    debug(...args: Array<any>): void {
        this._log(Logger.levels.DEBUG, args);
    }

    info(...args: Array<any>): void {
        this._log(Logger.levels.INFO, args);
    }

    warn(...args: Array<any>): void {
        this._log(Logger.levels.WARNING, args);
    }

    makeError(message: string, code?: string, params?: any): Error {
        if (_censorErrors) {
            return new Error("unknown error");
        }

        if (!code) { code = Logger.errors.UNKNOWN_ERROR; }
        if (!params) { params = {}; }

        let messageDetails: Array<string> = [];
        Object.keys(params).forEach((key) => {
            try {
                messageDetails.push(key + "=" + JSON.stringify(params[key]));
            } catch (error) {
                messageDetails.push(key + "=" + JSON.stringify(params[key].toString()));
            }
        });
        messageDetails.push("version=" + this.version);

        let reason = message;
        if (messageDetails.length) {
            message += " (" + messageDetails.join(", ") + ")";
        }

        // @TODO: Any??
        let error: any = new Error(message);
        error.reason = reason;
        error.code = code

        Object.keys(params).forEach(function(key) {
            error[key] = params[key];
        });

        return error;
    }

    throwError(message: string, code?: string, params?: any): never {
        throw this.makeError(message, code, params);
    }

    throwArgumentError(message: string, name: string, value: any): never {
        return this.throwError(message, Logger.errors.INVALID_ARGUMENT, {
            argument: name,
            value: value
        });
    }

    checkNormalize(message?: string): void {
        if (message == null) { message = "platform missing String.prototype.normalize"; }
        if (_normalizeError) {
            this.throwError("platform missing String.prototype.normalize", Logger.errors.UNSUPPORTED_OPERATION, {
                operation: "String.prototype.normalize", form: _normalizeError
            });
        }
    }

    checkSafeUint53(value: number, message?: string): void {
        if (typeof(value) !== "number") { return; }

        if (message == null) { message = "value not safe"; }

        if (value < 0 || value >= 0x1fffffffffffff) {
            this.throwError(message, Logger.errors.NUMERIC_FAULT, {
                operation: "checkSafeInteger",
                fault: "out-of-safe-range",
                value: value
            });
        }

        if (value % 1) {
            this.throwError(message, Logger.errors.NUMERIC_FAULT, {
                operation: "checkSafeInteger",
                fault: "non-integer",
                value: value
            });
        }
    }

    checkArgumentCount(count: number, expectedCount: number, message?: string): void {
        if (message) {
            message = ": " + message;
        } else {
            message = "";
        }

        if (count < expectedCount) {
            this.throwError("missing argument" + message, Logger.errors.MISSING_ARGUMENT, {
                count: count,
                expectedCount: expectedCount
            });
        }

        if (count > expectedCount) {
            this.throwError("too many arguments" + message, Logger.errors.UNEXPECTED_ARGUMENT, {
                count: count,
                expectedCount: expectedCount
            });
        }
    }

    checkNew(target: any, kind: any): void {
        if (target === Object || target == null) {
            this.throwError("missing new", Logger.errors.MISSING_NEW, { name: kind.name });
        }
    }

    checkAbstract(target: any, kind: any): void {
        if (target === kind) {
            this.throwError(
                "cannot instantiate abstract class " + JSON.stringify(kind.name) + " directly; use a sub-class",
                Logger.errors.UNSUPPORTED_OPERATION,
                { name: target.name, operation: "new" }
            );
        } else if (target === Object || target == null) {
            this.throwError("missing new", Logger.errors.MISSING_NEW, { name: kind.name });
        }
    }

    static globalLogger(): Logger {
        if (!_globalLogger) { _globalLogger = new Logger(version); }
        return _globalLogger;
    }

    static setCensorship(censorship: boolean, permanent?: boolean): void {
        if (_permanentCensorErrors) {
            if (!censorship) { return; }
            this.globalLogger().throwError("error censorship permanent", Logger.errors.UNSUPPORTED_OPERATION, {
                operation: "setCensorship"
            });
        }

        _censorErrors = !!censorship;
        _permanentCensorErrors = !!permanent;
    }
}