(function(window) {
    function isPromise(o) {
        return o instanceof Promise
    }

    function flattenPromise (obj) {
        if (obj instanceof Promise) {
            return Promise.resolve(obj);
        }

        if (obj instanceof Array) {
            return new Promise(function (resolve) {
                var promises = obj.map(function (o) {
                    return flattenPromise(o);
                });

                return Promise.all(promises).then(function (res) {
                    for (var i = 0; i < obj.length; i++) {
                        obj[i] = res[i];
                    }
                    resolve(obj);
                });
            });
        }
        
        if (obj instanceof Object) {
            return new Promise(function (resolve) {
                var keys = Object.keys(obj);
                var promises = keys.map(function (key) {
                    return flattenPromise(obj[key]);
                });

                return Promise.all(promises).then(function (res) {
                    for (var i = 0; i < keys.length; i++) {
                        obj[keys[i]] = res[i];
                    }
                    resolve(obj);
                });
            });
        }

        return Promise.resolve(obj);
    };

    var ethMethods = function () {
        var blockCall = function (args) {
            return typeof args[0] === "string" ? "blockByHash" : "blockByNumber";
        };

        var transactionCall = function (args) {
            return typeof args[0] === "string" ? 'transactionByHash' : 'transactonByNumber';   
        };

        var uncleCall = function (args) {
            return typeof args[0] === "string" ? 'uncleByHash' : 'uncleByNumber';       
        };

        var methods = [
        { name: 'balanceAt', call: 'balanceAt' },
        { name: 'stateAt', call: 'stateAt' },
        { name: 'countAt', call: 'countAt'},
        { name: 'codeAt', call: 'codeAt' },
        { name: 'transact', call: 'transact' },
        { name: 'call', call: 'call' },
        { name: 'block', call: blockCall },
        { name: 'transaction', call: transactionCall },
        { name: 'uncle', call: uncleCall },
        { name: 'compile', call: 'compile' }
        ];
        return methods;
    };

    var ethProperties = function () {
        return [
        { name: 'coinbase', getter: 'coinbase', setter: 'setCoinbase' },
        { name: 'listening', getter: 'listening', setter: 'setListening' },
        { name: 'mining', getter: 'mining', setter: 'setMining' },
        { name: 'gasPrice', getter: 'gasPrice' },
        { name: 'accounts', getter: 'accounts' },
        { name: 'peerCount', getter: 'peerCount' },
        { name: 'defaultBlock', getter: 'defaultBlock', setter: 'setDefaultBlock' },
        { name: 'number', getter: 'number'}
        ];
    };

    var dbMethods = function () {
        return [
        { name: 'put', call: 'put' },
        { name: 'get', call: 'get' },
        { name: 'putString', call: 'putString' },
        { name: 'getString', call: 'getString' }
        ];
    };

    var shhMethods = function () {
        return [
        { name: 'post', call: 'post' },
        { name: 'newIdentity', call: 'newIdentity' },
        { name: 'haveIdentity', call: 'haveIdentity' },
        { name: 'newGroup', call: 'newGroup' },
        { name: 'addToGroup', call: 'addToGroup' }
        ];
    };

    var ethWatchMethods = function () {
        var newFilter = function (args) {
            return typeof args[0] === 'string' ? 'newFilterString' : 'newFilter';
        };

        return [
        { name: 'newFilter', call: newFilter },
        { name: 'uninstallFilter', call: 'uninstallFilter' },
        { name: 'changed', call: 'changed' },
        { name: 'getMessages', call: 'getMessages' }
        ];
    };

    var shhWatchMethods = function () {
        return [
        { name: 'newFilter', call: 'shhNewFilter' },
        { name: 'uninstallFilter', call: 'shhUninstallFilter' },
        { name: 'changed', call: 'shhChanged' },
        { name: 'getMessage', call: 'shhGetMessages' }
        ];
    };

    var setupMethods = function (obj, methods) {
        methods.forEach(function (method) {
            obj[method.name] = function () {
                return flattenPromise(Array.prototype.slice.call(arguments)).then(function (args) {
                    var call = typeof method.call === "function" ? method.call(args) : method.call; 
                    return {call: call, args: args};
                }).then(function (request) {
                    return new Promise(function (resolve, reject) {
                        web3.provider.send(request, function (result) {
                            if (result) {
                                resolve(result);
                            } else {
                                reject(result);
                            }
                        });
                    });
                }).catch(function( err) {
                    console.error(err);
                });
            };
        });
    };

    var setupProperties = function (obj, properties) {
        properties.forEach(function (property) {
            var proto = {};
            proto.get = function () {
                return new Promise(function(resolve, reject) {
                    web3.provider.send({call: property.getter}, function(result) {
                        resolve(result);
                    });
                });
            };
            if (property.setter) {
                proto.set = function (val) {
                    return flattenPromise([val]).then(function (args) {
                        return new Promise(function (resolve) {
                            web3.provider.send({call: property.setter, args: args}, function (result) {
                                if (result) {
                                    resolve(result);
                                } else {
                                    reject(result);
                                }
                            });
                        });
                    }).catch(function (err) {
                        console.error(err);
                    });
                }
            }
            Object.defineProperty(obj, property.name, proto);
        });
    };
    
    var web3 = {
        _callbacks: {},
        _events: {},
        providers: {},
        toHex: function(str) {
            var hex = "";
            for(var i = 0; i < str.length; i++) {
                var n = str.charCodeAt(i).toString(16);
                hex += n.length < 2 ? '0' + n : n;
            }

            return hex;
        },

        toAscii: function(hex) {
            // Find termination
            var str = "";
            var i = 0, l = hex.length;
            for(; i < l; i+=2) {
                var code = hex.charCodeAt(i)
                if(code == 0) {
                    break;
                }

                str += String.fromCharCode(parseInt(hex.substr(i, 2), 16));
            }

            return str;
        },

        toDecimal: function (val) {
            return parseInt(val, 16);         
        },

        fromAscii: function(str, pad) {
            if(pad === undefined) {
                pad = 32
            }

            var hex = this.toHex(str);

            while(hex.length < pad*2)
                hex += "00";

            return hex
        },

        eth: {
            prototype: Object(),
            watch: function (params) {
                return new Filter(params, ethWatch);
            },
        },

        db: {
            prototype: Object()
        },

        shh: {
            prototype: Object(),
            watch: function (params) {
                return new Filter(params, shhWatch);
            }
        },

        on: function(event, cb) {
            if(web3._events[event] === undefined) {
                web3._events[event] = [];
            }

            web3._events[event].push(cb);

            return this
        },

        off: function(event, cb) {
            if(web3._events[event] !== undefined) {
                var callbacks = web3._events[event];
                for(var i = 0; i < callbacks.length; i++) {
                    if(callbacks[i] === cb) {
                        delete callbacks[i];
                    }
                }
            }

            return this
        },

        trigger: function(event, data) {
            var callbacks = web3._events[event];
            if(callbacks !== undefined) {
                for(var i = 0; i < callbacks.length; i++) {
                    // Figure out whether the returned data was an array
                    // array means multiple return arguments (multiple params)
                    if(data instanceof Array) {
                        callbacks[i].apply(this, data);
                    } else {
                        callbacks[i].call(this, undefined, data);
                    }
                }
            }
        },
    };

    var eth = web3.eth;
    setupMethods(eth, ethMethods());
    setupProperties(eth, ethProperties());
    setupMethods(web3.db, dbMethods());
    setupMethods(web3.shh, shhMethods());

    var ethWatch = {};
    setupMethods(ethWatch, ethWatchMethods());
    var shhWatch = {};
    setupMethods(shhWatch, shhWatchMethods());

    var ProviderManager = function() {
        this.queued = [];
        this.polls = [];
        this.ready = false;
        this.provider = undefined;
        this.id = 1;

        var self = this;
        var poll = function () {
            if (self.provider && self.provider.poll) {
                self.polls.forEach(function (data) {
                    data.data._id = self.id; 
                    self.id++;
                    self.provider.poll(data.data, data.id);
                });
            }
            setTimeout(poll, 12000);
        };
        poll();
    };

    ProviderManager.prototype.send = function(data, cb) {
        data._id = this.id;
        if(cb) {
            web3._callbacks[data._id] = cb;
        }

        if(data.args === undefined) {
            data.args = [];
        }

        this.id++;

        if(this.provider !== undefined) {
            this.provider.send(data);
        } else {
            console.warn("provider is not set");
            this.queued.push(data);
        }
    };

    ProviderManager.prototype.set = function(provider) {
        if(this.provider !== undefined && this.provider.unload !== undefined) {
            this.provider.unload();
        }

        this.provider = provider;
        this.ready = true;
    };

    ProviderManager.prototype.sendQueued = function() {
        for(var i = 0; this.queued.length; i++) {
            // Resend
            this.send(this.queued[i]);
        }
    };

    ProviderManager.prototype.installed = function() {
        return this.provider !== undefined;
    };

    ProviderManager.prototype.startPolling = function (data, pollId) {
        if (!this.provider || !this.provider.poll) {
            return;
        }
        this.polls.push({data: data, id: pollId});
    };

    ProviderManager.prototype.stopPolling = function (pollId) {
        for (var i = this.polls.length; i--;) {
            var poll = this.polls[i];
            if (poll.id === pollId) {
                this.polls.splice(i, 1);
            }
        }
    };

    web3.provider = new ProviderManager();

    web3.setProvider = function(provider) {
        provider.onmessage = messageHandler;
        web3.provider.set(provider);
        web3.provider.sendQueued();
    };

    var filters = [];
    var Filter = function(options, impl) {
        filters.push(this);

        this.impl = impl;
        this.callbacks = [];

        var self = this; // Cheaper than binding
        this.promise = impl.newFilter(options); 
        this.promise.then(function (id) {
            self.id = id;
            web3.provider.startPolling({call: 'changed', args: [id]}, id);
        });
    };

    Filter.prototype.changed = function(callback) {
        var self = this;
        this.promise.then(function(id) {
            self.callbacks.push(callback);
        });
    };

    Filter.prototype.trigger = function(messages, id) {
        if(id == this.id) {
            for(var i = 0; i < this.callbacks.length; i++) {
                this.callbacks[i].call(this, messages);
            }
        }
    };

    Filter.prototype.uninstall = function() {
        var self = this;
        this.promise.then(function (id) {
            self.impl.uninstallFilter(id);
            web3.provider.stopPolling(id);
        });
    };

    Filter.prototype.messages = function() {
        var self = this;    
        return this.promise.then(function (id) {
            return self.impl.getMessages(id);
        });
    };

    // Register to the messages callback. "messages" will be emitted when new messages
    // from the client have been created.
    web3.on("messages", function(messages, id) {
        for(var i = 0; i < filters.length; i++) {
            filters[i].trigger(messages, id);
        }
    });

    function messageHandler(data) {
        if(data._event !== undefined) {
            web3.trigger(data._event, data.data);
        } else {
            if(data._id) {
                var cb = web3._callbacks[data._id];
                if(cb) {
                    cb.call(this, data.data)

                    // Remove the "trigger" callback
                    delete web3._callbacks[data._id];
                }
            }
        }
    }

    /*
    // Install default provider
    if(!web3.provider.installed()) {
        var sock = new web3.WebSocket("ws://localhost:40404/eth");

        web3.setProvider(sock);
    }
    */

    window.web3 = web3;

})(this);