/*
    This file is part of ethereum.js.

    ethereum.js is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    ethereum.js is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with ethereum.js.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @file main.js
 * @authors:
 *   Jeffrey Wilcke <jeff@ethdev.com>
 *   Marek Kotewicz <marek@ethdev.com>
 *   Marian Oancea <marian@ethdev.com>
 * @date 2014
 */

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" ? "eth_blockByHash" : "eth_blockByNumber";
    };

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

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

    var methods = [
    { name: 'balanceAt', call: 'eth_balanceAt' },
    { name: 'stateAt', call: 'eth_stateAt' },
    { name: 'countAt', call: 'eth_countAt'},
    { name: 'codeAt', call: 'eth_codeAt' },
    { name: 'transact', call: 'eth_transact' },
    { name: 'call', call: 'eth_call' },
    { name: 'block', call: blockCall },
    { name: 'transaction', call: transactionCall },
    { name: 'uncle', call: uncleCall },
    { name: 'compile', call: 'eth_compile' },
    { name: 'lll', call: 'eth_lll' }
    ];
    return methods;
};

var ethProperties = function () {
    return [
    { name: 'coinbase', getter: 'eth_coinbase', setter: 'eth_setCoinbase' },
    { name: 'listening', getter: 'eth_listening', setter: 'eth_setListening' },
    { name: 'mining', getter: 'eth_mining', setter: 'eth_setMining' },
    { name: 'gasPrice', getter: 'eth_gasPrice' },
    { name: 'account', getter: 'eth_account' },
    { name: 'accounts', getter: 'eth_accounts' },
    { name: 'peerCount', getter: 'eth_peerCount' },
    { name: 'defaultBlock', getter: 'eth_defaultBlock', setter: 'eth_setDefaultBlock' },
    { name: 'number', getter: 'eth_number'}
    ];
};

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

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

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

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

var shhWatchMethods = function () {
    return [
    { name: 'newFilter', call: 'shh_newFilter' },
    { name: 'uninstallFilter', call: 'shh_uninstallFilter' },
    { name: 'getMessage', call: 'shh_getMessages' }
    ];
};

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 (err, result) {
                        if (!err) {
                            resolve(result);
                            return;
                        }
                        reject(err);
                    });
                });
            }).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(err, result) {
                    if (!err) {
                        resolve(result);
                        return;
                    }
                    reject(err);
                });
            });
        };
        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 (err, result) {
                            if (!err) {
                                resolve(result);
                                return;
                            }
                            reject(err);
                        });
                    });
                }).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;
        if (hex.substring(0, 2) === '0x')
            i = 2;
        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) {
        pad = pad === undefined ? 32 : pad;
        var hex = this.toHex(str);
        while(hex.length < pad*2)
            hex += "00";
        return "0x" + hex;
    },

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

    db: {
        prototype: Object() // jshint ignore:line
    },

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

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

        web3._events[event][id] = cb;
        return this;
    },

    off: function(event, id) {
        if(web3._events[event] !== undefined) {
            delete web3._events[event][id];
        }

        return this;
    },

    trigger: function(event, id, data) {
        var callbacks = web3._events[event];
        if (!callbacks || !callbacks[id]) {
            return;
        }
        var cb = callbacks[id];
        cb(data);
    }
};

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

var ethWatch = {
    changed: 'eth_changed'
};
setupMethods(ethWatch, ethWatchMethods());
var shhWatch = {
    changed: 'shh_changed'
};
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;
    }

    data.args = 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 Filter = function(options, impl) {
    this.impl = impl;
    this.callbacks = [];

    var self = this;
    this.promise = impl.newFilter(options);
    this.promise.then(function (id) {
        self.id = id;
        web3.on(impl.changed, id, self.trigger.bind(self));
        web3.provider.startPolling({call: impl.changed, args: [id]}, id);
    });
};

Filter.prototype.arrived = function(callback) {
    this.changed(callback);
};

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

Filter.prototype.trigger = function(messages) {
    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);
        web3.off(impl.changed, id);
    });
};

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

function messageHandler(data) {
    if(data._event !== undefined) {
        web3.trigger(data._event, data._id, data.data);
        return;
    }

    if(data._id) {
        var cb = web3._callbacks[data._id];
        if (cb) {
            cb.call(this, data.error, data.data);
            delete web3._callbacks[data._id];
        }
    }
}

module.exports = web3;