var q = require('q');
var HTTP = require('q-io/http');
var URL = require('url');
var _ = require('underscore');
var util = require('util');

var designDocs = require('./couchdb-design-docs');

module.exports = function(couchDbURL) {

    function stringifyFunctions(value) {
        if ( value === null ) {
            return null;
        } else if ( _.isArray(value) ) {
            return value;
        } else if ( _.isFunction(value) ) {
            return value.toString();
        } else if ( _.isObject(value) ) {
            value = _.clone(value);
            _.each(value, function(propValue, propName){
                value[propName] = stringifyFunctions(propValue);
            });
            return value;
        } else {
            return value;
        }
    }

    function request(method,path,content) {
        var url = couchDbURL+path;
        var parsedURL = URL.parse(url);
        var options = {
            url: url,
            method: method,
            headers: {
                'content-type': 'application/json; charset=utf-8',
                'accept': 'application/json'
            },
            body: {
                forEach: function(callback) {
                    callback(JSON.stringify(content || {}));
                }
            }
        };
        // because q-io doesn't support auth properly, we have to
        // build the f*ing wheel again.
        if ( parsedURL.auth ) {
            var auth = new Buffer(parsedURL.auth).toString("base64");
            options.headers.authorization = 'Basic '+auth;
        }
        return HTTP.request(options)
        .then(function(res){
            return res.body.read().then(function(content){
                return JSON.parse(content.toString() || "{}");
            });
        },function(res){
            return res.body.read().then(function(error){
                console.warn(error); // q.all doesn't do errors, so let's show them here
                return JSON.parse(error.toString() || "{}");
            });
        });
    }

    console.log("Configuring CouchDB for QED");
    console.log("Checking CouchDB version");
    return request('GET','')
    .then(function(res){
        if (res.version !== "1.2.0" ) {
            console.log("Found "+res.version+", only tested with CouchDB 1.2.0");
        } else {
            console.log("CouchDB 1.2.0 found");
        }
    }).then(function(res){
        console.log("Checking database 'qed'");
        return request('GET','qed')
        .then(function(res){
            console.log("Database 'qed' found.");
        },function(err){
            console.log("Creating database 'qed'");
            return request('PUT','qed');
        });
    }).then(function(){
        console.log("Putting documents in database.");
        designDocs = stringifyFunctions(designDocs);
        return q.all(_.map(designDocs, function(doc,docUrl){
            var configAction = doc.__configAction;
            delete doc.__configAction;
            switch (configAction) {
                case "ignore":
                    console.log(docUrl+" ignored.");
                break;
                case "update":
                    console.log(docUrl+" updating.");
                    return request('GET',docUrl)
                    .then(function(oldDoc){
                        _.extend(oldDoc,doc);
                        return request('PUT',docUrl,oldDoc);
                    },function(){
                        return request('PUT',docUrl,doc);
                    });
                break;
                case "replace":
                default:
                    console.log(docUrl+" replacing.");
                    return request('GET',docUrl)
                    .then(function(oldDoc){
                        _.extend(doc,_.pick(oldDoc,'_id','_rev'));
                        return request('PUT',docUrl,doc);
                    },function(){
                        return request('PUT',docUrl,doc);
                    });
                break;
            }
        }));
    }).then(function(){
        console.log("Done!");
    },function(err){
        console.error("ERROR",err,err.stack);
    });

};