'use strict';

var validator = new (require('jsonschema').Validator)();
var recase = require('recase').create({});

var portSchema = { type: 'number', minimum: 1, maximum: 65535 };

var moduleSchemas = {
  // the proxy module is common to basically all categories.
  proxy: {
    type: 'object'
  , oneOf: [
      { required: [ 'address' ] }
    , { required: [ 'port' ] }
    ]
  , properties: {
      address: { type: 'string' }
    , host:    { type: 'string' }
    , port:    portSchema
    }
  }

  // redirect and static modules are for HTTP
, redirect: {
    type: 'object'
  , required: [ 'to', 'from' ]
  , properties: {
      to:     { type: 'string'}
    , from:   { type: 'string'}
    , status: { type: 'integer', minimum: 1, maximum: 999 }
  , }
  }
, static: {
    type: 'object'
  , required: [ 'root' ]
  , properties: {
      root: { type: 'string' }
    }
  }

  // the acme module is for TLS
, acme: {
    type: 'object'
  , required: [ 'email' ]
  , properties: {
      email:         { type: 'string' }
    , server:        { type: 'string' }
    , challengeType: { type: 'string' }
    }
  }
};
// forward is basically the name for the TCP proxy
moduleSchemas.forward = JSON.parse(JSON.stringify(moduleSchemas.proxy));
moduleSchemas.forward.required = [ 'ports' ];
moduleSchemas.forward.properties.ports = { type: 'array', items: portSchema };

Object.keys(moduleSchemas).forEach(function (name) {
  var schema = moduleSchemas[name];
  schema.id = '/modules/'+name;
  schema.required = ['id', 'type'].concat(schema.required || []);
  schema.properties.id   = { type: 'string' };
  schema.properties.type = { type: 'string', const: name };
  validator.addSchema(schema, schema.id);
});

function addDomainsSchema(base, modList) {
  var modSchemas = modList.map(function (name) {
    return { '$ref': '/modules/'+name };
  });

  base.required = [ 'modules', 'domains' ].concat(base.required || []);
  base.properties.modules = {
    type: 'array'
  , items: {
      type: 'object'
    , required: [ 'domains' ]
    , properties: {
        domains: { type: 'array', items: { type: 'string' }, minLength: 1}
      }
    , oneOf: modSchemas
    }
  };
  base.properties.domains = {
    type: 'array'
  , items: {
      type: 'object'
    , required: [ 'id', 'names', ]
    , properties: {
        id:      { type: 'string' }
      , names:   { type: 'array', items: { type: 'string' }, minLength: 1}
      , modules: { type: 'array', items: { oneOf: modSchemas }}
      }
    }
  };
}

var httpSchema = {
  type: 'object'
, properties: {
    // These properties should be snake_case to match the API and config format
    primary_domain: { type: 'string' }
  , allow_insecure: { type: 'boolean' }
  , trust_proxy:    { type: 'boolean' }
, }
};
addDomainsSchema(httpSchema, ['proxy', 'static', 'redirect']);

var tlsSchema = {
  type: 'object'
, properties: {
    acme: {
      type: 'object'
      // These properties should be snake_case to match the API and config format
    , required: [ 'email', 'approved_domains' ]
    , properties: {
        email:            { type: 'string' }
      , server:           { type: 'string' }
      , challenge_type:   { type: 'string' }
      , approved_domains: { type: 'array', items: { type: 'string' }, minLength: 1}
      }
    }
  }
};
addDomainsSchema(tlsSchema, ['proxy', 'acme']);

var tcpSchema = {
  type: 'object'
, required: [ 'bind' ]
, properties: {
    bind:    { type: 'array', items: portSchema, minLength: 1 }
  , modules: { type: 'array', items: { '$ref': '/modules/forward' }}
  }
};

var dnsSchema = {
  type: 'object'
, properties: {
    bind:    { type: 'array', items: portSchema }
  , modules: { type: 'array', items: { '$ref': '/modules/proxy' }}
  }
};

var mdnsSchema = {
  type: 'object'
, required: [ 'port', 'broadcast', 'ttl' ]
, properties: {
    port:      portSchema
  , broadcast: { type: 'string' }
  , ttl:       { type: 'integer', minimum: 0, maximum: 2147483647 }
  }
};

var ddnsSchema = {
  type: 'object'
, properties: {
    enabled: { type: 'boolean' }
  }
};
var socks5Schema = {
  type: 'object'
, properties: {
    enabled: { type: 'boolean' }
  , port:    portSchema
  }
};
var deviceSchema = {
  type: 'object'
, properties: {
    hostname: { type: 'string' }
  }
};

var mainSchema = {
  type: 'object'
, required: [ 'http', 'tls', 'tcp', 'dns', 'mdns', 'ddns' ]
, properties: {
    http:   httpSchema
  , tls:    tlsSchema
  , tcp:    tcpSchema
  , dns:    dnsSchema
  , mdns:   mdnsSchema
  , ddns:   ddnsSchema
  , socks5: socks5Schema
  , device: deviceSchema
  }
, additionalProperties: false
};

function validate(config) {
  return validator.validate(recase.snakeCopy(config), mainSchema).errors;
}
module.exports.validate = validate;


class ModuleList extends Array {
  constructor(rawList) {
    super();
    if (Array.isArray(rawList)) {
      Object.assign(this, JSON.parse(JSON.stringify(rawList)));
    }
  }

  find(id) {
    return Array.prototype.find.call(this, function (mod) {
      return mod.id === id;
    });
  }
  add(mod) {
    if (!mod.type) {
      throw new Error("module must have a 'type' defined");
    }
    if (!moduleSchemas[mod.type]) {
      throw new Error("invalid module type '"+mod.type+"'");
    }

    mod.id = require('crypto').randomBytes(4).toString('hex');
    this.push(mod);
  }
}
class DomainList extends Array {
  constructor(rawList) {
    super();
    if (Array.isArray(rawList)) {
      Object.assign(this, JSON.parse(JSON.stringify(rawList)));
    }
    this.forEach(function (dom) {
      dom.modules = new ModuleList(dom.modules);
    });
  }

  find(id) {
    return Array.prototype.find.call(this, function (dom) {
      return dom.id === id;
    });
  }
  add(dom) {
    if (!Array.isArray(dom.names) || !dom.names.length) {
      throw new Error("domains must have a non-empty array for 'names'");
    }
    if (dom.names.some(function (name) { return typeof name !== 'string'; })) {
      throw new Error("all domain names must be strings");
    }

    var modList = new ModuleList();
    if (Array.isArray(dom.modules)) {
      dom.modules.forEach(function (mod) {
        modList.add(mod);
      });
    }

    dom.id = require('crypto').randomBytes(4).toString('hex');
    dom.modules = modList;
    this.push(dom);
  }
}

class ConfigChanger {
  constructor(start) {
    Object.assign(this, JSON.parse(JSON.stringify(start)));
    delete this.device;

    this.http.modules = new ModuleList(this.http.modules);
    this.http.domains = new DomainList(this.http.domains);
    this.tls.modules  = new ModuleList(this.tls.modules);
    this.tls.domains  = new DomainList(this.tls.domains);
    this.tcp.modules  = new ModuleList(this.tcp.modules);
    this.dns.modules  = new ModuleList(this.dns.modules);
  }

  update(update) {
    var self = this;

    if (update.http && update.http.modules) {
      update.http.modules.forEach(self.http.modules.add.bind(self.http.modules));
      delete update.http.modules;
    }
    if (update.http && update.http.domains) {
      update.http.domains.forEach(self.http.domains.add.bind(self.http.domains));
      delete update.http.domains;
    }

    if (update.tls && update.tls.modules) {
      update.tls.modules.forEach(self.tls.modules.add.bind(self.tls.modules));
      delete update.tls.modules;
    }
    if (update.tls && update.tls.domains) {
      update.tls.domains.forEach(self.tls.domains.add.bind(self.tls.domains));
      delete update.tls.domains;
    }

    if (update.tcp && update.tcp.modules) {
      update.tcp.modules.forEach(self.tcp.modules.add.bind(self.tcp.modules));
      delete update.tcp.modules;
    }
    if (update.dns && update.dns.modules) {
      update.dns.modules.forEach(self.dns.modules.add.bind(self.dns.modules));
      delete update.dns.modules;
    }

    function mergeSettings(orig, changes) {
      Object.keys(changes).forEach(function (key) {
        // TODO: use an API that can properly handle updating arrays.
        if (!changes[key] || (typeof changes[key] !== 'object') || Array.isArray(changes[key])) {
          orig[key] = changes[key];
        }
        else if (!orig[key] || typeof orig[key] !== 'object') {
          orig[key] = changes[key];
        }
        else {
          mergeSettings(orig[key], changes[key]);
        }
      });
    }
    mergeSettings(this, update);

    return validate(this);
  }

  validate() {
    return validate(this);
  }
}
module.exports.ConfigChanger = ConfigChanger;