5 files changed, 139 insertions, 5 deletions
diff --git a/src/shared/settings/default.js b/src/shared/settings/default.js
index d187565..6425354 100644
--- a/src/shared/settings/default.js
+++ b/src/shared/settings/default.js
@@ -58,6 +58,8 @@ export default {
       "duckduckgo": "https://duckduckgo.com/?q={}",
       "twitter": "https://twitter.com/search?q={}",
       "wikipedia": "https://en.wikipedia.org/w/index.php?search={}"
+    },
+    "properties": {
     }
   }
 }`,
diff --git a/src/shared/settings/properties.js b/src/shared/settings/properties.js
new file mode 100644
index 0000000..ff8039b
--- /dev/null
+++ b/src/shared/settings/properties.js
@@ -0,0 +1,15 @@
+const types = {
+  // TODO describe property types here
+  // mystr: 'string',
+  // mynum: 'number',
+  // mybool: 'boolean',
+};
+
+const defaults = {
+  // TODO describe property defaults values
+  // mystr: 'hello',
+  // mynum: 123,
+  // mybool: true,
+};
+
+export { types, defaults };
diff --git a/src/shared/settings/storage.js b/src/shared/settings/storage.js
new file mode 100644
index 0000000..1edb441
--- /dev/null
+++ b/src/shared/settings/storage.js
@@ -0,0 +1,31 @@
+import DefaultSettings from './default';
+import * as settingsValues from './values';
+
+const loadRaw = () => {
+  return browser.storage.local.get('settings').then(({ settings }) => {
+    if (!settings) {
+      return DefaultSettings;
+    }
+    return Object.assign({}, DefaultSettings, settings);
+  });
+};
+
+const loadValue = () => {
+  return loadRaw().then((settings) => {
+    let value = JSON.parse(DefaultSettings.json);
+    if (settings.source === 'json') {
+      value = settingsValues.valueFromJson(settings.json);
+    } else if (settings.source === 'form') {
+      value = settingsValues.valueFromForm(settings.form);
+    }
+    return value;
+  });
+};
+
+const save = (settings) => {
+  return browser.storage.local.set({
+    settings,
+  });
+};
+
+export { loadRaw, loadValue, save };
diff --git a/src/shared/settings/validator.js b/src/shared/settings/validator.js
new file mode 100644
index 0000000..1589420
--- /dev/null
+++ b/src/shared/settings/validator.js
@@ -0,0 +1,76 @@
+import operations from 'shared/operations';
+import * as properties from './properties';
+
+const VALID_TOP_KEYS = ['keymaps', 'search', 'blacklist', 'properties'];
+const VALID_OPERATION_VALUES = Object.keys(operations).map((key) => {
+  return operations[key];
+});
+
+const validateInvalidTopKeys = (settings) => {
+  let invalidKey = Object.keys(settings).find((key) => {
+    return !VALID_TOP_KEYS.includes(key);
+  });
+  if (invalidKey) {
+    throw Error(`Unknown key: "${invalidKey}"`);
+  }
+};
+
+const validateKeymaps = (keymaps) => {
+  for (let key of Object.keys(keymaps)) {
+    let value = keymaps[key];
+    if (!VALID_OPERATION_VALUES.includes(value.type)) {
+      throw Error(`Unknown operation: "${value.type}"`);
+    }
+  }
+};
+
+const validateSearch = (search) => {
+  let engines = search.engines;
+  for (let key of Object.keys(engines)) {
+    if (/\s/.test(key)) {
+      throw new Error(
+        `While space in search engine name is not allowed: "${key}"`
+      );
+    }
+    let url = engines[key];
+    if (!url.match(/{}/)) {
+      throw new Error(`No {}-placeholders in URL of "${key}"`);
+    }
+    if (url.match(/{}/g).length > 1) {
+      throw new Error(`Multiple {}-placeholders in URL of "${key}"`);
+    }
+  }
+
+  if (!search.default) {
+    throw new Error(`Default engine is not set`);
+  }
+  if (!Object.keys(engines).includes(search.default)) {
+    throw new Error(`Default engine "${search.default}" not found`);
+  }
+};
+
+const validateProperties = (props) => {
+  for (let name of Object.keys(props)) {
+    if (!properties.types[name]) {
+      throw new Error(`Unknown property name: "${name}"`);
+    }
+    if (typeof props[name] !== properties.types[name]) {
+      throw new Error(`Invalid type for property: "${name}"`);
+    }
+  }
+};
+
+const validate = (settings) => {
+  validateInvalidTopKeys(settings);
+  if (settings.keymaps) {
+    validateKeymaps(settings.keymaps);
+  }
+  if (settings.search) {
+    validateSearch(settings.search);
+  }
+  if (settings.properties) {
+    validateProperties(settings.properties);
+  }
+};
+
+export { validate };
diff --git a/src/shared/settings/values.js b/src/shared/settings/values.js
index 4e55fa0..bd03be2 100644
--- a/src/shared/settings/values.js
+++ b/src/shared/settings/values.js
@@ -1,3 +1,5 @@
+import * as properties from './properties';
+
 const operationFromFormName = (name) => {
   let [type, argStr] = name.split('?');
   let args = {};
@@ -44,9 +46,12 @@ const valueFromForm = (form) => {
     }
   }
 
-  let blacklist = form.blacklist;
-
-  return { keymaps, search, blacklist };
+  return {
+    keymaps,
+    search,
+    blacklist: form.blacklist,
+    properties: form.properties
+  };
 };
 
 const jsonFromValue = (value) => {
@@ -78,9 +83,14 @@ const formFromValue = (value, allowedOps) => {
     }
   }
 
-  let blacklist = value.blacklist;
+  let formProperties = Object.assign({}, properties.defaults, value.properties);
 
-  return { keymaps, search, blacklist };
+  return {
+    keymaps,
+    search,
+    blacklist: value.blacklist,
+    properties: formProperties,
+  };
 };
 
 const jsonFromForm = (form) => {