Start work on queries.

src/index.js

@@ -3,7 +3,7 @@ import ReactDOM from 'react-dom';
 import { Fetch } from './fetch.js';
 import { ProvideDB, DBQueryConsole, DBTypeEnum, DBSourceEnum } from './database.js';
 import { PhotoView, PhotoThumbView, PhotoTableLine } from './media.js';
-import { find_photos } from './queries.js';
+import { do_image_query, image_query_with_where } from './queries.js';
 
 import './index.css';
 
@@ -34,7 +34,7 @@ export class PhotoFromDB extends React.Component {
   }
 
   componentDidMount() {
-    find_photos("", this.props.database, "/test_photos", "/test_photos_thumbs").then(photos => {
+    do_image_query(image_query_with_where(""), this.props.database, "/test_photos", "/test_photos_thumbs").then(photos => {
       this.setState({ done: true, photo: photos[0] });
     });
   }

src/queries.js

@@ -1,15 +1,10 @@
 
 import { Photo, PhotoView, PhotoThumbView, create_photo } from './media.js';
 
-// This query will return database entries with the fields "id", "uniqueHash", "relativePath" (of the album) and "name" for each matching image.
-export function images_query(maybe_where) {
-    return "SELECT Images.id, Images.name, Images.uniqueHash, Albums.relativePath FROM Images INNER JOIN Albums ON Images.album=Albums.id " + (maybe_where ? maybe_where : "") + ";";
-}
-
-export function find_photos(maybe_where, database, collection_path, collection_thumbs_path) {
+export function do_image_query(query, database, collection_path, collection_thumbs_path) {
     return new Promise(function (resolve, reject) {
         var queries = [];
-        queries.push(images_query(maybe_where));
+        queries.push(query);
         database.queries_async(queries).then(res => {
             var photos = [];
             if (res && Array.isArray(res)) {
@@ -23,3 +18,72 @@ export function find_photos(maybe_where, database, collection_path, collection_t
         });
     });
 }
+
+export const MatchTypeEnum = {
+    MATCH_EQUALS: 1,
+    MATCH_LIKE: 2,
+};
+
+export const ImageFilterTypeEnum = {
+    MATCH_IMAGE_NAME: 1,
+}
+
+export const ResultTypeEnum = {
+    IMAGE: 1,
+}
+
+export class ImageFilter {
+    type = ImageFilterTypeEnum.MATCH_IMAGE_NAME;
+    match_against = "";
+    match_type = MatchTypeEnum.MATCH_EQUALS;
+}
+
+export class UserQuery {
+    image_filters = [];
+    include_result_types = [ ResultTypeEnum.IMAGE ];
+}
+
+export function image_filter_to_where(image_filter) {
+    var match_from = false;
+    var match_to = image_filter.match_against;
+    var match_operator = false;
+
+    if(image_filter.type == ImageFilterTypeEnum.MATCH_IMAGE_NAME) {
+        match_from = "Image.name";
+    } else {
+        throw new Error("Unsupported image filter type: " + image_filter.type);
+    }
+
+    if(image_filter.match_type == MatchTypeEnum.MATCH_EQUALS) {
+        match_operator = "=";
+    } else if(image_filter.match_type == MatchTypeEnum.MATCH_LIKE) {
+        match_operator = " LIKE ";
+    }
+
+    return match_from + match_operator + match_to;
+}
+
+// This query will return database entries with the fields "id", "uniqueHash", "relativePath" (of the album) and "name" for each matching image.
+export function image_query_with_where(maybe_where) {
+    return "SELECT Images.id, Images.name, Images.uniqueHash, Albums.relativePath FROM Images INNER JOIN Albums ON Images.album=Albums.id " + (maybe_where ? maybe_where : "") + ";";
+}
+
+export function maybe_image_query(user_query) {
+    if(!user_query.include_result_types.includes(ResultTypeEnum.IMAGE)) {
+        return false;
+    }
+    var where = false;
+    if(user_query.image_filters.length) {
+        where = "WHERE ";
+        var i = 0;
+        user_query.image_filters.forEach(elem => {
+            if(i > 0) {
+                where += "AND";
+            }
+            where += image_filter_to_where(elem) + " ";
+            i++;
+        });
+    }
+
+    return image_query_with_where(where);
+}