7 files changed, 174 insertions, 94 deletions

diff --git a/build b/build
index 1422fa8..63f7675 100755
--- a/build
+++ b/build
@@ -131,7 +131,7 @@ WASMCFLAGS="-std=c11 -fPIC -D_POSIX_C_SOURCE=199309L -pthread"
 WASMMFLAGS="-DTHREADS=$THREADS -DWASMSIMD"
 WASMLINKFLAGS="--no-entry -sEXPORT_NAME='Nissy' -sMODULARIZE \
         -sALLOW_MEMORY_GROWTH -sSTACK_SIZE=5MB -sPTHREAD_POOL_SIZE=$THREADS \
-        -sASYNCIFY -sLINKABLE -sEXPORT_ALL"
+        -sFETCH -sASYNCIFY -sLINKABLE -sEXPORT_ALL"
 
 if (command -v "python3-config" >/dev/null 2>&1) ; then
         PYTHON3_INCLUDES="$(python3-config --includes)"
diff --git a/web/adapter.cpp b/web/adapter.cpp
index 71a34ab..676390c 100644
--- a/web/adapter.cpp
+++ b/web/adapter.cpp
@@ -1,5 +1,12 @@
+extern "C" {
+        extern int addCallbackFunction(/* args intentionally unspecified */);
+        extern void callFunction(int, const char *);
+        extern int callFunctionInt(int);
+}
+
 #include "../cpp/nissy.h"
 #include "storage.h"
+#include "logging.h"
 
 #include <emscripten.h>
 #include <emscripten/bind.h>
@@ -10,78 +17,130 @@
 
 EM_ASYNC_JS(void, fake_async, (), {});
 
-extern "C" {
-        extern int addCallbackFunction(/* args intentionally unspecified */);
-        extern void callFunction(int, const char *);
-        extern int callFunctionInt(int);
+const std::set<std::string> available_solvers
+{
+        "h48h0k4",
+        "h48h1k2",
+        "h48h2k2",
+        "h48h3k2",
+        "h48h7k2",
+};
+
+std::map<std::string, nissy::solver> loaded_solvers;
+
+bool is_solver_available(const std::string& name)
+{
+        return available_solvers.contains(name);
 }
 
-static int logger_id = -1;
+bool is_solver_loaded(const std::string& name)
+{
+        return loaded_solvers.contains(name);
+}
 
-void log(std::string s)
+bool check_data(nissy::solver& solver)
 {
-        if (logger_id == -1)
-                return;
+        log("Checking data integrity "
+            "(this is done only once per session per solver)...\n");
 
-        callFunction(logger_id, s.c_str());
+        if (!solver.check_data().ok()) {
+                log("Error! Data is corrupted!\n");
+                return false;
+        }
+
+        return true;
 }
 
-void log_wrapper(const char *cstr, void *data)
+bool read_solver_data(nissy::solver& solver)
 {
-        log(cstr);
+        solver.data.resize(solver.size);
+
+        bool success = storage::read(solver.id, solver.size,
+            reinterpret_cast<char *>(solver.data.data()));
+
+        if (!success) {
+                log("Could not read data for solver " +
+                    solver.name + " from storage\n");
+                return false;
+        }
+
+        if (!check_data(solver)) {
+                log("Data for solver " + solver.name + " is corrupt!\n");
+                return false;
+        }
+
+        log("Data for solver " + solver.name + " read from storage\n");
+        loaded_solvers.insert({solver.name, solver});
+
+        return true;
 }
 
-void set_logger(int id)
+bool is_solver_valid(const std::string& name,
+    std::variant<nissy::solver, nissy::error>& se)
 {
-        logger_id = id;
-        nissy::set_logger(log_wrapper, NULL);
+        if (std::holds_alternative<nissy::error>(se)) {
+                log("Invalid solver " + name + "\n");
+                return false;
+        }
+
+        if (!is_solver_available(name)) {
+                log("Solver " + name + " is not available in this version\n");
+                return false;
+        }
+
+        return true;
 }
 
-// Some of the solvers are not available to the JS interface because of
-// memory limitations.
-const std::set<std::string> available_solvers
+bool init_solver_from_storage(const std::string& name)
 {
-        "h48h0k4",
-        "h48h1k2",
-        "h48h2k2",
-        "h48h3k2",
-        "h48h7k2",
-};
+        if (is_solver_loaded(name))
+                return true;
+        auto se = nissy::solver::get(name);
+        if (!is_solver_valid(name, se))
+                return false;
+        nissy::solver solver = std::get<nissy::solver>(se);
 
-std::map<std::string, nissy::solver> loaded_solvers;
+        return read_solver_data(solver);
+}
 
-// TODO: this should ask the user if they want to download or generate.
-bool init_solver(const std::string& name)
+bool init_solver_download(const std::string& name, const std::string& urlbase)
 {
+        if (is_solver_loaded(name))
+                return true;
         auto se = nissy::solver::get(name);
+        if (!is_solver_valid(name, se))
+                return false;
         nissy::solver solver = std::get<nissy::solver>(se);
 
-        solver.data.resize(solver.size);
-        if (storage::read(solver.id, solver.size,
-            reinterpret_cast<char *>(solver.data.data()))) {
-                log("Data for solver " + solver.name + " read from storage\n");
+        if (storage::download(solver.id, urlbase + "/" + solver.id)) {
+                return read_solver_data(solver);
         } else {
-                log("Could not read data for solver " + solver.name +
-                    " from storage, generating it\n");
-                auto err = solver.generate_data();
+                return false;
+        }
+}
 
-                if (!err.ok()) {
-                        log("Error generating the data!\n");
-                        return false;
-                }
+bool init_solver_generate(const std::string& name)
+{
+        if (is_solver_loaded(name))
+                return true;
+        auto se = nissy::solver::get(name);
+        if (!is_solver_valid(name, se))
+                return false;
+        nissy::solver solver = std::get<nissy::solver>(se);
+
+        if (!solver.generate_data().ok()) {
+                log("Error generating data for solver " + name + "!\n");
+                return false;
         }
 
-        log("Checking data integrity "
-            "(this is done only once per session per solver)...\n");
-        if (!solver.check_data().ok()) {
-                log("Error! Data is corrupted!\n");
+        if (!check_data(solver)) {
+                log("Data for solver " + name + " generated incorrectly!\n");
                 return false;
         }
-        loaded_solvers.insert({name, solver});
 
         if (storage::write(solver.id, solver.size,
             reinterpret_cast<const char *>(solver.data.data()))) {
-                log("Data for solver " + solver.name + " stored\n");
+                log("Data for solver " + name + " stored\n");
         } else {
                 log("Error storing the data (the solver is usable, "
                     "but the data will have to be re-generated next "
@@ -91,21 +150,6 @@ bool init_solver(const std::string& name)
         return true;
 }
 
-bool solver_valid(const std::string& name)
-{
-        if (loaded_solvers.contains(name) ||
-            (available_solvers.contains(name) && init_solver(name)))
-                return true;
-
-        auto se = nissy::solver::get(name);
-        if (std::holds_alternative<nissy::solver>(se))
-                log("The solver " + name + " is not available in "
-                   "the web version of Nissy. Use a native version.\n");
-        else
-                log("Invalid solver " + name + "\n");
-        return false;
-}
-
 int poll_status(void *arg)
 {
         if (arg == NULL || *(int *)arg == -1)
@@ -127,9 +171,11 @@ nissy::solver::solve_result solve(std::string name,
         // TODO figure out if there is a better way to do this.
         fake_async();
 
-        if (!solver_valid(name))
+        if (!is_solver_loaded(name)) {
+                log("Solver " + name + " is invalid or has not been loaded\n");
                 return nissy::solver::solve_result
                     {.err = nissy::error::INVALID_SOLVER};
+        }
 
         return loaded_solvers.at(name).solve(cube, nissflag, minmoves,
             maxmoves, maxsols, optimal, threads, NULL, &poll_status_id);
@@ -147,8 +193,10 @@ EMSCRIPTEN_BINDINGS(Nissy)
 
         emscripten::class_<nissy::error>("Error")
                 .function("ok", &nissy::error::ok)
-                .class_property("unsolvableWarning", &nissy::error::UNSOLVABLE_WARNING)
-                .class_property("unsolvableError", &nissy::error::UNSOLVABLE_ERROR)
+                .class_property("unsolvableWarning",
+                    &nissy::error::UNSOLVABLE_WARNING)
+                .class_property("unsolvableError",
+                    &nissy::error::UNSOLVABLE_ERROR)
                 .class_property("invalidCube", &nissy::error::INVALID_CUBE)
                 .class_property("invalidMoves", &nissy::error::INVALID_MOVES)
                 .class_property("invalidTrans", &nissy::error::INVALID_TRANS)
@@ -182,6 +230,13 @@ EMSCRIPTEN_BINDINGS(Nissy)
                 .property("solutions", &nissy::solver::solve_result::solutions)
                 ;
 
+        emscripten::function("isSolverAvailable", &is_solver_available);
+        emscripten::function("isSolverLoaded", &is_solver_loaded);
+        emscripten::function("initSolverFromStorage",
+            &init_solver_from_storage);
+        emscripten::function("initSolverDownload", &init_solver_download);
+        emscripten::function("initSolverGenerate", &init_solver_generate);
+
         emscripten::function("countMoves", &nissy::count_moves);
         emscripten::function("solve", &solve,
             emscripten::return_value_policy::take_ownership());
diff --git a/web/http/tables b/web/http/tables
new file mode 120000
index 0000000..b3afcac
--- /dev/null
+++ b/web/http/tables
@@ -0,0 +1 @@
+../../tables/
\ No newline at end of file
diff --git a/web/http/worker.mjs b/web/http/worker.mjs
index 831ef09..7ce1070 100644
--- a/web/http/worker.mjs
+++ b/web/http/worker.mjs
@@ -4,14 +4,24 @@ const nissy = await Nissy();
 nissy.setLogger(nissy._addCallbackFunction(console.log));
 
 onmessage = (e) => {
-  var cube = new nissy.Cube();
-  cube.move(e.data.scramble);
-  nissy.solve(e.data.solver, cube, nissy.NissFlag.normal, 0, 17, 1, 99, 4, -1)
-    .then((solve_result) => {
-      if (!solve_result.err.ok())
-        posMessage("Error while solving (solve returned " +
-          solve_result.err.value + ")");
-      else
-        postMessage(solve_result.solutions)
-    });
+//TODO: try to load from storage first, then download
+  nissy.initSolverDownload(e.data.solver, "/tables").then(
+  (download_result) => {
+    if (!download_result) {
+      postMessage("Error retrieving the solver data");
+    } else {
+      var cube = new nissy.Cube();
+      cube.move(e.data.scramble);
+
+      nissy.solve(e.data.solver, cube, nissy.NissFlag.normal,
+        0, 17, 1, 99, 4, -1).then(
+      (solve_result) => {
+        if (!solve_result.err.ok())
+          postMessage("Error while solving (solve returned " +
+            solve_result.err.value + ")");
+        else
+          postMessage(solve_result.solutions)
+      });
+    }
+  });
 };
diff --git a/web/logging.h b/web/logging.h
index b20a595..9ed4835 100644
--- a/web/logging.h
+++ b/web/logging.h
@@ -1,18 +1,3 @@
-#ifndef LOGGING_H
-#define LOGGING_H
-
-#include "../cpp/nissy.h"
-#include <emscripten/bind.h>
-#include <string>
-
-#define LOGGING_EMBIND \
-    emscripten::function("addCallbackFunction", &addCallbackFunction);
-
-extern "C" {
-        extern int addCallbackFunction();
-        extern void callFunction(int, const char *);
-}
-
 static int logger_id = -1;
 
 void log(std::string s)
@@ -33,5 +18,3 @@ void set_logger(int id)
         logger_id = id;
         nissy::set_logger(log_wrapper, NULL);
 }
-
-#endif
diff --git a/web/storage.cpp b/web/storage.cpp
index 4d0959f..cbf9e9c 100644
--- a/web/storage.cpp
+++ b/web/storage.cpp
@@ -13,13 +13,12 @@ std::string getprefix() {
 }
 
 EM_ASYNC_JS(int, loadfs, (), {
-        const dir = '/tables';
         const inBrowser = typeof window !== 'undefined';
         const inWorker = typeof WorkerGlobalScope !== 'undefined' &&
             self instanceof WorkerGlobalScope;
+        console.assert(inBrowser || inWorker, "Non-browsers not supported");
 
-        if (!(inBrowser || inWorker))
-                return;
+        const dir = '/tables';
 
         if (!FS.analyzePath(dir).exists)
                 FS.mkdir(dir);
@@ -38,6 +37,30 @@ EM_ASYNC_JS(int, loadfs, (), {
         }
 });
 
+EM_ASYNC_JS(int, download_and_store, (const char *key, const char *url), {
+        const inBrowser = typeof window !== 'undefined';
+        const inWorker = typeof WorkerGlobalScope !== 'undefined' &&
+            self instanceof WorkerGlobalScope;
+        console.assert(inBrowser || inWorker, "Non-browsers not supported");
+
+        url = UTF8ToString(url);
+        key = UTF8ToString(key);
+        let response = await fetch(url);
+        if (!response.ok) {
+                console.log("Error downloading data for " + key);
+                console.log("" + response.status + ": " + response.statusText);
+                return 0;
+        }
+
+        console.log("Data for " + key + " downloaded, writing to storage...");
+        let data = await response.bytes();
+        var stream = FS.open("/tables/" + key, "w+");
+        FS.write(stream, data, 0, data.length, 0);
+        FS.close(stream);
+        console.log("Data for " + key + " stored (" + data.length + " bytes)");
+        return 1;
+});
+
 bool storage::read(std::string key, size_t data_size, char *data)
 {
         loadfs();
@@ -65,3 +88,9 @@ bool storage::write(std::string key, size_t data_size, const char *data)
 
         return !ofs.fail();
 }
+
+int storage::download(std::string key, std::string url)
+{
+        loadfs();
+        return download_and_store(key.c_str(), url.c_str());
+}
diff --git a/web/storage.h b/web/storage.h
index fa6b748..b491742 100644
--- a/web/storage.h
+++ b/web/storage.h
@@ -1,7 +1,9 @@
 #include <string>
 #include <fstream>
+#include <emscripten/fetch.h>
 
 namespace storage {
-        bool read(std::string, size_t, char *);
-        bool write(std::string, size_t, const char *);
+        bool read(std::string key, size_t data_size, char *data);
+        bool write(std::string key, size_t data_size, const char *data);
+        int download(std::string key, std::string url);
 }