From c0dc531ebefd8912819f3b6c8bda1fed3c7e750c Mon Sep 17 00:00:00 2001
From: Evgeny Zinoviev <me@ch1p.io>
Date: Wed, 31 Jan 2024 06:11:00 +0300
Subject: make it simple, but not simpler

---
 engine/router.php | 185 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 185 insertions(+)
 create mode 100644 engine/router.php

(limited to 'engine/router.php')

diff --git a/engine/router.php b/engine/router.php
new file mode 100644
index 0000000..401e177
--- /dev/null
+++ b/engine/router.php
@@ -0,0 +1,185 @@
+<?php
+
+const ROUTER_VERSION = 1;
+const ROUTER_MC_KEY = 'ch1p/routes';
+
+$RouterInput = [];
+$Routes = [
+    'children' => [],
+    're_children' => []
+];
+
+function router_init(): void {
+    global $Routes;
+    $mc = MC();
+
+    $from_cache = !is_dev();
+    $write_cache = !is_dev();
+
+    if ($from_cache) {
+        $cache = $mc->get(ROUTER_MC_KEY);
+
+        if ($cache === false || !isset($cache['version']) || $cache['version'] < ROUTER_VERSION) {
+            $from_cache = false;
+        } else {
+            $Routes = $cache['routes'];
+        }
+    }
+
+    if (!$from_cache) {
+        $routes_table = require_once APP_ROOT.'/routes.php';
+
+        foreach ($routes_table as $controller => $routes) {
+            foreach ($routes as $route => $resolve)
+                router_add($route, $controller.' '.$resolve);
+        }
+
+        if ($write_cache)
+            $mc->set(ROUTER_MC_KEY, ['version' => ROUTER_VERSION, 'routes' => $Routes]);
+    }
+}
+
+function router_add(string $template, string $value): void {
+    global $Routes;
+    if ($template == '')
+        return;
+
+    // expand {enum,erat,ions}
+    $templates = [[$template, $value]];
+    if (preg_match_all('/\{([\w\d_\-,]+)\}/', $template, $matches)) {
+        foreach ($matches[1] as $match_index => $variants) {
+            $variants = explode(',', $variants);
+            $variants = array_map('trim', $variants);
+            $variants = array_filter($variants, function($s) { return $s != ''; });
+
+            for ($i = 0; $i < count($templates); ) {
+                list($template, $value) = $templates[$i];
+                $new_templates = [];
+                foreach ($variants as $variant_index => $variant) {
+                    $new_templates[] = [
+                        str_replace_once($matches[0][$match_index], $variant, $template),
+                        str_replace('${'.($match_index+1).'}', $variant, $value)
+                    ];
+                }
+                array_splice($templates, $i, 1, $new_templates);
+                $i += count($new_templates);
+            }
+        }
+    }
+
+    // process all generated routes
+    foreach ($templates as $template) {
+        list($template, $value) = $template;
+
+        $start_pos = 0;
+        $parent = &$Routes;
+        $template_len = strlen($template);
+
+        while ($start_pos < $template_len) {
+            $slash_pos = strpos($template, '/', $start_pos);
+            if ($slash_pos !== false) {
+                $part = substr($template, $start_pos, $slash_pos-$start_pos+1);
+                $start_pos = $slash_pos+1;
+            } else {
+                $part = substr($template, $start_pos);
+                $start_pos = $template_len;
+            }
+
+            $parent = &_router_add($parent, $part,
+                $start_pos < $template_len ? null : $value);
+        }
+    }
+}
+
+function &_router_add(&$parent, $part, $value = null) {
+    $par_pos = strpos($part, '(');
+    $is_regex = $par_pos !== false && ($par_pos == 0 || $part[$par_pos-1] != '\\');
+
+    $children_key = !$is_regex ? 'children' : 're_children';
+
+    if (isset($parent[$children_key][$part])) {
+        if (is_null($value)) {
+            $parent = &$parent[$children_key][$part];
+        } else {
+            if (!isset($parent[$children_key][$part]['value'])) {
+                $parent[$children_key][$part]['value'] = $value;
+            } else {
+                trigger_error(__METHOD__.': route is already defined');
+            }
+        }
+        return $parent;
+    }
+
+    $child = [
+        'children' => [],
+        're_children' => []
+    ];
+    if (!is_null($value))
+        $child['value'] = $value;
+
+    $parent[$children_key][$part] = $child;
+    return $parent[$children_key][$part];
+}
+
+function router_find($uri) {
+    global $Routes;
+    if ($uri != '/' && $uri[0] == '/')
+        $uri = substr($uri, 1);
+
+    $start_pos = 0;
+    $parent = &$Routes;
+    $uri_len = strlen($uri);
+    $matches = [];
+
+    while ($start_pos < $uri_len) {
+        $slash_pos = strpos($uri, '/', $start_pos);
+        if ($slash_pos !== false) {
+            $part = substr($uri, $start_pos, $slash_pos-$start_pos+1);
+            $start_pos = $slash_pos+1;
+        } else {
+            $part = substr($uri, $start_pos);
+            $start_pos = $uri_len;
+        }
+
+        $found = false;
+        if (isset($parent['children'][$part])) {
+            $parent = &$parent['children'][$part];
+            $found = true;
+        } else if (!empty($parent['re_children'])) {
+            foreach ($parent['re_children'] as $re => &$child) {
+                $exp = '#^'.$re.'$#';
+                $re_result = preg_match($exp, $part, $match);
+                if ($re_result === false) {
+                    logError(__METHOD__.": regex $exp failed");
+                    continue;
+                }
+
+                if ($re_result) {
+                    if (count($match) > 1)
+                        $matches = array_merge($matches, array_slice($match, 1));
+                    $parent = &$child;
+                    $found = true;
+                    break;
+                }
+            }
+        }
+
+        if (!$found)
+            return null;
+    }
+
+    if (!isset($parent['value']))
+        return null;
+
+    $value = $parent['value'];
+    if (!empty($matches)) {
+        foreach ($matches as $i => $match) {
+            $needle = '$('.($i+1).')';
+            $pos = strpos($value, $needle);
+            if ($pos !== false)
+                $value = substr_replace($value, $match, $pos, strlen($needle));
+        }
+    }
+
+    return $value;
+}
-- 
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