1 files changed, 122 insertions, 0 deletions
diff --git a/src/Build/RelationshipHandler.php b/src/Build/RelationshipHandler.php
new file mode 100644
index 0000000..33f8618
--- /dev/null
+++ b/src/Build/RelationshipHandler.php
@@ -0,0 +1,122 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Zhineng\Region\Build;
+
+use Symfony\Component\VarExporter\VarExporter;
+
+final class RelationshipHandler implements RegionHandler
+{
+    /**
+     * @var array<string, int[]>
+     */
+    private array $data = [];
+
+    public function handle(string $code, string $name): void
+    {
+        if ($this->belongsToGroup($code)) {
+            $this->data[$this->groupKey($code)] = [];
+        }
+
+        if ($this->isProvince($code)) {
+            return;
+        }
+
+        $group = $this->resolveGroupFor($code);
+
+        $this->data[$group][] = (int) $code;
+    }
+
+    private function belongsToGroup(string $code): bool
+    {
+        return $this->isProvince($code)
+            || $this->isCity($code);
+    }
+
+    private function isProvince(string $code): bool
+    {
+        return substr($code, -4) === '0000';
+    }
+
+    private function groupKey(string $code): string
+    {
+        return '_'.$code;
+    }
+
+    private function isCity(string $code): bool
+    {
+        return substr($code, -2) === '00';
+    }
+
+    private function isDistrict(string $code): bool
+    {
+        return substr($code, -2) !== '00';
+    }
+
+    private function resolveGroupFor(string $code): string
+    {
+        if ($this->isDistrict($code)) {
+            return $this->resolveGroupForDistrict($code);
+        }
+
+        return $this->resolveGroupForCity($code);
+    }
+
+    private function resolveGroupForDistrict(string $code): string
+    {
+        if ($this->hasCityGroup($code)) {
+            return $this->groupKey($this->cityKey($code));
+        }
+
+        if ($this->hasProvinceGroup($code)) {
+            return $this->groupKey($this->provinceKey($code));
+        }
+
+        throw new \InvalidArgumentException(sprintf(
+            'Could not resolve the group for key [%s].', $code
+        ));
+    }
+
+    private function resolveGroupForCity(string $code): string
+    {
+        if ($this->hasProvinceGroup($code)) {
+            return $this->groupKey($this->provinceKey($code));
+        }
+
+        throw new \InvalidArgumentException(sprintf(
+            'Could not resolve the group for key [%s].', $code
+        ));
+    }
+
+    private function hasCityGroup(string $code): bool
+    {
+        $key = $this->groupKey($this->cityKey($code));
+
+        return isset($this->data[$key]);
+    }
+
+    private function cityKey(string $code): string
+    {
+        return substr($code, 0, 4).'00';
+    }
+
+    private function hasProvinceGroup(string $code): bool
+    {
+        $key = $this->groupKey($this->provinceKey($code));
+
+        return isset($this->data[$key]);
+    }
+
+    private function provinceKey(string $code): string
+    {
+        return substr($code, 0, 2).'0000';
+    }
+
+    public function export(string $destination): void
+    {
+        $exported = VarExporter::export($this->data);
+
+        file_put_contents($destination, '<?php return '.$exported.';');
+    }
+}