Refactor Urls into url_builder.py

Refs #1026

datasette/url_builder.py

@@ -0,0 +1,60 @@
+from .utils import path_with_format, HASH_LENGTH
+import urllib
+
+
+class Urls:
+    def __init__(self, ds):
+        self.ds = ds
+
+    def path(self, path, format=None):
+        if path.startswith("/"):
+            path = path[1:]
+        path = self.ds.config("base_url") + path
+        if format is not None:
+            path = path_with_format(path=path, format=format)
+        return path
+
+    def instance(self, format=None):
+        return self.path("", format=format)
+
+    def static(self, path):
+        return self.path("-/static/{}".format(path))
+
+    def static_plugins(self, plugin, path):
+        return self.path("-/static-plugins/{}/{}".format(plugin, path))
+
+    def logout(self):
+        return self.path("-/logout")
+
+    def database(self, database, format=None):
+        db = self.ds.databases[database]
+        if self.ds.config("hash_urls") and db.hash:
+            path = self.path(
+                "{}-{}".format(database, db.hash[:HASH_LENGTH]), format=format
+            )
+        else:
+            path = self.path(database, format=format)
+        return path
+
+    def table(self, database, table, format=None):
+        path = "{}/{}".format(self.database(database), urllib.parse.quote_plus(table))
+        if format is not None:
+            path = path_with_format(path=path, format=format)
+        return path
+
+    def query(self, database, query, format=None):
+        path = "{}/{}".format(self.database(database), urllib.parse.quote_plus(query))
+        if format is not None:
+            path = path_with_format(path=path, format=format)
+        return path
+
+    def row(self, database, table, row_path, format=None):
+        path = "{}/{}".format(self.table(database, table), row_path)
+        if format is not None:
+            path = path_with_format(path=path, format=format)
+        return path
+
+    def row_blob(self, database, table, row_path, column):
+        return self.table(database, table) + "/{}.blob?_blob_column={}".format(
+            row_path, urllib.parse.quote_plus(column)
+        )