From fe4177addddaed799c20b4ae9337ce5c03ab70d4 Mon Sep 17 00:00:00 2001
From: Yurii Karabas <1998uriyyo@gmail.com>
Date: Thu, 13 May 2021 08:52:42 +0300
Subject: [PATCH] Revert "Merge pull request #87 from
 uriyyo/bugfix/default-page-number"

This reverts commit 819fef65fa9712513ebf067f206301911daffe84, reversing
changes made to 806f62563c09cacb4499fcc998e7c301523b1c9d.
---
 fastapi_pagination/default.py       |  4 ++--
 fastapi_pagination/links/default.py |  8 ++++----
 tests/base.py                       |  4 ++--
 tests/test_bases.py                 |  4 ++--
 tests/test_links.py                 | 18 +++++++++---------
 5 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/fastapi_pagination/default.py b/fastapi_pagination/default.py
index 1f5f2081..1d1c53a9 100644
--- a/fastapi_pagination/default.py
+++ b/fastapi_pagination/default.py
@@ -12,13 +12,13 @@
 
 
 class Params(BaseModel, AbstractParams):
-    page: int = Query(1, gt=0, description="Page number")
+    page: int = Query(0, ge=0, description="Page number")
     size: int = Query(50, gt=0, le=100, description="Page size")
 
     def to_raw_params(self) -> RawParams:
         return RawParams(
             limit=self.size,
-            offset=self.size * (self.page - 1),
+            offset=self.size * self.page,
         )
 
 
diff --git a/fastapi_pagination/links/default.py b/fastapi_pagination/links/default.py
index e70b1e79..2c8e3888 100644
--- a/fastapi_pagination/links/default.py
+++ b/fastapi_pagination/links/default.py
@@ -20,10 +20,10 @@ def __root_validator__(cls, value: Any) -> Any:
             page, size, total = [value[k] for k in ("page", "size", "total")]
 
             value["links"] = create_links(
-                first={"page": 1},
-                last={"page": ceil(total / size) + 1},
-                next={"page": page + 1} if page * size < total else None,
-                prev={"page": page - 1} if 1 <= page - 1 else None,
+                first={"page": 0},
+                last={"page": ceil(total / size)},
+                next={"page": page + 1} if (page + 1) * size < total else None,
+                prev={"page": page - 1} if 0 <= page - 1 else None,
             )
 
         return value
diff --git a/tests/base.py b/tests/base.py
index b5a3be69..e22fc266 100644
--- a/tests/base.py
+++ b/tests/base.py
@@ -20,9 +20,9 @@ class Config:
 
 
 _default_params = [
-    *[Params(page=i) for i in range(1, 10)],
+    *[Params(page=i) for i in range(10)],
     *[Params(size=i) for i in range(1, 100, 10)],
-    *[Params(page=i, size=j) for i in range(1, 10) for j in range(1, 50, 10)],
+    *[Params(page=i, size=j) for i in range(10) for j in range(1, 50, 10)],
 ]
 _limit_offset_params = [
     *[LimitOffsetParams(offset=i) for i in range(10)],
diff --git a/tests/test_bases.py b/tests/test_bases.py
index 4c7e2081..67bf5dbf 100644
--- a/tests/test_bases.py
+++ b/tests/test_bases.py
@@ -35,10 +35,10 @@ def test_custom_page_invalid_values():
 )
 def test_custom_page(cls):
     page_cls = cls.with_custom_options()
-    assert page_cls.__params_type__().dict() == {"size": 50, "page": 1}
+    assert page_cls.__params_type__().dict() == {"size": 50, "page": 0}
 
     page_cls = cls.with_custom_options(size=100)
-    assert page_cls.__params_type__().dict() == {"size": 100, "page": 1}
+    assert page_cls.__params_type__().dict() == {"size": 100, "page": 0}
 
     page_cls = cls.with_custom_options(size=100, page=100)
     assert page_cls.__params_type__().dict() == {"size": 100, "page": 100}
diff --git a/tests/test_links.py b/tests/test_links.py
index c41e12a0..c3b454cf 100644
--- a/tests/test_links.py
+++ b/tests/test_links.py
@@ -24,23 +24,23 @@ async def route():
         (
             "/default",
             None,
-            "/default?page=2",
             "/default?page=1",
-            "/default?page=5",
+            "/default?page=0",
+            "/default?page=4",
         ),
         (
-            "/default?page=2",
-            "/default?page=1",
-            "/default?page=3",
             "/default?page=1",
-            "/default?page=5",
+            "/default?page=0",
+            "/default?page=2",
+            "/default?page=0",
+            "/default?page=4",
         ),
         (
-            "/default?page=5",
             "/default?page=4",
+            "/default?page=3",
             None,
-            "/default?page=1",
-            "/default?page=5",
+            "/default?page=0",
+            "/default?page=4",
         ),
         (
             "/limit-offset",