4 files changed, 150 insertions, 0 deletions
diff --git a/api/__init__.py b/api/__init__.py
new file mode 100644
index 0000000..685c125
--- /dev/null
+++ b/api/__init__.py
@@ -0,0 +1,3 @@
+from .v1.server import bp as v1_blueprint
+
+bp = v1_blueprint
diff --git a/api/v1/db.py b/api/v1/db.py
new file mode 100644
index 0000000..3d226c5
--- /dev/null
+++ b/api/v1/db.py
@@ -0,0 +1,35 @@
+from peewee import SqliteDatabase, ForeignKeyField, CharField, Model, IntegerField
+
+db = SqliteDatabase('datapackmanager.db')
+
+
+class BaseModel(Model):
+    class Meta:
+        database = db
+
+
+class User(BaseModel):
+    name = CharField()
+    id = IntegerField(primary_key=True)
+
+
+class Category(BaseModel):
+    name = CharField()
+    id = IntegerField(primary_key=True)
+
+
+class DataPack(BaseModel):
+    id = IntegerField(primary_key=True)
+    name = CharField()
+    description = CharField(max_length=10000)
+    category = ForeignKeyField(Category)
+    author = ForeignKeyField(User)
+
+
+class Version(BaseModel):
+    name = CharField()
+    datapack = ForeignKeyField(DataPack)
+
+
+db.create_tables([DataPack, Category, Version, User])
+__all__ = ('DataPack', 'Category', 'Version', 'db')
diff --git a/api/v1/server.py b/api/v1/server.py
new file mode 100644
index 0000000..96ff8da
--- /dev/null
+++ b/api/v1/server.py
@@ -0,0 +1,51 @@
+from flask import Blueprint, jsonify, abort, make_response, request
+
+from .db import Category, DataPack
+from .util import model_paginator, query_paginator, ConstrainFailed
+
+bp = Blueprint("api v1", __name__)
+
+
+@bp.errorhandler(ConstrainFailed)
+def handler(e: ConstrainFailed):
+    return make_response(jsonify({
+        'error': {
+            'description': e.description,
+            'parameter': e.parameter,
+            'reason': e.reason,
+        }
+    }), 404)
+
+
+@bp.route('/version/')
+def version():
+    return jsonify({
+        'version': '1.0.0',
+        'deprecated': False,
+    })
+
+
+@bp.route('/list/categories/')
+def list_categories():
+    return model_paginator(Category, lambda cat: {
+        'name': cat.name,
+        'id': cat.id,
+    })
+
+
+@bp.route('/list/datapacks')
+def list_datapacks():
+    category = request.args.get('category', '')
+    query = DataPack.select()
+    if category != '':
+        query = query.join(Category).where(DataPack.category.id == category)
+    return query_paginator(query, lambda dp: {
+        'name': dp.name,
+        'id': dp.id,
+        'category': dp.category.id,
+    })
+
+
+@bp.route('/<path:invalid_path>')
+def invalid_path(invalid_path):
+    abort(404)
diff --git a/api/v1/util.py b/api/v1/util.py
new file mode 100644
index 0000000..f2dddad
--- /dev/null
+++ b/api/v1/util.py
@@ -0,0 +1,61 @@
+import typing
+
+from flask import jsonify, request
+from peewee import Model, ModelSelect
+
+_V = typing.TypeVar('_V', bound=Model)
+
+
+def model_paginator(model: typing.Type[_V], mapping: typing.Callable[[_V], dict]):
+    return query_paginator(model.select(), mapping)
+
+
+class ConstrainFailed(Exception):
+    def __init__(self, description: str, parameter: str, reason: str):
+        self.reason = reason
+        self.parameter = parameter
+        self.description = description
+
+
+def try_or_fail_contrain(func: typing.Callable, parameter: str, value=None, default=None):
+    if value is None:
+        value = request.args.get(parameter, default)
+    try:
+        return func(value)
+    except BaseException as e:
+        func = func.__name__
+        raise ConstrainFailed(f"{func}({parameter}) failed with an exception", parameter,
+                              f"{func} raised {type(e).__name__}")
+
+
+def max_constrain(max: int, parameter: str, value=None, default=None):
+    value = try_or_fail_contrain(int, parameter, value, default)
+    if value > max:
+        raise ConstrainFailed(f"requested {parameter} too big", parameter, f'> {max}')
+    return value
+
+
+def min_constrain(min: int, parameter: str, value=None, default=None):
+    value = try_or_fail_contrain(int, parameter, value, default)
+    if value < min:
+        raise ConstrainFailed(f"requested {parameter} too big", parameter, f'< {min}')
+    return value
+
+
+def query_paginator(query: ModelSelect, mapping: typing.Callable[[_V], dict]):
+    size = try_or_fail_contrain(int, 'size', default='50')
+    max_constrain(50, 'size', size)
+    min_constrain(2, 'size', size)
+    offset = try_or_fail_contrain(int, 'offset', default='0')
+    min_constrain(0, 'offset', offset)
+    res = []
+    for obj in query.limit(size + 1).offset(offset):
+        res.append(mapping(obj))
+    more = len(res) > size
+    if more:
+        res[-1:] = []
+    return jsonify({
+        'more': more,
+        'next': offset + size if more else None,
+        'results': res,
+    })