From 713a624b0038f8bc67457d44bdfd6564a1f9b077 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jelmer=20Vernoo=C4=B3?= <jelmer@jelmer.uk>
Date: Mon, 8 Feb 2021 20:48:23 +0000
Subject: [PATCH] More work on resolvers.

---
 ognibuild/__main__.py | 44 ++++++++++++++++++++++++++++++++++++++++---
 ognibuild/resolver.py | 39 ++++++++++++++++++++++++++++++++++++--
 2 files changed, 78 insertions(+), 5 deletions(-)

diff --git a/ognibuild/__main__.py b/ognibuild/__main__.py
index b0a330b..7dff0e3 100644
--- a/ognibuild/__main__.py
+++ b/ognibuild/__main__.py
@@ -18,14 +18,30 @@
 import logging
 import os
 import sys
+from . import UpstreamPackage
 from .buildsystem import NoBuildToolsFound
 from .build import run_build
 from .clean import run_clean
 from .dist import run_dist
 from .install import run_install
+from .resolver import (
+    AptResolver,
+    ExplainResolver,
+    AutoResolver,
+    NativeResolver,
+    MissingDependencies,
+    )
 from .test import run_test
 
 
+def install_declared_requirements(resolver, requirements, subcommand):
+    missing = []
+    for req in requirements:
+        # TODO(jelmer): Look at stage
+        missing.append(UpstreamPackage(req.package.family, req.package.name))
+    resolver.install(missing)
+
+
 def main():
     import argparse
 
@@ -41,6 +57,10 @@ def main():
         '--resolve', choices=['explain', 'apt', 'native'],
         default='apt',
         help='What to do about missing dependencies')
+    parser.add_argument(
+        '--ignore-declared-dependencies',
+        action='store_true',
+        help='Ignore declared dependencies, follow build errors only')
     args = parser.parse_args()
     if args.schroot:
         from .session.schroot import SchrootSession
@@ -52,16 +72,25 @@ def main():
         session = PlainSession()
     with session:
         if args.resolve == 'apt':
-            from .resolver import AptResolver
             resolver = AptResolver.from_session(session)
         elif args.resolve == 'explain':
-            from .resolver import ExplainResolver
             resolver = ExplainResolver.from_session(session)
         elif args.resolve == 'native':
-            from .resolver import NativeResolver
             resolver = NativeResolver.from_session(session)
+        elif args.resolver == 'auto':
+            resolver = AutoResolver.from_session(session)
         os.chdir(args.directory)
         try:
+            if not args.ignore_declared_dependencies:
+                from upstream_ontologist.guess import get_upstream_info
+                buildsystem, requirements, metadata = get_upstream_info(
+                    path=args.directory,
+                    trust_package=True,
+                    net_access=True,
+                    consult_external_directory=True,
+                    check=True)
+                install_declared_requirements(
+                    resolver, requirements, args.subcommand)
             if args.subcommand == 'dist':
                 run_dist(session=session, resolver=resolver)
             if args.subcommand == 'build':
@@ -75,6 +104,15 @@ def main():
         except NoBuildToolsFound:
             logging.info("No build tools found.")
             return 1
+        except MissingDependencies as e:
+            for req in e.requirements:
+                note('Missing dependency (%s:%s)' % (
+                     req.family, req.name))
+                for resolver in [
+                        AptResolver.from_session(session),
+                        NativeResolver.from_session(session)]:
+                    note('  %s' % (resolver.explain([req]), ))
+            return 2
         return 0
 
 
diff --git a/ognibuild/resolver.py b/ognibuild/resolver.py
index 288e9d7..dffb263 100644
--- a/ognibuild/resolver.py
+++ b/ognibuild/resolver.py
@@ -16,6 +16,12 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 
 
+class MissingDependencies(Exception):
+
+    def __init__(self, reqs):
+        self.requirements = reqs
+
+
 class Resolver(object):
 
     def install(self, requirements):
@@ -36,17 +42,31 @@ class AptResolver(Resolver):
         return cls(AptManager(session))
 
     def install(self, requirements):
-        self.apt.install(list(self.resolve(requirements)))
+        missing = []
+        for req in requirements:
+            pps = list(self._possible_paths(req))
+            if (not pps or
+                    not any(self.apt.session.exists(p) for p in pps)):
+                missing.append(req)
+        if missing:
+            self.apt.install(list(self.resolve(missing)))
 
     def explain(self, requirements):
         raise NotImplementedError(self.explain)
 
+    def _possible_paths(self, req):
+        if req.family == 'binary':
+            yield '/usr/bin/%s' % req.name
+        else:
+            return
+
     def resolve(self, requirements):
         for req in requirements:
             if req.family == 'python3':
                 yield 'python3-%s' % req.name
             else:
-                yield self.apt.find_file('/usr/bin/%s' % req.name)
+                path = list(self._possible_paths(req))
+                raise NotImplementedError
 
 
 class NativeResolver(Resolver):
@@ -67,6 +87,21 @@ class NativeResolver(Resolver):
 
 class ExplainResolver(Resolver):
 
+    def __init__(self, session):
+        self.session = session
+
+    @classmethod
+    def from_session(cls, session):
+        return cls(session)
+
+    def install(self, requirements):
+        raise MissingDependencies(requirements)
+
+
+class AutoResolver(Resolver):
+    """Automatically find out the most appropriate way to instal dependencies.
+    """
+
     def __init__(self, session):
         self.session = session