add new pydantic-based plugin system

archivebox/plugantic/extractors.py

@@ -0,0 +1,118 @@
+__package__ = 'archivebox.plugantic'
+
+from typing import Optional, List, Literal, Annotated, Dict, Any
+from typing_extensions import Self
+
+from abc import ABC
+from pathlib import Path
+
+from pydantic import BaseModel, model_validator, field_serializer, AfterValidator
+
+from .binaries import (
+    Binary,
+    YtdlpBinary,
+    WgetBinary,
+)
+
+
+# stubs
+class Snapshot:
+    pass
+
+class ArchiveResult:
+    pass
+
+def get_wget_output_path(*args, **kwargs) -> Path:
+    return Path('.').resolve()
+
+
+
+def no_empty_args(args: List[str]) -> List[str]:
+    assert all(len(arg) for arg in args)
+    return args
+
+ExtractorName = Literal['wget', 'warc', 'media']
+
+HandlerFuncStr = Annotated[str, AfterValidator(lambda s: s.startswith('self.'))]
+CmdArgsList = Annotated[List[str], AfterValidator(no_empty_args)]
+
+
+class Extractor(ABC, BaseModel):
+    name: ExtractorName
+    binary: Binary
+
+    output_path_func: HandlerFuncStr = 'self.get_output_path'
+    should_extract_func: HandlerFuncStr = 'self.should_extract'
+    extract_func: HandlerFuncStr = 'self.extract'
+    exec_func: HandlerFuncStr = 'self.exec'
+
+    default_args: CmdArgsList = []
+    extra_args: CmdArgsList = []
+    args: Optional[CmdArgsList] = None
+
+    @model_validator(mode='after')
+    def validate_model(self) -> Self:
+        if self.args is None:
+            self.args = [*self.default_args, *self.extra_args]
+        return self
+
+    @field_serializer('binary', when_used='json')
+    def dump_binary(binary) -> str:
+        return binary.name
+
+    def get_output_path(self, snapshot) -> Path:
+        return Path(self.name)
+
+    def should_extract(self, snapshot) -> bool:
+        output_dir = self.get_output_path(snapshot)
+        if output_dir.glob('*.*'):
+            return False
+        return True
+
+
+    def extract(self, url: str, **kwargs) -> Dict[str, Any]:
+        output_dir = self.get_output_path(url, **kwargs)
+
+        cmd = [url, *self.args] if self.args is not None else [url, *self.default_args, *self.extra_args]
+        proc = self.exec(cmd, pwd=output_dir)
+
+        return {
+            'status': 'succeeded' if proc.returncode == 0 else 'failed',
+            'output': proc.stdout.decode().strip().split('\n')[-1],
+            'output_files': list(output_dir.glob('*.*')),
+
+            'stdout': proc.stdout.decode().strip(),
+            'stderr': proc.stderr.decode().strip(),
+            'returncode': proc.returncode,
+        }
+
+    def exec(self, args: CmdArgsList, pwd: Optional[Path]=None):
+        pwd = pwd or Path('.')
+        assert self.binary.loaded_provider
+        return self.binary.exec(args, pwd=pwd)
+
+
+class YtdlpExtractor(Extractor):
+    name: ExtractorName = 'media'
+    binary: Binary = YtdlpBinary()
+
+    def get_output_path(self, snapshot) -> Path:
+        return Path(self.name)
+
+
+class WgetExtractor(Extractor):
+    name: ExtractorName = 'wget'
+    binary: Binary = WgetBinary()
+
+    def get_output_path(self, snapshot) -> Path:
+        return get_wget_output_path(snapshot)
+
+
+class WarcExtractor(Extractor):
+    name: ExtractorName = 'warc'
+    binary: Binary = WgetBinary()
+
+    def get_output_path(self, snapshot) -> Path:
+        return get_wget_output_path(snapshot)
+
+