from enum import Enum
from pathlib import PurePosixPath

from app.utils.file_extensions import (
    DOCUMENT_EXTENSIONS,
    IMAGE_EXTENSIONS,
    get_document_extensions_for_service,
)

PLAINTEXT_EXTENSIONS = frozenset(
    {
        ".md",
        ".markdown",
        ".txt",
        ".text",
        ".json",
        ".jsonl",
        ".yaml",
        ".yml",
        ".toml",
        ".ini",
        ".cfg",
        ".conf",
        ".xml",
        ".css",
        ".scss",
        ".less",
        ".sass",
        ".py",
        ".pyw",
        ".pyi",
        ".pyx",
        ".js",
        ".jsx",
        ".ts",
        ".tsx",
        ".mjs",
        ".cjs",
        ".java",
        ".kt",
        ".kts",
        ".scala",
        ".groovy",
        ".c",
        ".h",
        ".cpp",
        ".cxx",
        ".cc",
        ".hpp",
        ".hxx",
        ".cs",
        ".fs",
        ".fsx",
        ".go",
        ".rs",
        ".rb",
        ".php",
        ".pl",
        ".pm",
        ".lua",
        ".swift",
        ".m",
        ".mm",
        ".r",
        ".jl",
        ".sh",
        ".bash",
        ".zsh",
        ".fish",
        ".bat",
        ".cmd",
        ".ps1",
        ".sql",
        ".graphql",
        ".gql",
        ".env",
        ".gitignore",
        ".dockerignore",
        ".editorconfig",
        ".makefile",
        ".cmake",
        ".log",
        ".rst",
        ".tex",
        ".bib",
        ".org",
        ".adoc",
        ".asciidoc",
        ".vue",
        ".svelte",
        ".astro",
        ".tf",
        ".hcl",
        ".proto",
    }
)

AUDIO_EXTENSIONS = frozenset(
    {".mp3", ".mp4", ".mpeg", ".mpga", ".m4a", ".wav", ".webm"}
)

DIRECT_CONVERT_EXTENSIONS = frozenset({".csv", ".tsv", ".html", ".htm", ".xhtml"})


class FileCategory(Enum):
    PLAINTEXT = "plaintext"
    AUDIO = "audio"
    DIRECT_CONVERT = "direct_convert"
    IMAGE = "image"
    UNSUPPORTED = "unsupported"
    DOCUMENT = "document"


def classify_file(filename: str) -> FileCategory:
    suffix = PurePosixPath(filename).suffix.lower()
    if suffix in PLAINTEXT_EXTENSIONS:
        return FileCategory.PLAINTEXT
    if suffix in AUDIO_EXTENSIONS:
        return FileCategory.AUDIO
    if suffix in DIRECT_CONVERT_EXTENSIONS:
        return FileCategory.DIRECT_CONVERT
    if suffix in IMAGE_EXTENSIONS:
        return FileCategory.IMAGE
    if suffix in DOCUMENT_EXTENSIONS:
        return FileCategory.DOCUMENT
    return FileCategory.UNSUPPORTED


def should_skip_for_service(filename: str, etl_service: str | None) -> bool:
    """Return True if *filename* cannot be processed by *etl_service*.

    Plaintext, audio, and direct-convert files are parser-agnostic and never
    skipped.  Image and document files are checked against the per-parser
    extension set (images fall back to the document parser when no vision LLM
    is available, so the same service constraint applies).
    """
    category = classify_file(filename)
    if category == FileCategory.UNSUPPORTED:
        return True
    if category in (FileCategory.DOCUMENT, FileCategory.IMAGE):
        suffix = PurePosixPath(filename).suffix.lower()
        return suffix not in get_document_extensions_for_service(etl_service)
    return False