# Copyright 2017-2020 Palantir Technologies, Inc.
# Copyright 2021- Python Language Server Contributors.

import logging
from rope.contrib.codeassist import code_assist, sorted_proposals

from pylsp import hookimpl, lsp


log = logging.getLogger(__name__)


@hookimpl
def pylsp_settings():
    # Default rope_completion to disabled
    return {'plugins': {'rope_completion': {'enabled': False, 'eager': False}}}


def _resolve_completion(completion, data):
    try:
        doc = data.get_doc()
    except AttributeError:
        doc = ""
    completion['detail'] = '{0} {1}'.format(data.scope or "", data.name)
    completion['documentation'] = doc
    return completion


@hookimpl
def pylsp_completions(config, workspace, document, position):
    # pylint: disable=too-many-locals

    settings = config.plugin_settings('rope_completion', document_path=document.path)
    resolve_eagerly = settings.get('eager', False)

    # Rope is a bit rubbish at completing module imports, so we'll return None
    word = document.word_at_position({
        # The -1 should really be trying to look at the previous word, but that might be quite expensive
        # So we only skip import completions when the cursor is one space after `import`
        'line': position['line'], 'character': max(position['character'] - 1, 0),
    })
    if word == 'import':
        return None

    offset = document.offset_at_position(position)
    rope_config = config.settings(document_path=document.path).get('rope', {})
    rope_project = workspace._rope_project_builder(rope_config)
    document_rope = document._rope_resource(rope_config)

    try:
        definitions = code_assist(rope_project, document.source, offset, document_rope, maxfixes=3)
    except Exception as e:  # pylint: disable=broad-except
        log.debug("Failed to run Rope code assist: %s", e)
        return []

    definitions = sorted_proposals(definitions)
    new_definitions = []
    for d in definitions:
        item = {
            'label': d.name,
            'kind': _kind(d),
            'sortText': _sort_text(d),
            'data': {
                'doc_uri': document.uri
            }
        }
        if resolve_eagerly:
            item = _resolve_completion(item, d)
        new_definitions.append(item)

    # most recently retrieved completion items, used for resolution
    document.shared_data['LAST_ROPE_COMPLETIONS'] = {
        # label is the only required property; here it is assumed to be unique
        completion['label']: (completion, data)
        for completion, data in zip(new_definitions, definitions)
    }

    definitions = new_definitions

    return definitions or None


@hookimpl
def pylsp_completion_item_resolve(completion_item, document):
    """Resolve formatted completion for given non-resolved completion"""
    completion, data = document.shared_data['LAST_ROPE_COMPLETIONS'].get(completion_item['label'])
    return _resolve_completion(completion, data)


def _sort_text(definition):
    """ Ensure builtins appear at the bottom.
    Description is of format <type>: <module>.<item>
    """
    if definition.name.startswith("_"):
        # It's a 'hidden' func, put it next last
        return 'z' + definition.name
    if definition.scope == 'builtin':
        return 'y' + definition.name

    # Else put it at the front
    return 'a' + definition.name


def _kind(d):
    """ Return the LSP type """
    MAP = {
        'none': lsp.CompletionItemKind.Value,
        'type': lsp.CompletionItemKind.Class,
        'tuple': lsp.CompletionItemKind.Class,
        'dict': lsp.CompletionItemKind.Class,
        'dictionary': lsp.CompletionItemKind.Class,
        'function': lsp.CompletionItemKind.Function,
        'lambda': lsp.CompletionItemKind.Function,
        'generator': lsp.CompletionItemKind.Function,
        'class': lsp.CompletionItemKind.Class,
        'instance': lsp.CompletionItemKind.Reference,
        'method': lsp.CompletionItemKind.Method,
        'builtin': lsp.CompletionItemKind.Class,
        'builtinfunction': lsp.CompletionItemKind.Function,
        'module': lsp.CompletionItemKind.Module,
        'file': lsp.CompletionItemKind.File,
        'xrange': lsp.CompletionItemKind.Class,
        'slice': lsp.CompletionItemKind.Class,
        'traceback': lsp.CompletionItemKind.Class,
        'frame': lsp.CompletionItemKind.Class,
        'buffer': lsp.CompletionItemKind.Class,
        'dictproxy': lsp.CompletionItemKind.Class,
        'funcdef': lsp.CompletionItemKind.Function,
        'property': lsp.CompletionItemKind.Property,
        'import': lsp.CompletionItemKind.Module,
        'keyword': lsp.CompletionItemKind.Keyword,
        'constant': lsp.CompletionItemKind.Variable,
        'variable': lsp.CompletionItemKind.Variable,
        'value': lsp.CompletionItemKind.Value,
        'param': lsp.CompletionItemKind.Variable,
        'statement': lsp.CompletionItemKind.Keyword,
    }

    return MAP.get(d.type)