[move-ide] Refactored auto-completions implementation to multiple fil…

…es (#19236)

## Description 

The auto-completions implementation was becoming unwieldy and this PR
splits it up to multiple files in a separate directory. This a pure
refactoring - other than some name changes, added comments, and moving
code around, no modifications have been made

## Test plan 

All existing tests must pass

external-crates/move/crates/move-analyzer/src/analyzer.rs

@@ -19,7 +19,7 @@ use std::{
 };
 
 use crate::{
-    completion::on_completion_request, context::Context, inlay_hints, symbols,
+    completions::on_completion_request, context::Context, inlay_hints, symbols,
     vfs::on_text_document_sync_notification,
 };
 use url::Url;

external-crates/move/crates/move-analyzer/src/completions/dot.rs

@@ -0,0 +1,115 @@
+// Copyright (c) The Move Contributors
+// SPDX-License-Identifier: Apache-2.0
+
+// Auto-completion for the dot operator, e.g., `struct.` or `value.foo()`.`
+
+use crate::{
+    completions::utils::{call_completion_item, mod_defs},
+    symbols::{type_to_ide_string, DefInfo, FunType, Symbols},
+    utils::lsp_position_to_loc,
+};
+use lsp_types::{
+    CompletionItem, CompletionItemKind, CompletionItemLabelDetails, InsertTextFormat, Position,
+};
+use move_compiler::{
+    expansion::ast::ModuleIdent_,
+    shared::{ide::AutocompleteMethod, Identifier},
+};
+use move_symbol_pool::Symbol;
+
+use std::path::Path;
+
+/// Handle "dot" auto-completion at a given position.
+pub fn dot_completions(
+    symbols: &Symbols,
+    use_fpath: &Path,
+    position: &Position,
+) -> (Vec<CompletionItem>, bool) {
+    let mut completions = vec![];
+    let mut completion_finalized = false;
+    let Some(fhash) = symbols.file_hash(use_fpath) else {
+        eprintln!("no dot completions due to missing file");
+        return (completions, completion_finalized);
+    };
+    let Some(loc) = lsp_position_to_loc(&symbols.files, fhash, position) else {
+        eprintln!("no dot completions due to missing loc");
+        return (completions, completion_finalized);
+    };
+    let Some(info) = symbols.compiler_info.get_autocomplete_info(fhash, &loc) else {
+        return (completions, completion_finalized);
+    };
+    // we found auto-completion info, so don't look for any more completions
+    // even if if it does not contain any
+    completion_finalized = true;
+    for AutocompleteMethod {
+        method_name,
+        target_function: (mod_ident, function_name),
+    } in &info.methods
+    {
+        let call_completion = if let Some(DefInfo::Function(
+            ..,
+            fun_type,
+            _,
+            type_args,
+            arg_names,
+            arg_types,
+            ret_type,
+            _,
+        )) = fun_def_info(symbols, mod_ident.value, function_name.value())
+        {
+            call_completion_item(
+                &mod_ident.value,
+                matches!(fun_type, FunType::Macro),
+                Some(method_name),
+                &function_name.value(),
+                type_args,
+                arg_names,
+                arg_types,
+                ret_type,
+                /* inside_use */ false,
+            )
+        } else {
+            // this shouldn't really happen as we should be able to get
+            // `DefInfo` for a function but if for some reason we cannot,
+            // let's generate simpler autotompletion value
+            eprintln!("incomplete dot item");
+            CompletionItem {
+                label: format!("{method_name}()"),
+                kind: Some(CompletionItemKind::METHOD),
+                insert_text: Some(method_name.to_string()),
+                insert_text_format: Some(InsertTextFormat::PLAIN_TEXT),
+                ..Default::default()
+            }
+        };
+        completions.push(call_completion);
+    }
+    for (n, t) in &info.fields {
+        let label_details = Some(CompletionItemLabelDetails {
+            detail: None,
+            description: Some(type_to_ide_string(t, /* verbose */ false)),
+        });
+        let init_completion = CompletionItem {
+            label: n.to_string(),
+            label_details,
+            kind: Some(CompletionItemKind::FIELD),
+            insert_text: Some(n.to_string()),
+            insert_text_format: Some(InsertTextFormat::PLAIN_TEXT),
+            ..Default::default()
+        };
+        completions.push(init_completion);
+    }
+
+    (completions, completion_finalized)
+}
+
+/// Get the `DefInfo` for a function definition.
+fn fun_def_info(symbols: &Symbols, mod_ident: ModuleIdent_, name: Symbol) -> Option<&DefInfo> {
+    let Some(mod_defs) = mod_defs(symbols, &mod_ident) else {
+        return None;
+    };
+
+    let Some(fdef) = mod_defs.functions.get(&name) else {
+        return None;
+    };
+    symbols.def_info(&fdef.name_loc)
+}