1 files changed, 133 insertions, 0 deletions
diff --git a/script/core/signature.lua b/script/core/signature.lua
new file mode 100644
index 00000000..bbe35ffa
--- /dev/null
+++ b/script/core/signature.lua
@@ -0,0 +1,133 @@
+local getFunctionHover = require 'core.hover.function'
+local getFunctionHoverAsLib = require 'core.hover.lib_function'
+local getFunctionHoverAsEmmy = require 'core.hover.emmy_function'
+local findLib = require 'core.find_lib'
+local buildValueName = require 'core.hover.name'
+local findSource = require 'core.find_source'
+
+local function findCall(vm, pos)
+    local results = {}
+    vm:eachSource(function (src)
+        if      src.type == 'call'
+            and src.start <= pos
+            and src.finish >= pos
+        then
+            results[#results+1] = src
+        end
+    end)
+    if #results == 0 then
+        return nil
+    end
+    -- 可能处于 'func1(func2(' 的嵌套中，将最近的call放到最前面
+    table.sort(results, function (a, b)
+        return a.start > b.start
+    end)
+    return results
+end
+
+local function getSelect(args, pos)
+    if not args then
+        return 1
+    end
+    for i, arg in ipairs(args) do
+        if arg.start <= pos and arg.finish >= pos - 1 then
+            return i
+        end
+    end
+    return #args + 1
+end
+
+local function getFunctionSource(call)
+    local simple = call:get 'simple'
+    for i, source in ipairs(simple) do
+        if source == call then
+            return simple[i-1]
+        end
+    end
+    return nil
+end
+
+local function getHover(call, pos)
+    local args = call:bindCall()
+    if not args then
+        return nil
+    end
+
+    local value = call:findCallFunction()
+    if not value then
+        return nil
+    end
+
+    local select = getSelect(args, pos)
+    local source = getFunctionSource(call)
+    local object = source:get 'object'
+    local lib, fullkey = findLib(source)
+    local name = fullkey or buildValueName(source)
+    local hover
+    if lib then
+        hover = getFunctionHoverAsLib(name, lib, object, select)
+    else
+        local emmy = value:getEmmy()
+        if emmy and emmy.type == 'emmy.functionType' then
+            hover = getFunctionHoverAsEmmy(name, emmy, object, select)
+        else
+            ---@type emmyFunction
+            local func = value:getFunction()
+            hover = getFunctionHover(name, func, object, select)
+            local overLoads = func and func:getEmmyOverLoads()
+            if overLoads then
+                for _, ol in ipairs(overLoads) do
+                    hover = getFunctionHoverAsEmmy(name, ol, object, select)
+                end
+            end
+        end
+    end
+    return hover
+end
+
+local function isInFunctionOrTable(call, pos)
+    local args = call:bindCall()
+    if not args then
+        return false
+    end
+    local select = getSelect(args, pos)
+    local arg = args[select]
+    if not arg then
+        return false
+    end
+    if arg.type == 'function' or arg.type == 'table' then
+        return true
+    end
+    return false
+end
+
+return function (vm, pos)
+    local source = findSource(vm, pos) or findSource(vm, pos-1)
+    if not source or source.type == 'string' then
+        return
+    end
+    local calls = findCall(vm, pos)
+    if not calls or #calls == 0 then
+        return nil
+    end
+
+    local nearCall = calls[1]
+    if isInFunctionOrTable(nearCall, pos) then
+        return nil
+    end
+
+    local hover = getHover(nearCall, pos)
+    if not hover then
+        return nil
+    end
+
+    -- skip `name(`
+    local head = #hover.name + 1
+    hover.label = ('%s(%s)'):format(hover.name, hover.argStr)
+    if hover.argLabel then
+        hover.argLabel[1] = hover.argLabel[1] + head
+        hover.argLabel[2] = hover.argLabel[2] + head
+    end
+    
+    return { hover }
+end