refactor(send.lua): enhance pipeline handling to rely only on treesitter

lua/r/send.lua

@@ -645,22 +645,94 @@ M.line = function(m)
     end
 end
 
--- Function to check if a string ends with a specific suffix
----@param str string
----@param suffix string
----@return boolean
-local function ends_with(str, suffix) return str:sub(-#suffix) == suffix end
+M.chain = function()
+    local bufnr = create_r_buffer()
+    if not bufnr then return end
 
 local function trim_lines(array)
     local result = {} -- Create a new table to store the trimmed lines
 
-    for i = 1, #array do
-        local line = array[i]
-        local trimmedLine = line:match("^%s*(.-)%s*$") -- Remove leading and trailing whitespace
-        table.insert(result, trimmedLine) -- Add the trimmed line to the result table
+    local tree = parser:parse()[1]
+    if not tree then return end
+
+    local root = tree:root()
+    local query = vim.treesitter.query.parse(
+        "r",
+        [[
+        (_
+            (binary_operator
+                lhs: (_)
+                operator: ([("|>") ("<-") ("+") ("special")]) 
+                rhs: (call) 
+            ) @pipeline_no_assign
+            (#not-has-parent? @pipeline_no_assign binary_operator)
+        )       
+  
+        (_
+            ; Handle when the pipeline is assignment to a variable
+            (binary_operator
+                lhs: (identifier) 
+                rhs: (binary_operator
+                    lhs: (_)
+                    operator: ([("|>") ("+") ("special")]) 
+                    rhs: (call)
+                ) @pipeline_with_assign
+            )
+        )
+        ]]
+    )
+
+    local cursor_row = vim.api.nvim_win_get_cursor(0)[1] - 1
+    local pipe_block_node
+
+    for _, node in query:iter_captures(root, bufnr, 0, -1) do
+        local start_row, _, end_row = node:range()
+        if cursor_row >= start_row and cursor_row <= end_row then
+            pipe_block_node = node
+            break
+        end
+    end
+
+    if not pipe_block_node then
+        inform("The cursor is not inside a piped expression.")
+        return
     end
 
-    return result
+    local call_query = vim.treesitter.query.parse(
+        "r",
+        [[
+        (_
+            (binary_operator
+                lhs: (_)
+                operator: (["|>" "+" "special"] @operator)
+                rhs: (call) @call
+                (#not-has-ancestor? @call call) ;; Ensure the rhs is not inside another call
+            )
+        )
+        ]]
+    )
+
+    local sibling = nil
+    local visited = false
+
+    for id, node, _ in call_query:iter_captures(pipe_block_node, bufnr, 0, -1) do
+        local capture_name = call_query.captures[id]
+        local start_row, _, end_row = node:range()
+
+        if
+            capture_name == "operator" and visited
+            or cursor_row == pipe_block_node:range()
+        then
+            sibling = node:prev_sibling()
+            break
+        elseif capture_name == "call" then
+            if cursor_row >= start_row and cursor_row <= end_row then visited = true end
+        end
+    end
+
+    local captured_node = sibling or pipe_block_node
+
+    M.source_lines({ vim.treesitter.get_node_text(captured_node, bufnr) }, nil)
 end
 
 -- Remove the <-, |>/%>% or + from the text