fix: claude cache control (#2279)

lua/avante/providers/claude.lua

@@ -50,6 +50,7 @@ end
 
 function M:is_disable_stream() return false end
 
+---@return AvanteClaudeMessage[]
 function M:parse_messages(opts)
   ---@type AvanteClaudeMessage[]
   local messages = {}
@@ -64,16 +65,8 @@ function M:parse_messages(opts)
 
   table.sort(messages_with_length, function(a, b) return a.length > b.length end)
 
-  ---@type table<integer, boolean>
-  local top_two = {}
-  if self.support_prompt_caching then
-    for i = 1, math.min(2, #messages_with_length) do
-      top_two[messages_with_length[i].idx] = true
-    end
-  end
-
   local has_tool_use = false
-  for idx, message in ipairs(opts.messages) do
+  for _, message in ipairs(opts.messages) do
     local content_items = message.content
     local message_content = {}
     if type(content_items) == "string" then
@@ -82,7 +75,6 @@ function M:parse_messages(opts)
         table.insert(message_content, {
           type = "text",
           text = content_items,
-          cache_control = top_two[idx] and { type = "ephemeral" } or nil,
         })
       end
     elseif type(content_items) == "table" then
@@ -90,15 +82,9 @@ function M:parse_messages(opts)
       for _, item in ipairs(content_items) do
         if type(item) == "string" then
           if message.role == "assistant" then item = item:gsub("%s+$", "") end
-          table.insert(
-            message_content,
-            { type = "text", text = item, cache_control = top_two[idx] and { type = "ephemeral" } or nil }
-          )
+          table.insert(message_content, { type = "text", text = item })
         elseif type(item) == "table" and item.type == "text" then
-          table.insert(
-            message_content,
-            { type = "text", text = item.text, cache_control = top_two[idx] and { type = "ephemeral" } or nil }
-          )
+          table.insert(message_content, { type = "text", text = item.text })
         elseif type(item) == "table" and item.type == "image" then
           table.insert(message_content, { type = "image", source = item.source })
         elseif not provider_conf.disable_tools and type(item) == "table" and item.type == "tool_use" then
@@ -386,10 +372,34 @@ function M:parse_curl_args(prompt_opts)
     end
   end
 
-  if self.support_prompt_caching and #tools > 0 then
-    local last_tool = vim.deepcopy(tools[#tools])
-    last_tool.cache_control = { type = "ephemeral" }
-    tools[#tools] = last_tool
+  if self.support_prompt_caching then
+    if #messages > 0 then
+      local found = false
+      for i = #messages, 1, -1 do
+        local message = messages[i]
+        message = vim.deepcopy(message)
+        ---@cast message AvanteClaudeMessage
+        local content = message.content
+        ---@cast content AvanteClaudeMessageContentTextItem[]
+        for j = #content, 1, -1 do
+          local item = content[j]
+          if item.type == "text" then
+            item.cache_control = { type = "ephemeral" }
+            found = true
+            break
+          end
+        end
+        if found then
+          messages[i] = message
+          break
+        end
+      end
+    end
+    if #tools > 0 then
+      local last_tool = vim.deepcopy(tools[#tools])
+      last_tool.cache_control = { type = "ephemeral" }
+      tools[#tools] = last_tool
+    end
   end
 
   return {
@@ -403,7 +413,7 @@ function M:parse_curl_args(prompt_opts)
         {
           type = "text",
           text = prompt_opts.system_prompt,
-          cache_control = { type = "ephemeral" },
+          cache_control = self.support_prompt_caching and { type = "ephemeral" } or nil,
         },
       },
       messages = messages,

lua/avante/types.lua

@@ -78,7 +78,7 @@ vim.g.avante_login = vim.g.avante_login
 ---@field on_messages_add? fun(messages: avante.HistoryMessage[]): nil
 ---@field on_state_change? fun(state: avante.GenerateState): nil
 ---
----@alias AvanteLLMMessageContentItem string | { type: "text", text: string } | { type: "image", source: { type: "base64", media_type: string, data: string } } | { type: "tool_use", name: string, id: string, input: any } | { type: "tool_result", tool_use_id: string, content: string, is_error?: boolean } | { type: "thinking", thinking: string, signature: string } | { type: "redacted_thinking", data: string }
+---@alias AvanteLLMMessageContentItem string | { type: "text", text: string, cache_control: { type: string } | nil } | { type: "image", source: { type: "base64", media_type: string, data: string } } | { type: "tool_use", name: string, id: string, input: any } | { type: "tool_result", tool_use_id: string, content: string, is_error?: boolean } | { type: "thinking", thinking: string, signature: string } | { type: "redacted_thinking", data: string }
 
 ---@alias AvanteLLMMessageContent AvanteLLMMessageContentItem[] | string
 
@@ -129,20 +129,20 @@ vim.g.avante_login = vim.g.avante_login
 ---@field role "user"
 ---@field parts { text: string }[]
 ---
----@class AvanteClaudeBaseMessage
+---@class AvanteClaudeMessageContentBaseItem
 ---@field cache_control {type: "ephemeral"}?
 ---
----@class AvanteClaudeTextMessage: AvanteClaudeBaseMessage
+---@class AvanteClaudeMessageContentTextItem: AvanteClaudeMessageContentBaseItem
 ---@field type "text"
 ---@field text string
 ---
----@class AvanteClaudeImageMessage: AvanteClaudeBaseMessage
+---@class AvanteClaudeMessageCotnentImageItem: AvanteClaudeMessageContentBaseItem
 ---@field type "image"
 ---@field source {type: "base64", media_type: string, data: string}
 ---
 ---@class AvanteClaudeMessage
 ---@field role "user" | "assistant"
----@field content [AvanteClaudeTextMessage | AvanteClaudeImageMessage][]
+---@field content [AvanteClaudeMessageContentTextItem | AvanteClaudeMessageCotnentImageItem][]
 
 ---@class AvanteClaudeTool
 ---@field name string