Feat: Add Amazon Bedrock provider (#1167)

lua/avante/providers/bedrock/claude.lua

@@ -0,0 +1,73 @@
+---@class AvanteBedrockClaudeTextMessage
+---@field type "text"
+---@field text string
+---
+---@class AvanteBedrockClaudeMessage
+---@field role "user" | "assistant"
+---@field content [AvanteBedrockClaudeTextMessage][]
+
+---@class AvanteBedrockModelHandler
+local M = {}
+
+M.role_map = {
+  user = "user",
+  assistant = "assistant",
+}
+
+M.parse_messages = function(opts)
+  ---@type AvanteBedrockClaudeMessage[]
+  local messages = {}
+
+  for _, message in ipairs(opts.messages) do
+    table.insert(messages, {
+      role = M.role_map[message.role],
+      content = {
+        {
+          type = "text",
+          text = message.content,
+        },
+      },
+    })
+  end
+
+  return messages
+end
+
+M.parse_response = function(ctx, data_stream, event_state, opts)
+  if event_state == nil then
+    if data_stream:match('"content_block_delta"') then
+      event_state = "content_block_delta"
+    elseif data_stream:match('"message_stop"') then
+      event_state = "message_stop"
+    end
+  end
+  if event_state == "content_block_delta" then
+    local ok, json = pcall(vim.json.decode, data_stream)
+    if not ok then return end
+    opts.on_chunk(json.delta.text)
+  elseif event_state == "message_stop" then
+    opts.on_complete(nil)
+    return
+  elseif event_state == "error" then
+    opts.on_complete(vim.json.decode(data_stream))
+  end
+end
+
+---@param prompt_opts AvantePromptOptions
+---@param body_opts table
+---@return table
+M.build_bedrock_payload = function(prompt_opts, body_opts)
+  local system_prompt = prompt_opts.system_prompt or ""
+  local messages = M.parse_messages(prompt_opts)
+  local max_tokens = body_opts.max_tokens or 2000
+  local temperature = body_opts.temperature or 0.7
+  local payload = {
+    anthropic_version = "bedrock-2023-05-31",
+    max_tokens = max_tokens,
+    messages = messages,
+    system = system_prompt,
+  }
+  return vim.tbl_deep_extend("force", payload, body_opts or {})
+end
+
+return M