local M = {}
local uv = vim.loop

local ok_yaml, lyaml = pcall(require, "lyaml")

local prompt_blocks = {
  ["go-development"] = "You are a coding assistant specialized in Go development. You will receive a project’s context and user instructions related to Go code, and you must return the requested modifications or guidance. When returning modifications, follow the specified YAML structure. Keep your suggestions aligned with Go best practices and idiomatic Go.",
  ["typo3-development"] = "You are a coding assistant specialized in TYPO3 development. You have access to the project’s context and the user’s instructions. Your answers should focus on TYPO3 coding guidelines, extension development best practices, and TSconfig or TypoScript recommendations. When returning modifications, follow the YAML structure given.",
  ["basic-prompt"] = "You are a coding assistant who receives a project's context and user instructions. The user will provide a prompt, and you will guide them through a workflow:\n1. First, ask them which files from the project are needed to understand and perform the coding task.\n2. If more information or context is needed, ask the user (outside of the YAML) to provide that.\n3. When all necessary information is gathered, provide the final YAML with the project's name and a list of files to be created or modified.\n\nThe final YAML must have a top-level key named 'project_name' that matches the project's configured name, and a top-level key named 'files', which is a list of file changes. Each element in 'files' must be a mapping with:\n- 'path' for the file path relative to the project’s root directory.\n- either 'content' with a multiline string for new content, or 'delete: true' if the file should be deleted.\n\nIf more context is needed at any point before providing the final YAML, request it outside of the YAML.\n\nAdditionally, it is forbidden to change any files which have not been requested or whose source code has not been provided."
}

local function get_project_root()
  local current_file = vim.fn.expand("%:p")
  local root_dir

  if current_file == "" then
    root_dir = vim.fn.getcwd()
  else
    local file_dir = current_file:match("(.*)/")
    if not file_dir then
      root_dir = vim.fn.getcwd()
    else
      local cmd = string.format("cd %s && git rev-parse --show-toplevel 2>/dev/null", vim.fn.shellescape(file_dir))
      local git_root = vim.fn.systemlist(cmd)
      if vim.v.shell_error == 0 and git_root and #git_root > 0 then
        root_dir = git_root[1]
      else
        root_dir = file_dir
      end
    end
  end

  return root_dir
end

local function get_config_path()
  local root = get_project_root()
  return root .. "/.chatgpt_config.yaml"
end

function M.load()
  local path = get_config_path()
  local fd = uv.fs_open(path, "r", 438)
  local config = {
    initial_prompt = "",
    directories = { "." },
    default_prompt_blocks = {},
    token_limit = 128000,
    project_name = "",
    debug = false,
    initial_files = {}
  }

  if fd then
    local stat = uv.fs_fstat(fd)
    local data = uv.fs_read(fd, stat.size, 0)
    uv.fs_close(fd)
    if data and ok_yaml then
      local ok, result = pcall(lyaml.load, data)
      if ok and type(result) == "table" then
        if type(result.initial_prompt) == "string" then
          config.initial_prompt = result.initial_prompt
        end
        if type(result.directories) == "table" then
          config.directories = result.directories
        end
        if type(result.default_prompt_blocks) == "table" then
          config.default_prompt_blocks = result.default_prompt_blocks
        end
        if type(result.token_limit) == "number" then
          config.token_limit = result.token_limit
        end
        if type(result.project_name) == "string" then
          config.project_name = result.project_name
        end
        if type(result.debug) == "boolean" then
          config.debug = result.debug
        end
        if type(result.initial_files) == "table" then
          config.initial_files = result.initial_files
        end
      end
    end
  else
    config.initial_prompt = "You are a coding assistant who receives a project's context and user instructions. You will guide the user through a workflow:\n1. First, ask the user which files are needed from the project to understand and perform the coding task.\n2. If more information or context is needed, ask for it outside of the YAML.\n3. Once all information is obtained, return the final YAML with the project_name and the files to be created/modified or deleted.\n\nThe final YAML must have:\nproject_name: <project_name>\nfiles:\n  - path: \"relative/path/to/file\"\n    content: |\n      <file content>\n  - path: \"relative/path/to/other_file\"\n    delete: true\n\nIf more context is needed at any step before providing the final YAML, request it outside of the YAML."
  end

  if type(config.default_prompt_blocks) == "table" and #config.default_prompt_blocks > 0 then
    local merged_prompt = {}
    for _, block_name in ipairs(config.default_prompt_blocks) do
      if prompt_blocks[block_name] then
        table.insert(merged_prompt, prompt_blocks[block_name])
      end
    end
    if #merged_prompt > 0 then
      config.initial_prompt = table.concat(merged_prompt, "\n\n")
    end
  end

  if config.debug then
    vim.api.nvim_out_write("[chatgpt_nvim:config] Loaded config from: " .. path .. "\n")
    vim.api.nvim_out_write("[chatgpt_nvim:config] Debug logging is enabled.\n")
  end

  return config
end

return M