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.
    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.
  ]],
  ["rust-development"] = [[
    You are a coding assistant specialized in Rust development.
    You will receive a project’s context and user instructions related to Rust code.
	  Keep your suggestions aligned with Rust best practices and idiomatic Rust.
  ]],
  ["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:
    1. Analyse which files you need. Ask for file contents in YAML if needed.
    2. Request additional context outside YAML if necessary.
    3. When ready, provide final changes in YAML with:
       - 'project_name'
       - 'files', each having:
         * 'path'
         * 'diff' (for patching an existing file) OR 'content' (for a new file) OR 'delete'
    Important: do not provide entire file content for updates; instead provide a unified diff in 'diff'.
    Only modify or delete files whose contents you have explicitly requested and seen beforehand.
  ]],
  ["secure-coding"] = [[
    You are a coding assistant specialized in secure software development.
    Always consider security impacts. Use diffs for updates, new content for new files,
    and 'delete: true' for removals.
  ]],
  ["workflow-prompt"] = [[
    You are a coding assistant focusing on making the Neovim ChatGPT workflow straightforward and user-friendly.
    Remind the user to:
    - List needed files for further context
    - Request additional information outside YAML if needed
    - Provide final changes in YAML with 'project_name' and 'files', using:
      * 'diff' for existing file modifications
      * 'content' for new files
      * 'delete: true' for file deletions
  ]]
}

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 = 16384,
    project_name = "",
    debug = false,
    initial_files = {},
    preview_changes = false,
    interactive_file_selection = false,
    partial_acceptance = false,
    improved_debug = false,
    enable_chunking = false,
    enable_step_by_step = true,
    enable_debug_commands = false
  }

  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
        if type(result.preview_changes) == "boolean" then
          config.preview_changes = result.preview_changes
        end
        if type(result.interactive_file_selection) == "boolean" then
          config.interactive_file_selection = result.interactive_file_selection
        end
        if type(result.partial_acceptance) == "boolean" then
          config.partial_acceptance = result.partial_acceptance
        end
        if type(result.improved_debug) == "boolean" then
          config.improved_debug = result.improved_debug
        end
        if type(result.enable_chunking) == "boolean" then
          config.enable_chunking = result.enable_chunking
        end
        if type(result.enable_step_by_step) == "boolean" then
          config.enable_step_by_step = result.enable_step_by_step
        end
        if type(result.enable_debug_commands) == "boolean" then
          config.enable_debug_commands = result.enable_debug_commands
        end
      end
    end
  else
    config.initial_prompt = "You are a coding assistant who receives a project's context and user instructions..."
  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
      local combined_blocks = table.concat(merged_prompt, "\n\n")
      if config.initial_prompt ~= "" then
        config.initial_prompt = config.initial_prompt .. "\n\n" .. combined_blocks
      else
        config.initial_prompt = combined_blocks
      end
    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