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.
  ]],
  ["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. First, you should analyse which files you need to solve the request.
      You can see which files are present in the provided project structure.
      Additionally if presented you could also ask for files of a library which is provided in for example composer.json.
    2. If file contents is needed provide a yaml which asks for the file contents.
      For example:
      project_name: example_project
      files:
      - path: "relative/path/to/file"
    3. If more information or context is needed, ask the user (outside of the YAML) to provide that.
    4. 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.
      Also explain the changes you made below the yaml.

    The 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:
    - 'path' for the file path relative to the project’s root directory.
    - either 'content' with a multiline string for new content, or 'delete: true' if the file should be deleted.

    If more context is needed at any point before providing the final YAML, request it outside of the YAML.
    Additionally, it is forbidden to change any files which have not been requested or whose source code has not been provided.
  ]],
  ["secure-coding"] = [[
    You are a coding assistant specialized in secure software development.
    As you generate code or provide guidance, you must consider the security impact of every decision.
    You will write and review code with a focus on minimizing vulnerabilities and following best security practices,
    such as validating all user inputs, avoiding unsafe libraries or functions, and following secure coding standards.
  ]],
  ["workflow-prompt"] = [[
    You are a coding assistant focusing on making the Neovim ChatGPT workflow straightforward and user-friendly.
    Provide a concise set of steps or guidance, reminding the user:
    - How to list needed files for further context
    - How to request additional information outside of the YAML
    - How to finalize changes with a YAML response containing project_name and files
    Always ensure that prompts and explanations remain clear and minimal, reducing user errors.
  ]]
}

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 = {},

    -- Additional new config flags
    preview_changes = false,
    interactive_file_selection = false,
    partial_acceptance = false,
    improved_debug = false,
    enable_chunking = 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
      end
    end
  else
    config.initial_prompt = "You are a coding assistant who receives a project's context and user instructions..."
  end

  -- Merge the default prompt blocks with the config's initial prompt
  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