local M = {}
local uv = vim.loop

local ok_yaml, lyaml = pcall(require, "lyaml")
local prompts = require("chatgpt_nvim.prompts")

-- Determines the Git root or fallback directory.
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

-- Attempt to locate either .chatgpt_config.yaml or chatgpt_config.yaml, returning whichever exists first.
local function get_config_path()
  local root = get_project_root()
  local dot_config = root .. "/.chatgpt_config.yaml"
  local non_dot_config = root .. "/chatgpt_config.yaml"

  local dot_fd = uv.fs_open(dot_config, "r", 438)
  if dot_fd then
    uv.fs_close(dot_fd)
    return dot_config
  end

  local non_dot_fd = uv.fs_open(non_dot_config, "r", 438)
  if non_dot_fd then
    uv.fs_close(non_dot_fd)
    return non_dot_config
  end

  return nil
end

function M.load()
  -- Attempt to find either config file, else fallback
  local path = get_config_path()
  local config = {
    initial_prompt = "",
    directories = { "." },
    default_prompt_blocks = {},
    prompt_char_limit = 300000,
    project_name = "",
    debug = false,
    initial_files = {},
    include_file_contents = false, -- NEW FLAG: include file contents in prompt if true
    preview_changes = false,
    interactive_file_selection = false,
    partial_acceptance = false,
    improved_debug = false,
    enable_chunking = false,
    enable_step_by_step = true,

    -- If auto_lint is true, we only do LSP-based checks.
    auto_lint = false,

    tool_auto_accept = {
      read_file = false,
      edit_file = false,
      replace_in_file = false,
      executeCommand = false,
    }
  }

  -- If no config file found, alert user and return default config
  if not path then
    config.initial_prompt = "You are a coding assistant who receives a project's context and user instructions..."
    vim.notify(
      "No config file found (tried .chatgpt_config.yaml, chatgpt_config.yaml). Using defaults.",
      vim.log.levels.WARN
    )
    return config
  end

  local fd = uv.fs_open(path, "r", 438)
  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.prompt_char_limit) == "number" then
          config.prompt_char_limit = result.prompt_char_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.include_file_contents) == "boolean" then  -- LOAD NEW FLAG
          config.include_file_contents = result.include_file_contents
        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.auto_lint) == "boolean" then
          config.auto_lint = result.auto_lint
        end

        if type(result.tool_auto_accept) == "table" then
          for k, v in pairs(result.tool_auto_accept) do
            if config.tool_auto_accept[k] ~= nil and type(v) == "boolean" then
              config.tool_auto_accept[k] = v
            end
          end
        end
      end
    end
  else
    config.initial_prompt = "You are a coding assistant who receives a project's context and user instructions..."
  end

  -- Merge default prompt blocks
  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 prompts[block_name] then
        table.insert(merged_prompt, prompts[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

  -- Include project name in the final initial prompt, if set
  if config.project_name ~= "" then
    config.initial_prompt =
      "[Project Name: " .. config.project_name .. "]\n\n" .. config.initial_prompt
  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