defmodule BDS.AI.ChatTools do
  @moduledoc false

  import Ecto.Query

  alias BDS.AI.Chat
  alias BDS.Media.Media
  alias BDS.MCP.Queries
  alias BDS.Posts.Post
  alias BDS.Projects.Project
  alias BDS.Repo
  alias BDS.Search

  @spec execute(String.t(), map(), String.t() | nil) :: map()
  def execute("blog_stats", _arguments, project_id) do
    project_id = project_id || active_project_id()

    %{
      post_count:
        Repo.aggregate(from(post in Post, where: post.project_id == ^project_id), :count, :id),
      media_count:
        Repo.aggregate(from(media in Media, where: media.project_id == ^project_id), :count, :id),
      tag_count: Chat.count_distinct_string_list(Post, :tags, project_id),
      category_count: Chat.count_distinct_string_list(Post, :categories, project_id)
    }
  end

  def execute("check_term", arguments, project_id) do
    project_id = project_id || active_project_id()
    term = normalize_term(arguments["term"])

    posts = Repo.all(from post in Post, where: post.project_id == ^project_id)

    tag_post_count =
      Enum.count(posts, fn post ->
        Enum.any?(post.tags || [], &(normalize_term(&1) == term))
      end)

    category_post_count =
      Enum.count(posts, fn post ->
        Enum.any?(post.categories || [], &(normalize_term(&1) == term))
      end)

    %{
      is_category: category_post_count > 0,
      category_post_count: category_post_count,
      is_tag: tag_post_count > 0,
      tag_post_count: tag_post_count
    }
  end

  def execute("search_posts", arguments, project_id) do
    project_id = project_id || active_project_id()
    filters = search_filters(arguments)

    {:ok, result} = Search.search_posts(project_id, arguments["query"] || "", filters)

    %{
      posts: Enum.map(result.posts, &Queries.post_summary/1),
      total: result.total,
      offset: result.offset,
      limit: result.limit,
      has_more: result.offset + result.limit < result.total
    }
  end

  def execute("read_post_by_slug", arguments, project_id) do
    project_id = project_id || active_project_id()

    case Repo.get_by(Post, project_id: project_id, slug: arguments["slug"]) do
      %Post{} = post -> %{post: Queries.post_detail(post)}
      nil -> %{error: "not_found"}
    end
  end

  def execute("list_posts", arguments, project_id) do
    project_id = project_id || active_project_id()
    limit = normalize_limit(arguments["limit"])
    offset = normalize_offset(arguments["offset"])
    filters = search_filters(arguments) |> Map.merge(%{limit: limit, offset: offset})

    {:ok, result} = Search.search_posts(project_id, "", filters)

    %{
      posts:
        Enum.map(result.posts, fn post ->
          post
          |> Queries.post_summary()
          |> Map.put("url", "/posts/#{post.slug}")
          |> Map.put("updated_at", post.updated_at)
        end),
      total: result.total,
      offset: result.offset,
      limit: result.limit,
      has_more: result.offset + result.limit < result.total
    }
  end

  def execute("list_media", arguments, project_id) do
    project_id = project_id || active_project_id()
    limit = normalize_limit(arguments["limit"])

    Repo.all(
      from(media in Media,
        where: media.project_id == ^project_id,
        order_by: [desc: media.updated_at],
        limit: ^limit,
        select: %{
          id: media.id,
          title: media.title,
          mime_type: media.mime_type,
          filename: media.filename,
          updated_at: media.updated_at
        }
      )
    )
  end

  def execute("list_tags", _arguments, project_id) do
    project_id = project_id || active_project_id()

    %{
      tags: counted_terms(project_id, :tags),
      count: length(counted_terms(project_id, :tags))
    }
  end

  def execute("list_categories", _arguments, project_id) do
    project_id = project_id || active_project_id()

    %{
      categories: counted_terms(project_id, :categories),
      count: length(counted_terms(project_id, :categories))
    }
  end

  def execute("count_posts", arguments, project_id) do
    project_id = project_id || active_project_id()
    group_by = List.wrap(arguments["groupBy"] || arguments["group_by"]) |> Enum.map(&to_string/1)
    {:ok, result} = Search.search_posts(project_id, "", search_filters(arguments))

    groups =
      result.posts
      |> Enum.flat_map(&Queries.group_rows(&1, group_by))
      |> Enum.group_by(& &1, fn _row -> 1 end)
      |> Enum.map(fn {row, counts} -> Map.put(row, "count", length(counts)) end)
      |> Enum.sort_by(&Map.to_list/1)

    %{groups: groups, total_posts: result.total}
  end

  def execute("render_table", arguments, _project_id) do
    %{
      type: "table",
      title: arguments["title"],
      columns: arguments["columns"] || [],
      rows: arguments["rows"] || []
    }
  end

  def execute("render_chart", arguments, _project_id) do
    %{
      type: "chart",
      title: arguments["title"],
      chart_type: arguments["chart_type"] || "bar",
      series: arguments["series"] || []
    }
  end

  def execute("render_form", arguments, _project_id) do
    %{
      type: "form",
      title: arguments["title"],
      fields: arguments["fields"] || [],
      submit_label: arguments["submit_label"] || arguments["submitLabel"],
      submit_action: arguments["submit_action"] || arguments["submitAction"]
    }
  end

  def execute("render_card", arguments, _project_id) do
    %{
      type: "card",
      title: arguments["title"],
      subtitle: arguments["subtitle"],
      body: arguments["body"],
      actions: arguments["actions"] || []
    }
  end

  def execute("render_metric", arguments, _project_id) do
    %{
      type: "metric",
      label: arguments["label"],
      value: arguments["value"]
    }
  end

  def execute("render_list", arguments, _project_id) do
    %{
      type: "list",
      title: arguments["title"],
      items: arguments["items"] || []
    }
  end

  def execute("render_tabs", arguments, _project_id) do
    %{
      type: "tabs",
      title: arguments["title"],
      tabs: arguments["tabs"] || []
    }
  end

  def execute("render_mindmap", arguments, _project_id) do
    %{
      type: "mindmap",
      title: arguments["title"],
      nodes: arguments["nodes"] || []
    }
  end

  def execute(name, _arguments, _project_id) do
    %{error: "unknown_tool", name: name}
  end

  @spec available_specs(String.t() | nil, map()) :: [map()]
  def available_specs(project_id, capabilities) do
    if capabilities.supports_tool_calls do
      project_tools =
        if is_binary(project_id) do
          [
            %{
              name: "blog_stats",
              spec:
                tool_spec("blog_stats", "Return aggregate blog statistics", %{
                  "type" => "object",
                  "properties" => %{}
                })
            },
            %{
              name: "check_term",
              spec:
                tool_spec(
                  "check_term",
                  "Check whether a term exists as a category, tag, or both. Returns post counts for each. Use before search_posts or list_posts when unsure whether a term is a category or tag.",
                  %{
                    "type" => "object",
                    "properties" => %{"term" => %{"type" => "string"}},
                    "required" => ["term"]
                  }
                )
            },
            %{
              name: "search_posts",
              spec:
                tool_spec(
                  "search_posts",
                  "Search blog posts using full-text search. Can filter by category, tags, language, missing translation language, year, month, or status. Returns paginated concrete post data with titles, slugs, tags, categories, backlinks, and links_to.",
                  post_search_schema(true)
                )
            },
            %{
              name: "read_post_by_slug",
              spec:
                tool_spec(
                  "read_post_by_slug",
                  "Read full content and metadata of a specific blog post by slug. Includes backlinks, links_to, tags, categories, excerpt, status, language, and available languages.",
                  %{
                    "type" => "object",
                    "properties" => %{"slug" => %{"type" => "string"}},
                    "required" => ["slug"]
                  }
                )
            },
            %{
              name: "list_posts",
              spec:
                tool_spec(
                  "list_posts",
                  "List blog posts with optional filtering by status, category, tags, language, year, or month. Returns paginated concrete post data with titles, slugs, URLs, statuses, tags, categories, backlinks, and links_to. Use for recent, latest, top, or title-list requests.",
                  post_search_schema(false)
                )
            },
            %{
              name: "list_media",
              spec:
                tool_spec(
                  "list_media",
                  "List concrete media data in the active project, including titles, filenames, MIME types, and update times.",
                  limit_schema()
                )
            },
            %{
              name: "list_tags",
              spec:
                tool_spec(
                  "list_tags",
                  "List all tags used across blog posts with post counts.",
                  %{
                    "type" => "object",
                    "properties" => %{}
                  }
                )
            },
            %{
              name: "list_categories",
              spec:
                tool_spec(
                  "list_categories",
                  "List all categories used across blog posts with post counts.",
                  %{"type" => "object", "properties" => %{}}
                )
            },
            %{
              name: "count_posts",
              spec:
                tool_spec(
                  "count_posts",
                  "Count posts grouped by dimensions such as year, month, tag, category, or status. Use for analytics, distributions, and heat maps without transferring full post content.",
                  count_posts_schema()
                )
            }
          ]
        else
          []
        end

      project_tools ++
        [
          %{
            name: "render_card",
            spec:
              tool_spec("render_card", "Return a structured card payload", render_card_schema())
          },
          %{
            name: "render_table",
            spec:
              tool_spec(
                "render_table",
                "Return a structured table payload",
                render_table_schema()
              )
          },
          %{
            name: "render_chart",
            spec:
              tool_spec(
                "render_chart",
                "Return a structured chart payload",
                render_chart_schema()
              )
          },
          %{
            name: "render_form",
            spec:
              tool_spec("render_form", "Return a structured form payload", render_form_schema())
          },
          %{
            name: "render_metric",
            spec:
              tool_spec(
                "render_metric",
                "Return a structured metric payload",
                render_metric_schema()
              )
          },
          %{
            name: "render_list",
            spec:
              tool_spec("render_list", "Return a structured list payload", render_list_schema())
          },
          %{
            name: "render_tabs",
            spec:
              tool_spec("render_tabs", "Return a structured tabs payload", render_tabs_schema())
          },
          %{
            name: "render_mindmap",
            spec:
              tool_spec(
                "render_mindmap",
                "Return a structured mindmap payload",
                render_mindmap_schema()
              )
          }
        ]
    else
      []
    end
  end

  defp tool_spec(name, description, parameters) do
    %{
      "type" => "function",
      "function" => %{
        "name" => name,
        "description" => description,
        "parameters" => parameters
      }
    }
  end

  defp limit_schema do
    %{
      "type" => "object",
      "properties" => %{
        "limit" => %{"type" => "integer", "minimum" => 1, "maximum" => 50}
      }
    }
  end

  defp post_search_schema(require_query) do
    schema = %{
      "type" => "object",
      "properties" => %{
        "query" => %{"type" => "string"},
        "status" => %{"type" => "string", "enum" => ["draft", "published", "archived"]},
        "category" => %{"type" => "string"},
        "tags" => %{"type" => "array", "items" => %{"type" => "string"}},
        "language" => %{"type" => "string"},
        "missingTranslationLanguage" => %{"type" => "string"},
        "year" => %{"type" => "integer"},
        "month" => %{"type" => "integer", "minimum" => 1, "maximum" => 12},
        "limit" => %{"type" => "integer", "minimum" => 1, "maximum" => 50},
        "offset" => %{"type" => "integer", "minimum" => 0}
      }
    }

    if require_query, do: Map.put(schema, "required", ["query"]), else: schema
  end

  defp count_posts_schema do
    %{
      "type" => "object",
      "properties" => %{
        "groupBy" => %{
          "type" => "array",
          "items" => %{
            "type" => "string",
            "enum" => ["year", "month", "tag", "category", "status"]
          }
        },
        "year" => %{"type" => "integer"},
        "month" => %{"type" => "integer", "minimum" => 1, "maximum" => 12},
        "status" => %{"type" => "string", "enum" => ["draft", "published", "archived"]},
        "category" => %{"type" => "string"},
        "tags" => %{"type" => "array", "items" => %{"type" => "string"}}
      },
      "required" => ["groupBy"]
    }
  end

  defp render_table_schema do
    %{
      "type" => "object",
      "properties" => %{
        "title" => %{"type" => "string"},
        "columns" => %{"type" => "array"},
        "rows" => %{"type" => "array"}
      }
    }
  end

  defp render_chart_schema do
    %{
      "type" => "object",
      "properties" => %{
        "title" => %{"type" => "string"},
        "chart_type" => %{"type" => "string"},
        "series" => %{"type" => "array"}
      }
    }
  end

  defp render_form_schema do
    %{
      "type" => "object",
      "properties" => %{
        "title" => %{"type" => "string"},
        "fields" => %{"type" => "array"},
        "submitLabel" => %{"type" => "string"},
        "submitAction" => %{"type" => "string"}
      }
    }
  end

  defp render_card_schema do
    %{
      "type" => "object",
      "properties" => %{
        "title" => %{"type" => "string"},
        "subtitle" => %{"type" => "string"},
        "body" => %{"type" => "string"},
        "actions" => %{"type" => "array"}
      }
    }
  end

  defp render_metric_schema do
    %{
      "type" => "object",
      "properties" => %{
        "label" => %{"type" => "string"},
        "value" => %{"type" => "string"}
      }
    }
  end

  defp render_list_schema do
    %{
      "type" => "object",
      "properties" => %{
        "title" => %{"type" => "string"},
        "items" => %{"type" => "array"}
      }
    }
  end

  defp render_tabs_schema do
    %{
      "type" => "object",
      "properties" => %{
        "title" => %{"type" => "string"},
        "tabs" => %{"type" => "array"}
      }
    }
  end

  defp render_mindmap_schema do
    %{
      "type" => "object",
      "properties" => %{
        "title" => %{"type" => "string"},
        "nodes" => %{"type" => "array"}
      }
    }
  end

  defp normalize_limit(value) when is_integer(value) and value > 0 and value <= 50, do: value
  defp normalize_limit(_value), do: 10

  defp normalize_offset(value) when is_integer(value) and value >= 0, do: value
  defp normalize_offset(_value), do: 0

  defp search_filters(arguments) do
    %{}
    |> maybe_put(:category, arguments["category"])
    |> maybe_put(:tags, arguments["tags"])
    |> maybe_put(:language, arguments["language"])
    |> maybe_put(:missing_translation_language, arguments["missingTranslationLanguage"])
    |> maybe_put(:year, arguments["year"])
    |> maybe_put(:month, arguments["month"])
    |> maybe_put(:status, BDS.BoundedAtoms.post_status(arguments["status"]))
    |> Map.put(:offset, normalize_offset(arguments["offset"]))
    |> Map.put(:limit, normalize_limit(arguments["limit"]))
  end

  defp maybe_put(map, _key, nil), do: map
  defp maybe_put(map, _key, ""), do: map
  defp maybe_put(map, key, value), do: Map.put(map, key, value)

  defp counted_terms(project_id, field) do
    Repo.all(
      from post in Post, where: post.project_id == ^project_id, select: field(post, ^field)
    )
    |> List.flatten()
    |> Enum.reject(&blank?/1)
    |> Enum.frequencies()
    |> Enum.map(fn {term, count} -> %{name: term, count: count} end)
    |> Enum.sort_by(&String.downcase(to_string(&1.name)))
  end

  defp blank?(value), do: is_nil(value) or String.trim(to_string(value)) == ""

  defp normalize_term(value), do: value |> to_string() |> String.downcase()

  defp active_project_id do
    Repo.one(from(project in Project, where: project.is_active == true, select: project.id))
  end
end