require 'rails_helper'

RSpec.describe 'Counts table API', type: :request do
  include_context 'Ainu locale'

  let!(:actor) { create(:user, :member, name: 'Counts actor') }
  let!(:record) { create(:post) }
  let!(:tag) { create(:tag, primary_name: 'alpha', category: :general) }
  let!(:external) { create(:external_tag, name: 'beta') }
  let(:point) { '2025-01-01T00:00:00Z' }
  let(:base) do
    { resource: 'posts', definition: 'history', mode: 'details',
      execution_at: point, timezone: 'UTC', locale: 'ja' }
  end

  before do
    TagVersion.create!(tag:, version_no: 1, event_type: 'create', name: 'alpha',
        category: 'general', aliases: '', parent_tag_ids: '',
        names: { ja: { name: 'alpha', script_code: 'Jpan', auto_generated: false,  aliases: [] } },
        created_at: Time.utc(2023))
    NicoTagVersion.create!(external_tag: external, version_no: 1,
        event_type: 'create', name: 'beta', linked_tags: '', created_at: Time.utc(2023))
    snapshots = [
        { tag_id: tag.id, version_no: 1, name: 'alpha', category: 'general', sections: [] },
        { external_tag_id: external.id }]
    [1, 2, 3].each do |number|
      PostVersion.create!(post: record, version_no: number,
          event_type: number == 1 ? 'create' : 'update', url: record.url,
          title: "snapshot #{ number }", tags: '', parent_post_ids: '',
          tags_json: snapshots.first(number == 1 ? 2 : (number == 2 ? 1 : 0)),
          created_by_user: number == 3 ? nil : actor,
          created_at: Time.utc(2024, 1, 31, 15) + (number - 1).hours)
    end
  end

  def query(extra = {})
    get '/counts/query', params: base.merge(extra)
    expect(response).to have_http_status(:ok)
    response.parsed_body
  end

  def axis(field, value, type: 'string', grain: nil, root: 'conditions')
    result = { root => '', "#{ root }.0.field" => field,
               "#{ root }.0.value_type" => type }
    result["#{ root }.0.operator"] = 'axis_eq' if root == 'conditions'
    result["#{ root }.0.value"] = value unless type == 'null'
    result["#{ root }.0.grain"] = grain if grain
    result
  end

  def versions(result) = result.fetch('versions').map { _1.fetch('version_no') }

  it 'separates latest and history and defaults to stable detail ordering and limit 100' do
    history = query
    expect(versions(history)).to eq([1, 2, 3])
    expect(history).to include('limit' => 100, 'count' => 3, 'output_count' => 3,
        'visible_output_count' => 3, 'excluded_count' => 0)
    expect(history['versions'].map { _1['latest'] }).to eq([false, false, true])
    expect(versions(query(definition: 'latest'))).to eq([3])
    expect(versions(query(limit: 1, page: 2))).to eq([2])
    expect(versions(query(sort: 'version_no:desc', limit: 1))).to eq([3])
  end

  it 'counts regular pivot rows separately from totals and from underlying records' do
    total = query(mode: 'summary', rows: '', cols: '')
    expect(total).to include('count' => 3, 'output_count' => 1, 'group_count' => 1)
    expect(total['cells']).to eq([{ 'values' => [], 'count' => 3 }])
    pivot = query(mode: 'summary', rows: 'event_type', cols: '', sort: '', limit: 1)
    expect(pivot).to include('group_count' => 2, 'visible_output_count' => 2)
    expect(pivot['row_headers'].count { _1['kind'] == 'data' }).to eq(1)
    expect(pivot['row_headers']).to include(hash_including('kind' => 'grand_total'))
    expect(query(mode: 'summary', rows: '', cols: 'event_type', sort: '')['output_count']).to eq(1)
  end

  it 'preserves timezone, NULL and legacy drill semantics and permits condition removal' do
    month = axis('created_at', '2024-02', grain: 'month')
    expect(versions(query(month.merge(timezone: 'Asia/Tokyo')))).to eq([1, 2, 3])
    expect(versions(query(month))).to eq([])
    old = axis('created_at', '2024-02', grain: 'month', root: 'drill')
    expect(versions(query(old.merge(timezone: 'Asia/Tokyo')))).to eq([1, 2, 3])
    expect(versions(query(old.merge(month).merge(timezone: 'Asia/Tokyo')))).to eq([1, 2, 3])
    expect(versions(query(axis('user', nil, type: 'null')))).to eq([3])
    expect(versions(query(axis('changed_field', 'title')))).to eq([2, 3])
    expect(versions(query)).to eq([1, 2, 3])
  end

  it 'evaluates latest before filtering the version set' do
    predicate = { conditions: '', 'conditions.0.field' => 'latest',
                  'conditions.0.operator' => 'eq', 'conditions.0.value' => 'false' }
    expect(versions(query(predicate))).to eq([1, 2])
    expect(versions(query(predicate.merge('conditions.0.value' => 'true')))).to eq([3])
  end

  it 'keeps ANY, ALL and NONE distinct without multiplying parent records' do
    values = { conditions: '', 'conditions.0.field' => 'tags',
               'conditions.0.values' => '1', condition_values: '',
               'condition_values.0.condition' => '0',
               'condition_values.0.value_type' => 'string',
               'condition_values.0.value' => "internal:#{ tag.id }",
               'condition_values.1.condition' => '0',
               'condition_values.1.value_type' => 'string',
               'condition_values.1.value' => "external:#{ external.id }" }
    { 'any' => [1, 2], 'all' => [1], 'none' => [3] }.each do |operator, expected|
      expect(versions(query(values.merge('conditions.0.operator' => operator)))).to eq(expected)
    end
    result = query(axis('tags', "internal:#{ tag.id }"))
    expect(result['versions'].first['tags'].length).to eq(2)
  end

  it 'distinguishes IN, NOT IN, an empty selection and an unspecified selection' do
    predicate = { conditions: '', 'conditions.0.field' => 'version_no',
                  'conditions.0.operator' => 'in', 'conditions.0.values' => '1',
                  condition_values: '', 'condition_values.0.condition' => '0',
                  'condition_values.0.value_type' => 'number',
                  'condition_values.0.value' => '1' }
    expect(versions(query(predicate))).to eq([1])
    expect(versions(query(predicate.merge('conditions.0.operator' => 'not_in')))).to eq([2, 3])
    empty = predicate.reject { |key, _value| key.to_s.start_with?('condition_values.') }
    expect(versions(query(empty))).to be_empty
    expect(versions(query(empty.except('conditions.0.values')))).to eq([1, 2, 3])
  end

  it 'canonicalises unreferenced tags while preserving partial stable references' do
    reference = { tag_refs: '', 'tag_refs.0.name' => 'alpha',
                  'tag_refs.0.tag_id' => tag.id.to_s }
    expect(versions(query(tags: 'alpha'))).to eq([1, 2])
    expect(versions(query(reference.merge(tags: 'alpha nico:beta')))).to eq([1])
    expect(versions(query(reference.merge(tags: 'nico:beta alpha')))).to eq([1])
    expect(versions(query(reference.merge(tags: 'alpha not:nico:beta')))).to eq([2])
    expect(versions(query(reference.merge(tags: 'alpha nico:beta', match: 'any')))).to eq([1, 2])
    expect(versions(query(tags: 'not:alpha'))).to eq([3])
    get '/counts/query', params: base.merge(reference).merge(tags: 'different')
    expect(response).to have_http_status(:bad_request)
  end

  it 'rejects malformed structured conditions and axes without accepting arbitrary SQL' do
    [
        { rows: '[{"field":"user"}]' }, { rows: 'user user' },
        { rows: 'user:month' }, { rows: 'password' }, { limit: 101 }, { limit: 0 },
        { page: '1x' }, { conditions: 'eyJmaWVsZCI6InVzZXIifQ==' },
        { conditions: '', 'conditions.1.field' => 'user' },
        axis('password', '1'), axis('changed_field', 'title').merge(definition: 'latest'),
        axis('user', 'yes', type: 'boolean'),
        { conditions: '', 'conditions.0.field' => 'title',
          'conditions.0.operator' => 'eq', 'conditions.0.value' => 'x' * 8193 }].each do |invalid|
      get '/counts/query', params: base.merge(invalid)
      expect(response).to have_http_status(:bad_request), invalid.inspect
    end
  end

  it 'rejects duplicate URL keys and JSON query payloads at the HTTP boundary' do
    ['resource=posts&limit=20&limit=50', 'resource=posts&headers=%5B%22Id.%22%5D',
     'resource=posts&limit%5B%5D=20'].each do |query_string|
      get "/counts/query?#{ query_string }"
      expect(response).to have_http_status(:bad_request)
    end
  end

  it 'reports column overflow separately from malformed input' do
    101.times do |index|
      PostVersion.create!(post: record, version_no: index + 4,
          event_type: 'update', url: record.url, title: "column #{ index }",
          tags: '', tags_json: [], parent_post_ids: '', created_at: Time.utc(2024, 3))
    end
    get '/counts/query', params: base.merge(mode: 'summary', rows: '', cols: 'title', sort: '')
    expect(response).to have_http_status(:unprocessable_entity)
    expect(response.parsed_body).to eq('error' => 'too_many_columns', 'max_columns' => 100)
  end

  it 'defines all six resources with filterable output fields and shared detail defaults' do
    locale
    CountsResourceDefinition::DEFINITIONS.each_key do |resource|
      get "/counts/definitions/#{ resource }", params: { locale: 'ain-Kana' }
      expect(response).to have_http_status(:ok)
      body = response.parsed_body
      filters = body['filter_fields'].map { _1['key'] }
      walk = lambda do |fields, prefix|
        fields.each do |field|
          key = [prefix, field['key']].compact.join('.')
          expect(filters).to include(key)
          walk.call(field.fetch('children', []), key)
        end
      end
      walk.call(body['output_fields'], nil)
      defaults = body['defaults'].select { _1['mode'] == 'details' }
      expect(defaults.map { _1['definition'] }).to eq(['latest', 'history'])
      expect(defaults.first['params']).to eq(defaults.last['params'])
      settings = defaults.first['params'].to_h { [_1['key'], _1['value']] }
      expect(settings['sort']).to eq('resource_id:asc version_no:asc')
      if resource == 'posts'
        expect(settings['children'].split).to eq(['tags.name_ain', 'parents.id'])
      end
      keys = body['name_columns'].map { _1['key'] }
      languages = Language.order(:created_at, :code).pluck(:code)
      expect(keys).to eq(languages.map { "name_#{ _1 }" } + languages.map { "aliases_#{ _1 }" })
    end
  end

  [nil, :guest, :member, :admin].each do |role|
    context "authority #{ role || 'anonymous' }" do
      before do
        sign_in_as(create(:user, role)) if role
        # Equal timestamps deliberately require version ordering, not a date comparison.
        ['discard', 'restore', 'discard', 'restore'].each_with_index do |event, index|
          PostVersion.create!(post: record, version_no: index + 4, event_type: event,
              url: record.url, title: event == 'restore' ? 'restored' : 'private snapshot',
              tags: '', tags_json: [], parent_post_ids: '', created_at: Time.utc(2024, 3))
        end
      end

      it 'keeps every earlier discard boundary private but counts denied records' do
        result = query
        expected = role == :admin ? (1..7).to_a : [7]
        expect(versions(result)).to eq(expected)
        expect(result).to include('output_count' => 7,
            'visible_output_count' => expected.length, 'excluded_count' => 7 - expected.length)
        expect(response.headers['Cache-Control']).to include('no-store')
        expect(response.body).not_to include('private snapshot') unless role == :admin
      end

      it 'applies the same version boundary to the ordinary history endpoint and old values' do
        get '/posts/versions', params: { post: record.id, locale: 'ja' }
        expect(response).to have_http_status(:ok)
        rows = response.parsed_body.fetch('versions')
        expect(rows.map { _1['version_no'] }).to eq(role == :admin ? (1..7).to_a.reverse : [7])
        unless role == :admin
          expect(rows.sole.dig('title', 'prev')).to be_nil
          expect(response.body).not_to include('private snapshot')
        end
      end

      it 'does not resolve private condition names even when the result set is empty' do
        TagVersion.create!(tag:, version_no: 2, event_type: 'discard', name: 'secret tag',
            category: 'general', aliases: '', parent_tag_ids: '',
            names: { ja: { name: 'secret tag', script_code: 'Jpan', aliases: [] } },
            created_at: Time.utc(2024, 2))
        result = query(axis('tags', "internal:#{ tag.id }").merge(definition: 'latest'))
        expect(result['versions']).to be_empty
        expected = role == :admin ? { "internal:#{ tag.id }" => 'secret tag' } : {}
        expect(result['condition_labels']['tags']).to eq(expected)
        get '/counts/definitions/posts/candidates', params: {
            field: 'tags', query: 'secret', execution_at: point, locale: 'ja' }
        expect(response).to have_http_status(:ok)
        expect(response.parsed_body['rows']).to be_empty
      end
    end
  end
end