;;; ebox-fixtures.el --- Typed Ebox test fixtures -*- lexical-binding: t; -*-

;;; Commentary:
;; Test-only construction helpers.  They keep retained layout, publication,
;; and rollback tests on the canonical Text/Box/LayoutConfig model without
;; reintroducing removed public constructors.

;;; Code:

(require 'cl-lib)
(require 'ebox)

(defconst ebox-test--source-fields
  '(:source-identity :key :class :id
    :selector-state :selector-attributes)
  "Author source fields owned by opaque fixture source handles.")

(defconst ebox-test--direct-fields
  '(:region-id :surface-properties :scroll-offset
    :ebox-scroll-offset-controlled-p)
  "Private runtime fields used only by focused backend tests.")

(defconst ebox-test--non-style-fields
  (append ebox-test--source-fields
          '(:outer :item-gap :cross-align)
          ebox-test--direct-fields)
  "Fixture fields that do not enter the canonical Ebox style schema.")

(defun ebox-test-root (input)
  "Return the single canonical root owned by fixture INPUT."
  (ebox-canonical-input--single-root input "Ebox test fixture"))

(defun ebox-test-forest (input)
  "Return fixture INPUT's ordered canonical forest."
  (unless (ebox-canonical-input-p input)
    (signal 'wrong-type-argument (list 'ebox-canonical-input-p input)))
  (copy-sequence (ebox-canonical-input--nodes input)))

(defun ebox-test-source-index (input)
  "Return the immutable source generation owned by fixture INPUT."
  (unless (ebox-canonical-input-p input)
    (signal 'wrong-type-argument (list 'ebox-canonical-input-p input)))
  (ebox-canonical-input--source-index input))

(defun ebox-test-child-range (range-ref &rest inputs)
  "Return a test Range descriptor over canonical INPUTS.
The descriptor is consumed only by a fixture parent, which imports every input
source generation before lowering the descriptor to raw canonical nodes."
  (unless range-ref
    (error "Ebox test Range ref must be non-nil"))
  (dolist (input inputs)
    (unless (ebox-canonical-input-p input)
      (signal 'wrong-type-argument (list 'ebox-canonical-input-p input))))
  (ebox-child-range--descriptor-create range-ref inputs))

(defun ebox-test-forest-input (&rest inputs)
  "Combine canonical INPUTS into one ordered forest input."
  (let ((builder (ebox-source-builder-create))
        nodes)
    (dolist (input inputs)
      (unless (ebox-canonical-input-p input)
        (signal 'wrong-type-argument (list 'ebox-canonical-input-p input)))
      (ebox-source-builder-import builder (ebox-test-source-index input))
      (setq nodes (nconc nodes (ebox-test-forest input))))
    (ebox-canonical-input-create nodes (ebox-source-builder-finish builder))))

(defun ebox-test--keep (plist keys)
  "Return PLIST entries whose keys occur in KEYS."
  (cl-loop for (key value) on plist by #'cddr
           when (memq key keys) append (list key value)))

(defun ebox-test--split-items (items)
  "Return `(PROPERTIES . CHILDREN)' from evaluated fixture ITEMS."
  (let (properties children)
    (while items
      (let ((item (pop items)))
        (if (keywordp item)
            (progn
              (unless items (error "Missing fixture value for %S" item))
              (setq properties
                    (append properties (list item (pop items)))))
          (push item children))))
    (cons properties (nreverse children))))

(defun ebox-test--without (plist keys)
  "Return PLIST without entries whose keys occur in KEYS."
  (cl-loop for (key value) on plist by #'cddr
           unless (memq key keys) append (list key value)))

(defun ebox-test--source-handle (builder props declarations)
  "Return one opaque fixture source for PROPS and DECLARATIONS.
The optional `:source-identity' fixture property explicitly names its stable
author identity; opaque source handles remain internal to SourceBuilder."
  (let* ((identity (plist-get props :source-identity))
         (arguments
          (list :key (plist-get props :key)
                :id (plist-get props :id)
                :class (plist-get props :class)
                :selector-state (plist-get props :selector-state)
                :selector-attributes (plist-get props :selector-attributes)
                :declarations declarations
                :provenance '(:adapter ebox-test))))
    (apply #'ebox-source-builder-bind
           builder
           (append
            (and identity (list :identity identity))
            arguments))))

(defun ebox-test--declarations (tag props)
  "Return canonical TAG declarations from evaluated fixture PROPS."
  (ebox-style-compile-form
   tag (ebox-test--without props ebox-test--non-style-fields)))

(defun ebox-test--layout (tag props declarations)
  "Return TAG LayoutConfig from PROPS and DECLARATIONS."
  (ebox-layout-config-for-form
   tag
   (if (memq tag '(row column))
       (ebox-test--keep props '(:item-gap :cross-align))
     (ebox-style-declaration-properties
      declarations
      (lambda (property)
        (memq (plist-get property :name)
              (ebox-layout-config-property-names tag)))))))

(defun ebox-test-text (value &rest props)
  "Return one canonical Text input for VALUE and author PROPS."
  (let* ((builder (ebox-source-builder-create))
         (declarations (ebox-test--declarations 'text props))
         (node
          (ebox-text-create
           :value value
           :owned-facts
           (ebox-canonical-facts-from-declarations 'text declarations)
           :source-handle
           (ebox-test--source-handle builder props declarations)))
         (index (ebox-source-builder-finish builder)))
    (ebox-canonical-input-create (list node) index)))

(defun ebox-test--normalize-child (builder child)
  "Import fixture CHILD into BUILDER and return its canonical node value."
  (cond
   ((ebox-canonical-input-p child)
    (ebox-source-builder-import builder (ebox-test-source-index child))
    (ebox-test-root child))
   ((ebox-child-range--descriptor-p child)
    (ebox-child-range--descriptor-create
     (ebox-child-range--descriptor-ref child)
     (mapcar (lambda (item)
               (ebox-test--normalize-child builder item))
             (ebox-child-range--descriptor-items child))))
   (t
    (error "Fixture child must be a canonical input or Range: %S" child))))

(defun ebox-test--box-node (tag props children)
  "Return canonical Box input TAG from PROPS and CHILDREN."
  (let* ((builder (ebox-source-builder-create))
         (declarations (ebox-test--declarations tag props))
         (nodes (mapcar (lambda (child)
                          (ebox-test--normalize-child builder child))
                        children))
         (node
          (let ((ebox-canonical--source-builder builder))
            (ebox-box-create
             :layout (ebox-test--layout tag props declarations)
             :outer (or (plist-get props :outer) 'block)
             :children nodes
             :owned-facts
             (ebox-canonical-facts-from-declarations tag declarations)
             :source-handle
             (ebox-test--source-handle builder props declarations))))
         (index (ebox-source-builder-finish builder)))
    (dolist (key ebox-test--direct-fields)
      (when (plist-member props key)
        (plist-put node key (copy-tree (plist-get props key)))))
    (ebox-canonical-input-create (list node) index)))

(defun ebox-test-box (&rest items)
  "Return one typed Normal Box fixture from evaluated ITEMS."
  (pcase-let ((`(,props . ,children) (ebox-test--split-items items)))
    (ebox-test--box-node 'box props children)))

(defun ebox-test-row (&rest items)
  "Return one typed Row fixture from evaluated ITEMS."
  (pcase-let ((`(,props . ,children) (ebox-test--split-items items)))
    (ebox-test--box-node 'row props (delq nil children))))

(defun ebox-test-column (&rest items)
  "Return one typed Column fixture from evaluated ITEMS."
  (pcase-let ((`(,props . ,children) (ebox-test--split-items items)))
    (ebox-test--box-node 'column props (delq nil children))))

(defun ebox-test-flex (&rest items)
  "Return one typed Flex fixture from evaluated ITEMS."
  (pcase-let ((`(,props . ,children) (ebox-test--split-items items)))
    (ebox-test--box-node 'flex props (delq nil children))))

(defun ebox-test-grid (&rest items)
  "Return one typed Grid fixture from evaluated ITEMS."
  (pcase-let ((`(,props . ,children) (ebox-test--split-items items)))
    (ebox-test--box-node 'grid props (delq nil children))))

(defun ebox-test-grid-fr (factor)
  "Return one fractional Grid track fixture."
  (list 'fr factor))

(defun ebox-test-flex-item (node &rest props)
  "Return INPUT with direct Flex participation and Box properties from PROPS."
  (unless (ebox-canonical-input-p node)
    (signal 'wrong-type-argument (list 'ebox-canonical-input-p node)))
  (unless (ebox-box-node-p (ebox-test-root node))
    (setq node (ebox-test--box-node 'box nil (list node))))
  (let* ((source-index (ebox-test-source-index node))
         (node (ebox-test-root node))
         (source (or (ebox-node-source-handle node)
                     (error "Fixture Box lacks an opaque source handle: %S"
                            node)))
         (layout (ebox-box-node-layout node))
         (children (ebox-box-node-children node))
         (base (ebox-style-node-declarations source-index node))
         (extra (ebox-test--declarations 'box props))
         (declarations (ebox-style-merge-declarations base extra))
         (binding
          (ebox-source-index-rebind
           source-index source :declarations declarations))
         (copy
          (ebox-box-create
           :layout layout
           :children children
           :outer (ebox-tree-display-outer node)
           :owned-facts
           (ebox-canonical-facts-from-declarations
            'box declarations)
           :source-handle (cdr binding))))
    (ebox-canonical-input-create (list copy) (car binding))))

(provide 'ebox-fixtures)

;;; ebox-fixtures.el ends here