;;; hc-results.el --- Shows query results in a compilation mode -*- lexical-binding: t; -*-

;; Copyright (C) 2022  Free Software Foundation, Inc.
;; 
;; This file is part of hcel.
;; 
;; hcel is free software: you can redistribute it and/or modify it under
;; the terms of the GNU Affero General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; 
;; hcel is distributed in the hope that it will be useful, but WITHOUT
;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
;; or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General
;; Public License for more details.
;; 
;; You should have received a copy of the GNU Affero General Public
;; License along with hcel.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; hcel-results provides functions for hcel modes derived from
;; compilation-mode.

;;; Code:
(require 'hcel-source)
(require 'hcel-utils)
(eval-when-compile (require 'compile))

(defun hcel-results-next-error-no-open (n)
  (interactive "p")
  (hcel-results-next-error-internal n))

(defun hcel-results-previous-error-no-open (n)
  (interactive "p")
  (hcel-results-next-error-no-open (- n)))

(defun hcel-results-next-error-internal (n &optional reset)
  (interactive "p")
  (if reset
      (progn
        (goto-char (point-min))
        (hcel-results-next-error-internal 1 nil))
    (if (> n 0)
        (dotimes (_unused n)
          (condition-case nil
              (progn
                (goto-char (next-single-property-change (point) 'match-line))
                (unless (get-text-property (point) 'match-line)
                  (goto-char
                   (next-single-property-change (point) 'match-line))))
            (error (hcel-results-next-page))))
      (dotimes (_unused (- n))
        (condition-case nil
            (progn
              (goto-char (previous-single-property-change (point) 'match-line))
              (unless (get-text-property (point) 'match-line)
                (goto-char
                 (previous-single-property-change (point) 'match-line))))
          (error (hcel-results-previous-page)))))))

(defun hcel-results-next-error (n &optional reset)
  (interactive "p")
  (hcel-results-next-error-internal n reset)
  (hcel-results-open))

(defun hcel-results-open ()
  (interactive)
  ;; TODO: arrow not working
  (compilation-set-overlay-arrow (selected-window))
  (hcel-load-module-location-info (get-text-property (point) 'location-info)))

(defvar-local hcel-results-page-number nil)
(defvar-local hcel-results-max-page-number nil)

(defun hcel-results-next-page ()
  (interactive)
  (unless (derived-mode-p 'hcel-refs-mode 'hcel-ids-mode)
    (error "Not in hcel-refs or hcel-ids mode: %S" major-mode))
  (when (= hcel-results-page-number hcel-results-max-page-number)
    (error "Already on the last page"))
  (setq hcel-results-page-number (1+ hcel-results-page-number))
  (cond ((derived-mode-p 'hcel-refs-mode) (hcel-refs-update-references))
        ((derived-mode-p 'hcel-ids-mode) (hcel-ids-update))
        (t (error "wrong major mode: %S" major-mode)))
  (hcel-results-next-error-internal 1))

(defun hcel-results-previous-page ()
  (interactive)
  (unless (derived-mode-p 'hcel-refs-mode 'hcel-ids-mode)
    (error "Not in hcel-refs or hcel-ids mode: %S" major-mode))
  (when (= hcel-results-page-number 1)
    (error "Already on the first page."))
  (setq hcel-results-page-number (1- hcel-results-page-number))
  (cond ((derived-mode-p 'hcel-refs-mode) (hcel-refs-update-references))
        ((derived-mode-p 'hcel-ids-mode) (hcel-ids-update))
        (t (error "wrong major mode: %S" major-mode)))
  (goto-char (point-max))
  (hcel-results-next-error-internal -1))

;; hcel-refs-mode
(defcustom hcel-refs-per-page 50
  "hcel refs number of results per page."
  :group 'hcel-refs :type '(natnum))

(defvar-local hcel-refs-id nil
  "External ID of the identifier we are looking for refs in the current buffer")
(defvar-local hcel-refs-package-id nil)

(define-compilation-mode hcel-refs-mode "hcel-refs"
  "Major mode for showing references"
  (setq-local next-error-function #'hcel-results-next-error))

(define-key hcel-refs-mode-map (kbd "M-n")
  #'hcel-results-next-error-no-open)

(define-key hcel-refs-mode-map (kbd "M-p")
  #'hcel-results-previous-error-no-open)

(defun hcel-refs-update-references ()
  "Find references and update the current hcel-refs-mode buffer."
  (unless (derived-mode-p 'hcel-refs-mode)
    (error "Not in hcel-refs mode!"))
  (let ((inhibit-read-only t)
        (modules-refs
         (hcel-api-references
          hcel-refs-package-id hcel-refs-id
          (number-to-string hcel-results-page-number)
          (number-to-string hcel-refs-per-page))))
    (erase-buffer)
    (insert (format "References of %s in %s, Page %d of %d.\n"
                    (hcel-refs-format-id hcel-refs-id)
                    (hcel-format-package-id hcel-refs-package-id)
                    hcel-results-page-number hcel-results-max-page-number))
    (mapc
     (lambda (module-refs)
       (let ((module-path (alist-get 'name module-refs))
             (refs (alist-get 'references module-refs)))
         (insert "References in "
                 (hcel-format-package-id hcel-refs-package-id "-")
                 " " module-path ": \n")
         (mapc
          (lambda (ref)
            (insert
             "--\n"
             (propertize
              (hcel-unquote-html
               (alist-get 'sourceCodeHtml ref))
              'location-info (hcel-id-src-span-to-location-info
                              hcel-refs-package-id module-path
                              (alist-get 'idSrcSpan ref)))))
          refs)))
     modules-refs)
    (goto-char (point-min))
    (while (re-search-forward "<b>\\(.*?\\)</b>" nil t)
      (replace-match
       (propertize (match-string 1) 'font-lock-face 'match))
      (save-excursion
        (add-text-properties (progn (beginning-of-line) (point))
                             (progn (end-of-line) (point))
                             (list 'match-line t)))))
  (goto-char (point-min)))

(defun hcel-refs-reload ()
  (interactive)
  (hcel-refs-update-references))
(define-key hcel-refs-mode-map "g" #'hcel-refs-reload)

(define-key hcel-refs-mode-map "f" #'hcel-results-next-page)

(define-key hcel-refs-mode-map "b" #'hcel-results-previous-page)

(defun hcel-refs-buffer-name (id)
  (format "*hcel-refs %s*" (hcel-refs-format-id id)))

(defun hcel-refs-format-id (id)
  (let* ((tuple (split-string id "|")))
    (format "%s (%s %s)"
            (cadddr tuple) (car tuple) (cadr tuple))))

(defun hcel-refs-update-references-package ()
  "Find references and update the current hcel-refs buffer.

Start by choosing a package."
  (interactive)
  (unless (derived-mode-p 'hcel-refs-mode)
    (error "Not in hcel-refs mode!"))
  (let* ((global-refs (hcel-api-global-references hcel-refs-id))
         (name (cadddr (split-string hcel-refs-id "|")))
         (package-id-and-count
          (split-string
           (completing-read
            (format "References of %s from: " name)
            (mapcar (lambda (pkg-count)
                      (format "%s (%s)"
                              (alist-get 'packageId pkg-count)
                              (alist-get 'count pkg-count)))
                    global-refs)
            nil t)))
         (package-id (car package-id-and-count))
         (count (string-to-number (substring (cadr package-id-and-count) 1 -1)))
         (max-page-number (1+ (/ count hcel-refs-per-page))))
    (setq hcel-refs-package-id (hcel-parse-package-id package-id "-")
          hcel-results-page-number 1
          hcel-results-max-page-number max-page-number)
    (hcel-refs-update-references)))
(define-key hcel-refs-mode-map "P" #'hcel-refs-update-references-package)

(defun hcel-find-references-at-point ()
  "Find references of the identifier at point."
  (interactive)
  (hcel-find-references-internal hcel-package-id hcel-module-path
                                 (hcel-text-property-near-point 'internal-id)))
(define-key hcel-mode-map (kbd "M-?") #'hcel-find-references-at-point)

(defun hcel-find-references-internal (package-id module-path internal-id)
  (when (and package-id module-path internal-id)
    (let ((hcel-buffer (hcel-buffer-name package-id module-path)))
      (when (or (get-buffer hcel-buffer)
                (and (y-or-n-p "Open module source?")
                     (hcel-load-module-source
                      package-id module-path))))
      (with-current-buffer hcel-buffer
        (when-let* ((external-id
                     (alist-get
                      'externalId
                      (alist-get (intern internal-id) hcel-identifiers)))
                    (buffer-name (hcel-refs-format-id external-id)))
          (with-current-buffer (get-buffer-create buffer-name)
            (hcel-refs-mode)
            (setq hcel-refs-id external-id)
            (hcel-refs-update-references-package))
          (switch-to-buffer-other-window buffer-name))))))
;; hcel-ids-mode
(defcustom hcel-ids-per-page 20
  "hcel-ids mode number of results per page."
  :group 'hcel-ids :type '(natnum))
(defcustom hcel-ids-live-per-page 10
  "hcel-ids live search results per page."
  :group 'hcel-ids :type '(natnum))

(defvar-local hcel-ids-scope nil)
(defvar-local hcel-ids-query nil)
(defvar-local hcel-ids-package-id nil)

(define-compilation-mode hcel-ids-mode "hcel-ids"
  "Major mode for showing identifiers"
  (setq-local next-error-function #'hcel-results-next-error))

(defun hcel-ids-update ()
  (unless (derived-mode-p 'hcel-ids-mode)
    (error "Not in hcel-ids mode!"))
  (when (and (eq hcel-ids-scope 'package) (not hcel-ids-package-id))
    (error "No package-id supplied for identifiers call!"))
  (let* ((inhibit-read-only t)
         (results
          (hcel-api-identifiers
           hcel-ids-scope hcel-ids-query hcel-ids-package-id
           (number-to-string hcel-results-page-number)
           (number-to-string hcel-ids-per-page)
           t)))
    (erase-buffer)
    (setq hcel-results-max-page-number
          (1+ (/ (string-to-number
                  (alist-get 'X-Total-Count
                             (alist-get 'header results)))
                 hcel-ids-per-page)))
    (insert (format "Results of %s, Page %d of %d.\n"
                    hcel-ids-query hcel-results-page-number
                    hcel-results-max-page-number))
    (mapc
     (lambda (identifier)
       (insert "--\n")
       (insert (hcel-ids-render-identifier
                identifier
                'hcel-tag-span-button-load-source)))
     (alist-get 'json results))
    (goto-char (point-min))))

(defun hcel-ids-render-identifier (identifier button-action)
  (let* ((location-info (alist-get 'locationInfo identifier))
         (doc (hcel-render-html
               (or (alist-get 'doc identifier)
                   (alist-get 'documentation
                              (ignore-errors
                                (hcel-definition-site-location-info
                                 location-info))))
               button-action)))
    (concat
     (propertize
      (format "%s :: %s\n"
              (alist-get 'occName identifier)
              (hcel-render-id-type (alist-get 'idType identifier)))
      'location-info location-info
      'match-line t)
     (concat "Defined in "
             (button-buttonize
              (format "%s %s"
                      (hcel-format-package-id
                       (alist-get 'packageId location-info) "-")
                      (alist-get 'modulePath location-info))
              (lambda (&rest _) (hcel-load-module-location-info location-info)))
             "\n")
     (when doc (concat "\n" doc)))))

(defun hcel-ids-reload ()
  (interactive)
  (hcel-ids-update))
(define-key hcel-ids-mode-map "g" #'hcel-ids-reload)

(define-key hcel-ids-mode-map (kbd "M-n")
  #'hcel-results-next-error-no-open)
(define-key hcel-ids-mode-map (kbd "M-p")
  #'hcel-results-previous-error-no-open)
(define-key hcel-ids-mode-map "f" #'hcel-results-next-page)
(define-key hcel-ids-mode-map "b" #'hcel-results-previous-page)

(defun hcel-ids-update-query (query)
  "Search for identities matching query."
  (interactive (list (progn
                       (unless (derived-mode-p 'hcel-ids-mode)
                         (error "Not in hcel-ids mode!"))
                       (read-string "Query: " hcel-ids-query))))
  (setq hcel-ids-query query
        hcel-results-page-number 1)
  (hcel-ids-update))
(define-key hcel-ids-mode-map "s" #'hcel-ids-update-query)

(defun hcel-ids-buffer-name (scope query)
  (format "*hcel-ids-%S %s*" scope query))

;; Caching results to prevent to many hits
(defvar hcel-ids--minibuffer-saved-query nil)
(defvar hcel-ids--minibuffer-saved-results nil)
(defvar hcel-ids--minibuffer-selected nil)
(defvar hcel-ids-minibuffer-component-max-len 80)

(defun hcel-ids--affixation-internal (scope items)
  (let ((results
         (mapcar
          (lambda (item)
            (let* ((identifier (get-text-property 0 'identifier item))
                   (location-info (alist-get 'locationInfo identifier))
                   (suffix
                    (propertize 
                     (format
                      " :: %s"
                      (hcel-render-components
                       (alist-get 'components (alist-get 'idType identifier))
                       nil
                       hcel-ids-minibuffer-component-max-len))
                     'face 'completions-annotations))
                   (prefix
                    (propertize
                     (if (eq scope 'global)
                         (format "(%s %s) "
                                 (alist-get 'moduleName location-info)
                                 (hcel-format-package-id
                                  (alist-get 'packageId location-info) "-"))
                       (format "(%s) "
                               (alist-get 'moduleName location-info)))
                     'face 'completions-annotations)))
              (list (car (split-string item " ")) prefix suffix)))
          items)))
    (setq hcel-ids--minibuffer-selected (car (car results)))
    results))

(defun hcel-ids--affixation-function (scope)
  (lambda (items)
    (hcel-ids--affixation-internal scope items)))

(defun hcel-ids-minibuffer-collection (scope query action &optional package-id)
  (when (and (eq scope 'package) (not package-id))
    (error "No package-id supplied for identifiers call!"))
  (if (eq action 'metadata)
      (list 'metadata (cons 'affixation-function
                            (hcel-ids--affixation-function scope)))
    (unless (length= query 0)
      (if (string= hcel-ids--minibuffer-saved-query query)
          hcel-ids--minibuffer-saved-results
        (setq hcel-ids--minibuffer-saved-query query
              hcel-ids--minibuffer-saved-results
              (mapcar
               (lambda (identifier)
                 (propertize
                  (format "%s %s"
                          (alist-get 'demangledOccName identifier)
                          (alist-get 'externalId identifier))
                  'identifier identifier))
               (hcel-api-identifiers
                scope query package-id nil
                (number-to-string hcel-ids-live-per-page))))
        hcel-ids--minibuffer-saved-results))))

(defun hcel-global-ids-minibuffer-collection (query _ action)
  (hcel-ids-minibuffer-collection 'global query action))

(defun hcel-package-ids-minibuffer-collection (package-id)
  (lambda (query _ action)
    (hcel-ids-minibuffer-collection 'package query action package-id)))

(defun hcel-ids (scope query &optional package-id)
  ;; FIXME: hacky way to detecting completion.
  (let ((splitted (split-string query " ")))
    (if (length= splitted 2)
        (hcel-load-module-location-info
         (alist-get 'locationInfo
                    (get-text-property 0 'identifier
                                       hcel-ids--minibuffer-selected)))
      (let ((buffer-name (hcel-ids-buffer-name scope query)))
        (with-current-buffer (get-buffer-create buffer-name)
          (hcel-ids-mode)
          (setq hcel-ids-scope scope
                hcel-ids-package-id package-id)
          (hcel-ids-update-query (car splitted)))
        (switch-to-buffer buffer-name)))))

(defun hcel-global-ids (query)
  (interactive (list
                (let ((minibuffer-allow-text-properties t))
                  (completing-read "Search for identifier globally: "
                                   #'hcel-global-ids-minibuffer-collection))))
  (hcel-ids 'global query))
(define-key hcel-mode-map "I" #'hcel-global-ids)

(defun hcel-package-ids (query)
  (interactive (list
                (let ((minibuffer-allow-text-properties t)
                      (package-id hcel-package-id))
                  (unless (derived-mode-p 'hcel-mode)
                    (error "Not in hcel-mode!"))
                  (completing-read
                   (format "Search for identifier in %s: "
                           (hcel-format-package-id package-id "-"))
                   (hcel-package-ids-minibuffer-collection package-id)))))
  (hcel-ids 'package query hcel-package-id))
(define-key hcel-mode-map "i" #'hcel-package-ids)

(defun hcel-tag-span-button-help (marker)
  (hcel-help-internal
   (hcel-global-identifier
    (get-text-property marker 'location-info)
    (hcel-string-with-text-property-at-point 'location-info))))

(defun hcel-help-internal (identifier)
  (help-setup-xref (list #'hcel-help-internal identifier)
                   (called-interactively-p 'interactive))
  (with-help-window (help-buffer)
    (with-current-buffer standard-output
      (insert
       (hcel-ids-render-identifier
        identifier 'hcel-tag-span-button-help)))))

(defun hcel-help (query)
  (interactive
   (list
    (let ((minibuffer-allow-text-properties t))
      (completing-read "Find help for identifier: "
                       #'hcel-global-ids-minibuffer-collection))))
  (when (length= (split-string query " ") 2)
    (hcel-help-internal
     (get-text-property 0 'identifier hcel-ids--minibuffer-selected))))

(provide 'hcel-results)
;;; hcel-results.el ends here.