;;; lang/go/config.el -*- lexical-binding: t; -*-

(def-package! go-mode
  :mode "\\.go$"
  :interpreter "go"
  :config
  (add-hook 'go-mode-hook #'flycheck-mode)

  (setq gofmt-command "goimports")
  (if (not (executable-find "goimports"))
      (warn "go-mode: couldn't find goimports; no code formatting/fixed imports on save")
    (add-hook! go-mode (add-hook 'before-save-hook #'gofmt-before-save nil t)))

  (set! :repl 'go-mode #'gorepl-run)
  (set! :jump 'go-mode
    :definition #'go-guru-definition
    :references #'go-guru-referrers
    :documentation #'godoc-at-point)

  (def-menu! +go/refactor-menu
    "Refactoring commands for `go-mode' buffers."
    '(("Add import"            :exec go-import-add            :region nil)
      ("Remove unused imports" :exec go-remove-unused-imports :region nil)
      ("Format buffer (gofmt)" :exec go-gofmt))
    :prompt "Refactor: ")

  (def-menu! +go/build-menu
    "Build/compilation commands for `go-mode' buffers."
    '(("Build project" :exec "go build")
      ("Build & run project" :exec "go run")
      ("Clean files" :exec "go clean"))
    :prompt "Run test: ")

  (def-menu! +go/test-menu
    "Test commands for `go-mode' buffers."
    '(("Last test"   :exec +go/test-rerun)
      ("All tests"   :exec +go/test-all)
      ("Single test" :exec +go/test-single)
      ("Nested test" :exec +go/test-nested))
    :prompt "Run test: ")

  (def-menu! +go/help-menu
    "Help and information commands for `go-mode' buffers."
    '(("Go to imports" :exec go-goto-imports)
      ("Lookup in godoc" :exec godoc-at-point)
      ("Describe this" :exec go-guru-describe)
      ("List free variables" :exec go-guru-freevars)
      ("What does this point to" :exec go-guru-pointsto)
      ("Implements relations for package types" :exec go-guru-implements :region nil)
      ("List peers for channel" :exec go-guru-peers)
      ("List references to object" :exec go-guru-referrers)
      ("Which errors" :exec go-guru-whicerrs)
      ("What query" :exec go-guru-what)
      ("Show callers of this function" :exec go-guru-callers :region nil)
      ("Show callees of this function" :exec go-guru-callees :region nil)))

  (map! :map go-mode-map
        :localleader
        "r" #'+go/refactor-menu
        "b" #'+go/build-menu
        "h" #'+go/help-menu
        "t" #'+go/test-menu
        :n "gr" #'go-play-buffer
        :v "gr" #'go-play-region))


(def-package! go-eldoc
  :hook (go-mode . go-eldoc-setup))


(def-package! go-guru
  :commands (go-guru-describe go-guru-freevars go-guru-implements go-guru-peers
             go-guru-referrers go-guru-definition go-guru-pointsto
             go-guru-callstack go-guru-whicherrs go-guru-callers go-guru-callees
             go-guru-expand-region)
  :config
  (unless (executable-find "guru")
    (warn "go-mode: couldn't find guru, refactoring commands won't work")))


(def-package! gorepl-mode
  :commands (gorepl-run gorepl-run-load-current-file)
  :config
  (unless (executable-find "gore")
    (warn "go-mode: couldn't find gore, REPL support disabled")))


(def-package! company-go
  :init (setq command-go-gocode-command "gocode")
  :when (featurep! :completion company)
  :after go-mode
  :config
  (if (executable-find command-go-gocode-command)
      (set! :company-backend 'go-mode '(company-go))
    (warn "go-mode: couldn't find gocode, code completion won't work")))