#!/usr/bin/env janet

# need to get comment, link, doctag, string literal/regexp, other literal, keyword  identifier?
# based on https://github.com/php/php-langspec/blob/ca697b43031efd70b5306d29b74e1190e7eacac8/spec/19-grammar.md

(defn read-from-file [file-path]
  "Read a file from string filepath"
  (let [f (file/open file-path :r)
        content  (file/read f :all)]
    (file/close f)
    content))

(defn write-to-file [file-path content]
  "Append to file from string filepath"
  (let [f (file/open file-path :w)]
    (file/write f content)
    (file/flush f)
    (file/close f)
    content))


(defn pp-ast
  "Pretty prints the PHP AST (as provided by (peg/match php-to-ast))"
  [ast]
  (if ast
    (do
      (print "[")
      (map |(printf "\t%q" $0) ast)
      (print "]"))))

(defn htmlspecialchars
  "Convert html special chars from a string"
  [value]
    (string/replace-all "\"" """
      (string/replace-all "'" "'"
        (string/replace-all "<" "&lt;" 
          (string/replace-all ">" "&gt;"
            (string/replace-all "&" "&amp;" value))))))

(def php-to-ast
  "A custom markdown flavored grammar"
    ~{
        :end-of-line (* (? "\r") "\n")
        
        :single-line-comment (cmt (<- (* (+ "//" "#") (some (if-not :end-of-line 1)))),|[:single-line-comment (string/join $&)])
        :multi-line-comment (cmt (<- (* "/*" (some (if-not "*/" 1)) "*/")),|[:multi-line-comment (string/join $&)])
        :comment (+ :single-line-comment :multi-line-comment)

        :string (cmt (<- (* "\""  (some (if-not "\"" 1)) "\"")),|[:string (string/join $&)])

        :name-non-digit (+ :a "_")
        :name (some (+ :name-non-digit (range "\x80\xFF")))
        :variable (cmt (<- (* "$" :name)),|[:variable (string/join $&)])

        :scalar-type (+ "bool" "float" "int" "string")
        :base-type (+ "array" "callable" "iterable" :scalar-type)
        :return-type (cmt (<- (+ :base-type "void")),|[:return-type $0])

        :keyword (cmt (<- (+  "abstract" "and" "array" "as" "break" "callable" "case" "catch" "class" "clone"
                    "const" "continue" "declare" "default" "die" "do" "echo" "else" "elseif" "empty"
                    "enddeclare" "endfor" "endforeach" "endif" "endswitch" "endwhile" "eval" "exit"
                    "extends" "final" "finally" "for" "foreach" "function" "fn" "global"
                    "goto" "if" "implements" "include" "include_once" "instanceof"
                    "insteadof" "interface" "isset" "list" "namespace" "new" "or" "print" "private"
                    "protected" "public" "require" "require_once" "return" "static" "switch"
                    "throw" "trait" "try" "unset" "use" "var" "while" "xor" "yield" "yield from")),|[:keyword $0])

        :other (cmt (<- (if-not :comment 1)),|[:other (string/join $&)])

        :main (some (+ :comment :string :variable :return-type :keyword :other))})

(defn ast-to-html
  [ast]
    (string/join
      (map
        |(match $0
            [:single-line-comment value] (string "<span style=\"color:#a0a1a7;font-style:italic\">" (htmlspecialchars value) "</span>")
            [:multi-line-comment value] (string "<span style=\"color:#a0a1a7;font-style:italic\">" (htmlspecialchars value) "</span>")
            [:string value] (string "<span style=\"color:#50a14f\">" (htmlspecialchars value) "</span>")
            [:variable value] (string "<span style=\"color:#986801\">" (htmlspecialchars value) "</span>")
            [:return-type value] (string "<span style=\"color:#216ce7\">" (htmlspecialchars value) "</span>")
            [:keyword value] (string "<span style=\"color:#a626a4\">" (htmlspecialchars value) "</span>")
            [:other value] (htmlspecialchars value)
            _ (error (string "Invalid symbol: " (get $0 0))))
          ast)
        ""))


(defn main [bin & args]
    # (pp-ast (peg/match php-to-ast (read-from-file "sample.php"))))
    (write-to-file "php.html" (string "<pre><code>" (ast-to-html (peg/match php-to-ast (read-from-file "sample.php"))) "</code></pre>")))