;; ==========================================================================
;; test-parser.sx — Tests for the SX parser and serializer
;;
;; Requires: test-framework.sx loaded first.
;; Modules tested: parser.sx
;;
;; Platform functions required (beyond test framework):
;;   sx-parse       (source)  -> list of AST expressions
;;   sx-serialize   (expr)    -> SX source string
;;   make-symbol    (name)    -> Symbol value
;;   make-keyword   (name)    -> Keyword value
;;   symbol-name    (sym)     -> string
;;   keyword-name   (kw)      -> string
;; ==========================================================================


;; --------------------------------------------------------------------------
;; Literal parsing
;; --------------------------------------------------------------------------

(defsuite "parser-literals"
  (deftest "parse integers"
    (assert-equal (list 42) (sx-parse "42"))
    (assert-equal (list 0) (sx-parse "0"))
    (assert-equal (list -7) (sx-parse "-7")))

  (deftest "parse floats"
    (assert-equal (list 3.14) (sx-parse "3.14"))
    (assert-equal (list -0.5) (sx-parse "-0.5")))

  (deftest "parse strings"
    (assert-equal (list "hello") (sx-parse "\"hello\""))
    (assert-equal (list "") (sx-parse "\"\"")))

  (deftest "parse escape: newline"
    (assert-equal (list "a\nb") (sx-parse "\"a\\nb\"")))

  (deftest "parse escape: tab"
    (assert-equal (list "a\tb") (sx-parse "\"a\\tb\"")))

  (deftest "parse escape: quote"
    (assert-equal (list "a\"b") (sx-parse "\"a\\\"b\"")))

  (deftest "parse booleans"
    (assert-equal (list true) (sx-parse "true"))
    (assert-equal (list false) (sx-parse "false")))

  (deftest "parse nil"
    (assert-equal (list nil) (sx-parse "nil")))

  (deftest "parse keywords"
    (let ((result (sx-parse ":hello")))
      (assert-length 1 result)
      (assert-equal "hello" (keyword-name (first result)))))

  (deftest "parse symbols"
    (let ((result (sx-parse "foo")))
      (assert-length 1 result)
      (assert-equal "foo" (symbol-name (first result))))))


;; --------------------------------------------------------------------------
;; Composite parsing
;; --------------------------------------------------------------------------

(defsuite "parser-lists"
  (deftest "parse empty list"
    (let ((result (sx-parse "()")))
      (assert-length 1 result)
      (assert-equal (list) (first result))))

  (deftest "parse list of numbers"
    (let ((result (sx-parse "(1 2 3)")))
      (assert-length 1 result)
      (assert-equal (list 1 2 3) (first result))))

  (deftest "parse nested lists"
    (let ((result (sx-parse "(1 (2 3) 4)")))
      (assert-length 1 result)
      (assert-equal (list 1 (list 2 3) 4) (first result))))

  (deftest "parse sibling sublists"
    ;; Regression: closing paren of (b) must not swallow (c) as a child
    (let ((result (sx-parse "(a (b) (c))")))
      (assert-length 1 result)
      (assert-length 3 (first result))
      (assert-equal (list (make-symbol "a") (list (make-symbol "b")) (list (make-symbol "c")))
                    (first result))))

  (deftest "parse multiple sibling sublists with content"
    (let ((result (sx-parse "(div (span 1) (span 2) (span 3))")))
      (assert-length 1 result)
      (assert-length 4 (first result))))

  (deftest "parse square brackets as list"
    (let ((result (sx-parse "[1 2 3]")))
      (assert-length 1 result)
      (assert-equal (list 1 2 3) (first result))))

  (deftest "parse mixed types"
    (let ((result (sx-parse "(42 \"hello\" true nil)")))
      (assert-length 1 result)
      (let ((lst (first result)))
        (assert-equal 42 (nth lst 0))
        (assert-equal "hello" (nth lst 1))
        (assert-equal true (nth lst 2))
        (assert-nil (nth lst 3))))))


;; --------------------------------------------------------------------------
;; Dict parsing
;; --------------------------------------------------------------------------

(defsuite "parser-dicts"
  (deftest "parse empty dict"
    (let ((result (sx-parse "{}")))
      (assert-length 1 result)
      (assert-type "dict" (first result))))

  (deftest "parse dict with keyword keys"
    (let ((result (sx-parse "{:a 1 :b 2}")))
      (assert-length 1 result)
      (let ((d (first result)))
        (assert-type "dict" d)
        (assert-equal 1 (get d "a"))
        (assert-equal 2 (get d "b")))))

  (deftest "parse dict with string values"
    (let ((result (sx-parse "{:name \"alice\"}")))
      (assert-length 1 result)
      (assert-equal "alice" (get (first result) "name")))))


;; --------------------------------------------------------------------------
;; Comments and whitespace
;; --------------------------------------------------------------------------

(defsuite "parser-whitespace"
  (deftest "skip line comments"
    (assert-equal (list 42) (sx-parse ";; comment\n42"))
    (assert-equal (list 1 2) (sx-parse "1 ;; middle\n2")))

  (deftest "skip whitespace"
    (assert-equal (list 42) (sx-parse "  42  "))
    (assert-equal (list 1 2) (sx-parse " 1 \n\t 2 ")))

  (deftest "parse multiple top-level expressions"
    (assert-length 3 (sx-parse "1 2 3"))
    (assert-equal (list 1 2 3) (sx-parse "1 2 3")))

  (deftest "empty input"
    (assert-equal (list) (sx-parse "")))

  (deftest "only comments"
    (assert-equal (list) (sx-parse ";; just a comment\n;; another"))))


;; --------------------------------------------------------------------------
;; Quote sugar
;; --------------------------------------------------------------------------

(defsuite "parser-quote-sugar"
  (deftest "quasiquote"
    (let ((result (sx-parse "`foo")))
      (assert-length 1 result)
      (let ((expr (first result)))
        (assert-type "list" expr)
        (assert-equal "quasiquote" (symbol-name (first expr))))))

  (deftest "unquote"
    (let ((result (sx-parse ",foo")))
      (assert-length 1 result)
      (let ((expr (first result)))
        (assert-type "list" expr)
        (assert-equal "unquote" (symbol-name (first expr))))))

  (deftest "splice-unquote"
    (let ((result (sx-parse ",@foo")))
      (assert-length 1 result)
      (let ((expr (first result)))
        (assert-type "list" expr)
        (assert-equal "splice-unquote" (symbol-name (first expr)))))))


;; --------------------------------------------------------------------------
;; Serializer
;; --------------------------------------------------------------------------

(defsuite "serializer"
  (deftest "serialize number"
    (assert-equal "42" (sx-serialize 42)))

  (deftest "serialize string"
    (assert-equal "\"hello\"" (sx-serialize "hello")))

  (deftest "serialize boolean"
    (assert-equal "true" (sx-serialize true))
    (assert-equal "false" (sx-serialize false)))

  (deftest "serialize nil"
    (assert-equal "nil" (sx-serialize nil)))

  (deftest "serialize keyword"
    (assert-equal ":foo" (sx-serialize (make-keyword "foo"))))

  (deftest "serialize symbol"
    (assert-equal "bar" (sx-serialize (make-symbol "bar"))))

  (deftest "serialize list"
    (assert-equal "(1 2 3)" (sx-serialize (list 1 2 3))))

  (deftest "serialize empty list"
    (assert-equal "()" (sx-serialize (list))))

  (deftest "serialize nested"
    (assert-equal "(1 (2 3) 4)" (sx-serialize (list 1 (list 2 3) 4)))))


;; --------------------------------------------------------------------------
;; Round-trip: parse then serialize
;; --------------------------------------------------------------------------

(defsuite "parser-roundtrip"
  (deftest "roundtrip number"
    (assert-equal "42" (sx-serialize (first (sx-parse "42")))))

  (deftest "roundtrip string"
    (assert-equal "\"hello\"" (sx-serialize (first (sx-parse "\"hello\"")))))

  (deftest "roundtrip list"
    (assert-equal "(1 2 3)" (sx-serialize (first (sx-parse "(1 2 3)")))))

  (deftest "roundtrip nested"
    (assert-equal "(a (b c))"
      (sx-serialize (first (sx-parse "(a (b c))"))))))


;; --------------------------------------------------------------------------
;; Reader macros
;; --------------------------------------------------------------------------

(defsuite "reader-macros"
  (deftest "datum comment discards expr"
    (assert-equal (list 42) (sx-parse "#;(ignored) 42")))

  (deftest "datum comment in list"
    (assert-equal (list (list 1 3)) (sx-parse "(1 #;2 3)")))

  (deftest "datum comment discards nested"
    (assert-equal (list 99) (sx-parse "#;(a (b c) d) 99")))

  (deftest "raw string basic"
    (assert-equal (list "hello") (sx-parse "#|hello|")))

  (deftest "raw string with quotes"
    (assert-equal (list "say \"hi\"") (sx-parse "#|say \"hi\"|")))

  (deftest "raw string with backslashes"
    (assert-equal (list "a\\nb") (sx-parse "#|a\\nb|")))

  (deftest "raw string empty"
    (assert-equal (list "") (sx-parse "#||")))

  (deftest "quote shorthand symbol"
    (let ((result (first (sx-parse "#'foo"))))
      (assert-equal "quote" (symbol-name (first result)))
      (assert-equal "foo" (symbol-name (nth result 1)))))

  (deftest "quote shorthand list"
    (let ((result (first (sx-parse "#'(1 2 3)"))))
      (assert-equal "quote" (symbol-name (first result)))
      (assert-equal (list 1 2 3) (nth result 1))))

  (deftest "apostrophe quote expands to (quote ...)"
    (let ((result (sx-parse "'x")))
      (assert-length 1 result)
      (let ((expr (first result)))
        (assert-type "list" expr)
        (assert-equal "quote" (symbol-name (first expr)))
        (assert-equal "x" (symbol-name (nth expr 1))))))

  (deftest "apostrophe quote on list"
    (let ((result (sx-parse "'(1 2 3)")))
      (assert-length 1 result)
      (let ((expr (first result)))
        (assert-type "list" expr)
        (assert-equal "quote" (symbol-name (first expr)))
        (assert-equal (list 1 2 3) (nth expr 1)))))

  (deftest "quasiquote with unquote inside"
    (let ((result (sx-parse "`(a ,b)")))
      (assert-length 1 result)
      (let ((expr (first result)))
        (assert-type "list" expr)
        (assert-equal "quasiquote" (symbol-name (first expr)))
        (let ((inner (nth expr 1)))
          (assert-type "list" inner)
          (assert-equal "a" (symbol-name (first inner)))
          (let ((unquoted (nth inner 1)))
            (assert-type "list" unquoted)
            (assert-equal "unquote" (symbol-name (first unquoted)))))))))


;; --------------------------------------------------------------------------
;; Number formats
;; --------------------------------------------------------------------------

(defsuite "parser-numbers"
  (deftest "integer zero"
    (assert-equal (list 0) (sx-parse "0")))

  (deftest "large integer"
    (assert-equal (list 1000000) (sx-parse "1000000")))

  (deftest "negative float"
    (assert-equal (list -2.718) (sx-parse "-2.718")))

  (deftest "exponent notation"
    (let ((result (sx-parse "1e10")))
      (assert-length 1 result)
      (assert-type "number" (first result))
      (assert-equal 10000000000 (first result))))

  (deftest "negative exponent"
    (let ((result (sx-parse "2.5e-1")))
      (assert-length 1 result)
      (assert-type "number" (first result))
      (assert-equal 0.25 (first result))))

  (deftest "uppercase exponent E"
    (let ((result (sx-parse "1E3")))
      (assert-length 1 result)
      (assert-type "number" (first result))
      (assert-equal 1000 (first result)))))


;; --------------------------------------------------------------------------
;; Symbol naming conventions
;; --------------------------------------------------------------------------

(defsuite "parser-symbols"
  (deftest "symbol with hyphens"
    (let ((result (sx-parse "my-var")))
      (assert-length 1 result)
      (assert-equal "my-var" (symbol-name (first result)))))

  (deftest "symbol with question mark"
    (let ((result (sx-parse "nil?")))
      (assert-length 1 result)
      (assert-equal "nil?" (symbol-name (first result)))))

  (deftest "symbol with exclamation"
    (let ((result (sx-parse "set!")))
      (assert-length 1 result)
      (assert-equal "set!" (symbol-name (first result)))))

  (deftest "symbol with tilde (component)"
    (let ((result (sx-parse "~my-comp")))
      (assert-length 1 result)
      (assert-equal "~my-comp" (symbol-name (first result)))))

  (deftest "symbol with arrow"
    (let ((result (sx-parse "->")))
      (assert-length 1 result)
      (assert-equal "->" (symbol-name (first result)))))

  (deftest "symbol with &"
    (let ((result (sx-parse "&key")))
      (assert-length 1 result)
      (assert-equal "&key" (symbol-name (first result)))))

  (deftest "symbol with every? style"
    (let ((result (sx-parse "every?")))
      (assert-length 1 result)
      (assert-equal "every?" (symbol-name (first result)))))

  (deftest "ellipsis is a symbol"
    (let ((result (sx-parse "...")))
      (assert-length 1 result)
      (assert-equal "..." (symbol-name (first result))))))


;; --------------------------------------------------------------------------
;; Serializer — extended
;; --------------------------------------------------------------------------

(defsuite "serializer-extended"
  (deftest "serialize negative number"
    (assert-equal "-5" (sx-serialize -5)))

  (deftest "serialize float"
    (assert-equal "3.14" (sx-serialize 3.14)))

  (deftest "serialize string with escaped quote"
    (let ((s (sx-serialize "say \"hi\"")))
      (assert-true (string-contains? s "\\\""))))

  (deftest "serialize dict round-trips"
    ;; Parse a dict literal, serialize it, parse again — values survive.
    (let ((d (first (sx-parse "{:x 1 :y 2}"))))
      (let ((s (sx-serialize d)))
        (assert-true (string-contains? s ":x"))
        (assert-true (string-contains? s ":y"))
        (let ((d2 (first (sx-parse s))))
          (assert-equal 1 (get d2 "x"))
          (assert-equal 2 (get d2 "y"))))))

  (deftest "serialize symbol with hyphens"
    (assert-equal "my-fn" (sx-serialize (make-symbol "my-fn"))))

  (deftest "serialize keyword with hyphens"
    (assert-equal ":my-key" (sx-serialize (make-keyword "my-key"))))

  (deftest "serialize deeply nested list"
    (assert-equal "(1 (2 (3)))"
      (sx-serialize (list 1 (list 2 (list 3)))))))


;; --------------------------------------------------------------------------
;; Round-trip — extended
;; --------------------------------------------------------------------------

(defsuite "parser-roundtrip-extended"
  (deftest "roundtrip keyword"
    (let ((parsed (first (sx-parse ":hello"))))
      (assert-equal ":hello" (sx-serialize parsed))))

  (deftest "roundtrip negative number"
    (assert-equal "-7" (sx-serialize (first (sx-parse "-7")))))

  (deftest "roundtrip float"
    (assert-equal "3.14" (sx-serialize (first (sx-parse "3.14")))))

  (deftest "roundtrip string with newline escape"
    (let ((parsed (first (sx-parse "\"a\\nb\""))))
      ;; Parsed value contains a real newline character.
      (assert-equal "a\nb" parsed)
      ;; Serialized form must escape it back.
      (let ((serialized (sx-serialize parsed)))
        (assert-true (string-contains? serialized "\\n")))))

  (deftest "roundtrip symbol with question mark"
    (let ((parsed (first (sx-parse "empty?"))))
      (assert-equal "empty?" (sx-serialize parsed))))

  (deftest "roundtrip component symbol"
    (let ((parsed (first (sx-parse "~card"))))
      (assert-equal "~card" (sx-serialize parsed))))

  (deftest "roundtrip keyword arguments in list"
    (let ((src "(~comp :title \"Hi\" :count 3)"))
      (assert-equal src
        (sx-serialize (first (sx-parse src))))))

  (deftest "roundtrip empty list"
    (assert-equal "()" (sx-serialize (first (sx-parse "()")))))

  (deftest "roundtrip mixed-type list"
    (let ((src "(1 \"hello\" true nil)"))
      (assert-equal src
        (sx-serialize (first (sx-parse src)))))))


;; --------------------------------------------------------------------------
;; Edge cases
;; --------------------------------------------------------------------------

(defsuite "parser-edge-cases"
  (deftest "empty string parses to empty list"
    (assert-equal (list) (sx-parse "")))

  (deftest "whitespace-only parses to empty list"
    (assert-equal (list) (sx-parse "   \n\t  ")))

  (deftest "multiple top-level expressions"
    (let ((result (sx-parse "1 2 3")))
      (assert-length 3 result)
      (assert-equal 1 (nth result 0))
      (assert-equal 2 (nth result 1))
      (assert-equal 3 (nth result 2))))

  (deftest "multiple top-level mixed types"
    (let ((result (sx-parse "42 \"hello\" true nil")))
      (assert-length 4 result)
      (assert-equal 42 (nth result 0))
      (assert-equal "hello" (nth result 1))
      (assert-equal true (nth result 2))
      (assert-nil (nth result 3))))

  (deftest "deeply nested list"
    ;; (((((1))))) — parser returns one top-level expression
    (let ((result (sx-parse "(((((1)))))")))
      (assert-length 1 result)))

  (deftest "long string value"
    (let ((long-str (join "" (map (fn (x) "abcdefghij") (range 0 10)))))
      (let ((src (str "\"" long-str "\"")))
        (assert-equal (list long-str) (sx-parse src)))))

  (deftest "inline comment inside list"
    (let ((result (sx-parse "(+ 1 ;; comment\n 2)")))
      (assert-length 1 result)
      (assert-equal (list (make-symbol "+") 1 2) (first result))))

  (deftest "comment at end of file with no trailing newline"
    (assert-equal (list 1) (sx-parse "1 ;; trailing comment")))

  (deftest "keyword with numeric suffix"
    (let ((result (sx-parse ":item-1")))
      (assert-length 1 result)
      (assert-equal "item-1" (keyword-name (first result)))))

  (deftest "consecutive keywords parsed as separate atoms"
    (let ((result (sx-parse ":a :b :c")))
      (assert-length 3 result)
      (assert-equal "a" (keyword-name (nth result 0)))
      (assert-equal "b" (keyword-name (nth result 1)))
      (assert-equal "c" (keyword-name (nth result 2)))))

  (deftest "symbol immediately after opening paren"
    (let ((result (first (sx-parse "(foo)"))))
      (assert-length 1 result)
      (assert-equal "foo" (symbol-name (first result)))))

  (deftest "parse boolean true is not a symbol"
    (let ((result (first (sx-parse "true"))))
      (assert-type "boolean" result)
      (assert-equal true result)))

  (deftest "parse boolean false is not a symbol"
    (let ((result (first (sx-parse "false"))))
      (assert-type "boolean" result)
      (assert-equal false result)))

  (deftest "parse nil is not a symbol"
    (let ((result (first (sx-parse "nil"))))
      (assert-nil result))))


;; --------------------------------------------------------------------------
;; JIT regression: mutable pos shared via upvalues across recursive calls
;; --------------------------------------------------------------------------

(defsuite "parser-jit-regression"
  (deftest "letrec parser with mutable pos — recursive sublists"
    ;; Minimal reproducer for the sx-parse JIT bug.
    ;; Uses define inside fn (like sx-parse's read-list-loop pattern).
    (let ((parse-fn (fn (src)
            (let ((pos 0))
              (letrec
                ((read-list (fn ()
                   (let ((result (list))
                         (done false))
                     (define go (fn ()
                       (when (and (not done) (< pos (len src)))
                         (let ((ch (nth src pos)))
                           (set! pos (inc pos))
                           (cond
                             (= ch ")") (set! done true)
                             (= ch "(") (do (append! result (read-list)) (go))
                             :else (do (append! result ch) (go)))))))
                     (go)
                     result))))
                (set! pos 1)
                (read-list))))))
      (let ((r (parse-fn "(a(b)(c))")))
        (assert (list? r) (str "result should be list, got type=" (type-of r)))
        (assert-equal 3 (len r))
        (assert-equal (list "a" (list "b") (list "c")) r))))
)

(defsuite "define-as-local"
  (deftest "define inside fn creates local, not global"
    ;; When define is inside a fn body, recursive calls must each
    ;; get their own copy. If define writes to global, recursive
    ;; calls overwrite each other.
    (let ((result
            (let ((counter 0))
              (letrec
                ((make-counter (fn ()
                   (define my-val counter)
                   (set! counter (inc counter))
                   my-val)))
                (list (make-counter) (make-counter) (make-counter))))))
      (assert-equal (list 0 1 2) result)))

  (deftest "define inside fn with self-recursion via define"
    ;; read-list-loop pattern: define a function that calls itself
    (let ((result
            (let ((items (list)))
              (define go (fn (n)
                (when (< n 3)
                  (append! items n)
                  (go (inc n)))))
              (go 0)
              items)))
      (assert-equal (list 0 1 2) result)))

  (deftest "recursive define inside letrec fn doesn't overwrite"
    ;; Each call to make-list creates its own 'loop' local
    (let ((make-list (fn (items)
            (let ((result (list)))
              (define loop (fn (i)
                (when (< i (len items))
                  (append! result (nth items i))
                  (loop (inc i)))))
              (loop 0)
              result))))
      (assert-equal (list "a" "b") (make-list (list "a" "b")))
      (assert-equal (list 1 2 3) (make-list (list 1 2 3))))))