;; Go tokenizer tests.

(define go-test-count 0)
(define go-test-pass 0)
(define go-test-fails (list))

(define gtok-type (fn (t) (get t :type)))
(define gtok-value (fn (t) (get t :value)))
(define tok-types (fn (src) (map gtok-type (go-tokenize src))))
(define tok-values (fn (src) (map gtok-value (go-tokenize src))))

(define
  go-test
  (fn
    (name actual expected)
    (set! go-test-count (+ go-test-count 1))
    (if
      (= actual expected)
      (set! go-test-pass (+ go-test-pass 1))
      (append! go-test-fails {:name name :expected expected :actual actual}))))

;; ── empty / whitespace ────────────────────────────────────────────
(go-test "empty source" (tok-types "") (list "eof"))
(go-test "spaces only" (tok-types "   ") (list "eof"))
(go-test "tabs only" (tok-types "\t\t") (list "eof"))
(go-test
  "newline only — no prior token, no ASI"
  (tok-types "\n")
  (list "eof"))

;; ── identifiers ───────────────────────────────────────────────────
(go-test "ident: simple" (tok-values "foo") (list "foo" "\n" nil))
(go-test
  "ident: underscore prefix"
  (tok-values "_bar")
  (list "_bar" "\n" nil))
(go-test "ident: mixed case" (tok-values "fooBar") (list "fooBar" "\n" nil))
(go-test "ident: with digits" (tok-values "x123") (list "x123" "\n" nil))
(go-test "ident: type tag" (tok-types "foo") (list "ident" "semi" "eof"))

;; ── keywords (all 25) ─────────────────────────────────────────────
(go-test "kw: break" (tok-types "break") (list "keyword" "semi" "eof"))
(go-test "kw: case" (tok-types "case") (list "keyword" "eof"))
(go-test "kw: chan" (tok-types "chan") (list "keyword" "eof"))
(go-test "kw: const" (tok-types "const") (list "keyword" "eof"))
(go-test "kw: continue" (tok-types "continue") (list "keyword" "semi" "eof"))
(go-test "kw: default" (tok-types "default") (list "keyword" "eof"))
(go-test "kw: defer" (tok-types "defer") (list "keyword" "eof"))
(go-test "kw: else" (tok-types "else") (list "keyword" "eof"))
(go-test
  "kw: fallthrough"
  (tok-types "fallthrough")
  (list "keyword" "semi" "eof"))
(go-test "kw: for" (tok-types "for") (list "keyword" "eof"))
(go-test "kw: func" (tok-types "func") (list "keyword" "eof"))
(go-test "kw: go" (tok-types "go") (list "keyword" "eof"))
(go-test "kw: goto" (tok-types "goto") (list "keyword" "eof"))
(go-test "kw: if" (tok-types "if") (list "keyword" "eof"))
(go-test "kw: import" (tok-types "import") (list "keyword" "eof"))
(go-test "kw: interface" (tok-types "interface") (list "keyword" "eof"))
(go-test "kw: map" (tok-types "map") (list "keyword" "eof"))
(go-test "kw: package" (tok-types "package") (list "keyword" "eof"))
(go-test "kw: range" (tok-types "range") (list "keyword" "eof"))
(go-test "kw: return" (tok-types "return") (list "keyword" "semi" "eof"))
(go-test "kw: select" (tok-types "select") (list "keyword" "eof"))
(go-test "kw: struct" (tok-types "struct") (list "keyword" "eof"))
(go-test "kw: switch" (tok-types "switch") (list "keyword" "eof"))
(go-test "kw: type" (tok-types "type") (list "keyword" "eof"))
(go-test "kw: var" (tok-types "var") (list "keyword" "eof"))

;; ── integer literals — decimal ────────────────────────────────────
(go-test "int: zero" (tok-values "0") (list "0" "\n" nil))
(go-test "int: small" (tok-values "42") (list "42" "\n" nil))
(go-test "int: bigger" (tok-values "123456") (list "123456" "\n" nil))
(go-test "int: type" (tok-types "42") (list "int" "semi" "eof"))

;; ── integer literals — prefixed + underscores ─────────────────────
(go-test "int: hex lower" (tok-values "0x1f") (list "0x1f" "\n" nil))
(go-test "int: hex upper-x" (tok-values "0X1F") (list "0X1F" "\n" nil))
(go-test
  "int: hex mixed digits"
  (tok-values "0xDEADbeef")
  (list "0xDEADbeef" "\n" nil))
(go-test "int: binary lower" (tok-values "0b1010") (list "0b1010" "\n" nil))
(go-test "int: binary upper" (tok-values "0B1101") (list "0B1101" "\n" nil))
(go-test "int: octal modern" (tok-values "0o755") (list "0o755" "\n" nil))
(go-test "int: octal upper" (tok-values "0O17") (list "0O17" "\n" nil))
(go-test "int: octal legacy" (tok-values "0755") (list "0755" "\n" nil))
(go-test "int: hex type" (tok-types "0x1F") (list "int" "semi" "eof"))
(go-test "int: bin type" (tok-types "0b101") (list "int" "semi" "eof"))
(go-test
  "int: dec underscore"
  (tok-values "1_000_000")
  (list "1_000_000" "\n" nil))
(go-test
  "int: hex underscore"
  (tok-values "0xDEAD_BEEF")
  (list "0xDEAD_BEEF" "\n" nil))
(go-test
  "int: bin underscore"
  (tok-values "0b1010_1010")
  (list "0b1010_1010" "\n" nil))
(go-test
  "int: hex then +"
  (tok-types "0xFF + 1")
  (list "int" "op" "int" "semi" "eof"))

;; ── float literals (Go spec § Floating-point literals) ────────────
(go-test "float: simple" (tok-values "3.14") (list "3.14" "\n" nil))
(go-test "float: trailing dot" (tok-values "1.") (list "1." "\n" nil))
(go-test "float: leading dot" (tok-values ".5") (list ".5" "\n" nil))
(go-test "float: exp lower" (tok-values "1e10") (list "1e10" "\n" nil))
(go-test "float: exp upper" (tok-values "1E5") (list "1E5" "\n" nil))
(go-test "float: exp negative" (tok-values "1.5e-3") (list "1.5e-3" "\n" nil))
(go-test "float: exp positive" (tok-values "2.0e+2") (list "2.0e+2" "\n" nil))
(go-test "float: zero" (tok-values "0.0") (list "0.0" "\n" nil))
(go-test "float: dot-only-exp" (tok-values ".5e2") (list ".5e2" "\n" nil))
(go-test "float: underscore" (tok-values "1_000.5") (list "1_000.5" "\n" nil))
(go-test "float: type" (tok-types "3.14") (list "float" "semi" "eof"))
(go-test
  "float: trailing dot type"
  (tok-types "1.")
  (list "float" "semi" "eof"))
(go-test
  "float: exp-only type"
  (tok-types "1e10")
  (list "float" "semi" "eof"))
(go-test
  "float: then +"
  (tok-types "3.14 + 0.1")
  (list "float" "op" "float" "semi" "eof"))
(go-test
  "float: greedy 1.method"
  (tok-types "1.method")
  (list "float" "ident" "semi" "eof"))

;; ── imaginary literals (Go spec § Imaginary literals) ─────────────
(go-test "imag: int i" (tok-values "2i") (list "2i" "\n" nil))
(go-test "imag: float i" (tok-values "3.14i") (list "3.14i" "\n" nil))
(go-test "imag: exp i" (tok-values "1e2i") (list "1e2i" "\n" nil))
(go-test "imag: int-i type" (tok-types "2i") (list "imag" "semi" "eof"))
(go-test "imag: float-i type" (tok-types "3.14i") (list "imag" "semi" "eof"))
(go-test "imag: ASI at newline" (tok-types "1i\n") (list "imag" "semi" "eof"))

;; ── string literals ───────────────────────────────────────────────
(go-test "raw: simple" (tok-values "`hello`") (list "hello" "\n" nil))
(go-test "raw: empty" (tok-values "``") (list "" "\n" nil))
(go-test
  "raw: backslash literal — no escape processing"
  (tok-values "`a\\nb`")
  (list "a\\nb" "\n" nil))
(go-test
  "raw: multi-line"
  (tok-values "`line1\nline2`")
  (list "line1\nline2" "\n" nil))
(go-test
  "raw: contains double-quote"
  (tok-values "`say \"hi\"`")
  (list "say \"hi\"" "\n" nil))
(go-test
  "raw: CR stripped (Go spec § String literals)"
  (tok-values "`a\r\nb`")
  (list "a\nb" "\n" nil))
(go-test "raw: type" (tok-types "`x`") (list "string" "semi" "eof"))

;; ── rune literals ─────────────────────────────────────────────────
(go-test
  "raw: then +"
  (tok-types "`x` + 1")
  (list "string" "op" "int" "semi" "eof"))
(go-test
  "raw: ASI at newline after"
  (tok-types "`abc`\n")
  (list "string" "semi" "eof"))
(go-test "string: empty" (tok-values "\"\"") (list "" "\n" nil))

;; ── comments ──────────────────────────────────────────────────────
(go-test "string: hello" (tok-values "\"hello\"") (list "hello" "\n" nil))
(go-test
  "string: with space"
  (tok-values "\"hi there\"")
  (list "hi there" "\n" nil))
(go-test "string: escape n" (tok-values "\"a\\nb\"") (list "a\nb" "\n" nil))
(go-test "string: escape quote" (tok-values "\"a\\\"b\"") (list "a\"b" "\n" nil))
(go-test
  "string: escape backslash"
  (tok-values "\"a\\\\b\"")
  (list "a\\b" "\n" nil))

;; ── operators & punctuation ───────────────────────────────────────
(go-test "string: type" (tok-types "\"x\"") (list "string" "semi" "eof"))
(go-test "rune: simple" (tok-values "'a'") (list "a" "\n" nil))
(go-test "rune: escape" (tok-values "'\\n'") (list "\n" "\n" nil))
(go-test "rune: type" (tok-types "'a'") (list "rune" "semi" "eof"))
(go-test "line comment" (tok-types "// ignored") (list "eof"))
(go-test "line comment then code" (tok-values "// hi\nx") (list "x" "\n" nil))
(go-test "block comment" (tok-types "/* a b c */") (list "eof"))
(go-test
  "block comment inline"
  (tok-values "x /* mid */ y")
  (list "x" "y" "\n" nil))
(go-test
  "block comment with newline — ASI"
  (tok-types "x /* multi\nline */ y")
  (list "ident" "semi" "ident" "semi" "eof"))

;; ── automatic semicolon insertion (Go spec § Semicolons) ──────────
(go-test
  "ops: arithmetic"
  (tok-values "+ - * / %")
  (list "+" "-" "*" "/" "%" nil))
(go-test
  "ops: comparison"
  (tok-values "== != < > <= >=")
  (list "==" "!=" "<" ">" "<=" ">=" nil))
(go-test "ops: logical" (tok-values "&& || !") (list "&&" "||" "!" nil))
(go-test
  "ops: assign forms"
  (tok-values "= := += -=")
  (list "=" ":=" "+=" "-=" nil))
(go-test "ops: channel arrow" (tok-values "<- chan") (list "<-" "chan" nil))
(go-test "ops: incdec ASI" (tok-types "++ --") (list "op" "op" "semi" "eof"))
(go-test "ops: ellipsis" (tok-values "...") (list "..." nil))
(go-test
  "punct: all brackets"
  (tok-values "( ) { } [ ]")
  (list "(" ")" "{" "}" "[" "]" "\n" nil))
(go-test
  "punct: comma colon dot"
  (tok-values ", : .")
  (list "," ":" "." nil))
(go-test
  "ASI: after ident at newline"
  (tok-types "x\ny")
  (list "ident" "semi" "ident" "semi" "eof"))
(go-test "ASI: after int" (tok-types "42\n") (list "int" "semi" "eof"))
(go-test "ASI: after float" (tok-types "3.14\n") (list "float" "semi" "eof"))
(go-test
  "ASI: after string"
  (tok-types "\"hi\"\n")
  (list "string" "semi" "eof"))
(go-test "ASI: after rune" (tok-types "'a'\n") (list "rune" "semi" "eof"))

;; ── short program ─────────────────────────────────────────────────
(go-test
  "ASI: after )"
  (tok-types "f()\n")
  (list "ident" "op" "op" "semi" "eof"))
(go-test
  "ASI: after ]"
  (tok-types "x[0]\n")
  (list "ident" "op" "int" "op" "semi" "eof"))
(go-test "ASI: after }" (tok-types "{}\n") (list "op" "op" "semi" "eof"))

;; ── report ────────────────────────────────────────────────────────
(go-test "ASI: after ++" (tok-types "i++\n") (list "ident" "op" "semi" "eof"))

(go-test
  "ASI: NOT after +"
  (tok-types "x +\ny")
  (list "ident" "op" "ident" "semi" "eof"))

(go-test
  "ASI: NOT after ("
  (tok-types "f(\nx)")
  (list "ident" "op" "ident" "op" "semi" "eof"))

(go-test
  "ASI: blank lines collapse — single semi only"
  (tok-types "x\n\n\ny")
  (list "ident" "semi" "ident" "semi" "eof"))

(go-test
  "ASI: at EOF after ident"
  (tok-types "x")
  (list "ident" "semi" "eof"))

(go-test
  "ASI: explicit semi"
  (tok-types "x;y")
  (list "ident" "semi" "ident" "semi" "eof"))

(go-test
  "short-decl: x := 42 (types)"
  (tok-types "x := 42")
  (list "ident" "op" "int" "semi" "eof"))

(go-test
  "short-decl: x := 42 (values)"
  (tok-values "x := 42")
  (list "x" ":=" "42" "\n" nil))

(go-test
  "func decl shape"
  (tok-types "func foo() int { return 0 }")
  (list
    "keyword"
    "ident"
    "op"
    "op"
    "ident"
    "op"
    "keyword"
    "int"
    "op"
    "semi"
    "eof"))

(define go-lex-test-summary (str "lex " go-test-pass "/" go-test-count))