1	import Base
2	import ./fmt/out.bend as O
3	
4	# The command line of `cswap rpc [--format json|toon|yaml]` and
5	# `cswap serve --socket PATH [--format json|toon|yaml]`. Pure.
6	
7	type Plan is Data:
8	  PRpc{fmt: O.Fmt}
9	  PServe{path: String, fmt: O.Fmt}
10	  PBad{msg: String}
11	
12	type A is Data:
13	  A{fmt: Maybe<&2, String>, socket: Maybe<&2, String>, err: String, want: String}
14	
15	def err(+a: A, msg: String) -> A:
16	  match a:
17	    case A{fmt, socket, e, w}:
18	      A{fmt, socket, Bool.pick(String, String.is_empty(e), msg, e), ""}
19	
20	def got(+a: A, +v: String) -> A:
21	  match a:
22	    case A{fmt, socket, e, w}:
23	      Bool.pick(A, String.eq(w, "--format"), A{Some{v}, socket, e, ""}, A{fmt, Some{v}, e, ""})
24	
25	def want(+a: A, +flag: String) -> A:
26	  match a:
27	    case A{fmt, socket, e, w}:
28	      A{fmt, socket, e, flag}
29	
30	def pending(+a: A) -> Bool:
31	  match a:
32	    case A{fmt, socket, e, w}:
33	      Bool.not(String.is_empty(w))
34	
35	def sel.a(c: Bool, +x: A, +y: A) -> A:
36	  match c:
37	    case True{}:
38	      x
39	    case False{}:
40	      y
41	
42	def free(+h: String, +a: A) -> A:
43	  sel.a(String.eq(h, "--format") || String.eq(h, "--socket"), want(a, h),
44	  sel.a(String.starts_with(h, "--format="), got(want(a, "--format"), String.drop(h, 9n)),
45	  sel.a(String.starts_with(h, "--socket="), got(want(a, "--socket"), String.drop(h, 9n)),
46	  err(a, "unrecognized arguments: " ++ h))))
47	
48	def step(+h: String, +a: A) -> A:
49	  sel.a(pending(a), got(a, h), free(h, a))
50	
51	def go(args: List<&2, String>, +a: A) -> A:
52	  match args:
53	    case Nil{}:
54	      a
55	    case Con{h, t}:
56	      go(t, step(h, a))
57	
58	def end(+a: A) -> A:
59	  match a:
60	    case A{fmt, socket, e, w}:
61	      Bool.pick(A, String.is_empty(w), a, err(a, "argument " ++ w ++ ": expected one argument"))
62	
63	def fmt_of2(m: Maybe<&2, O.Fmt>, +name: String) -> Result<&2, &2, String, O.Fmt>:
64	  match m:
65	    case Some{O.FText{}}:
66	      Fail{"argument --format: invalid choice: '" ++ name ++ "' (choose from 'json', 'toon', 'yaml')"}
67	    case Some{O.FCsv{}}:
68	      Fail{"argument --format: invalid choice: '" ++ name ++ "' (choose from 'json', 'toon', 'yaml')"}
69	    case Some{f}:
70	      Done{f}
71	    case None{}:
72	      Fail{"argument --format: invalid choice: '" ++ name ++ "' (choose from 'json', 'toon', 'yaml')"}
73	
74	def fmt_of(m: Maybe<&2, String>) -> Result<&2, &2, String, O.Fmt>:
75	  match m:
76	    case None{}:
77	      Done{O.FJson{}}
78	    case Some{+n}:
79	      fmt_of2(O.of_name(n), n)
80	
81	def plan4(serve: Bool, +f: O.Fmt, socket: Maybe<&2, String>) -> Plan:
82	  match serve socket:
83	    case True{} Some{p}:
84	      PServe{p, f}
85	    case True{} None{}:
86	      PBad{"the following arguments are required: --socket"}
87	    case False{} _:
88	      PRpc{f}
89	
90	def plan3(+verb: String, r: Result<&2, &2, String, O.Fmt>, socket: Maybe<&2, String>) -> Plan:
91	  match r:
92	    case Fail{m}:
93	      PBad{m}
94	    case Done{f}:
95	      plan4(String.eq(verb, "serve"), f, socket)
96	
97	def plan2(+verb: String, +a: A) -> Plan:
98	  match a:
99	    case A{fmt, socket, e, w}:
100	      Bool.pick(Plan, String.is_empty(e), plan3(verb, fmt_of(fmt), socket), PBad{e})
101	
102	# `verb` is rpc or serve; `args` the words after it.
103	def plan(+verb: String, args: List<&2, String>) -> Plan:
104	  plan2(verb, end(go(args, A{None{}, None{}, "", ""})))