1	# ledger/render: a ledger written back out as ez.toml, and the two edits the
2	# command line makes to it. Rendering is from the model, so the file it writes
3	# is the file it would read back.
4	import Base
5	import ./manifest.bend as M
6	import ../toml/toml.bend as T
7	
8	# a key line, or nothing at all when the value is empty, so an absent tag,
9	# entry or bin leaves no trace
10	def line(key: String, +val: String) -> String:
11	  Bool.pick(String, String.is_empty(val), "", key ++ " = \"" ++ val ++ "\"\n")
12	
13	# a key line whose value is written bare, as a TOML boolean is, or nothing at
14	# all when the value is empty
15	def line.bare(key: String, +val: String) -> String:
16	  Bool.pick(String, String.is_empty(val), "", key ++ " = " ++ val ++ "\n")
17	
18	# `true` when the tree is committed, and nothing when it is not, so the key
19	# is absent rather than written as an empty string. It is written bare: in
20	# TOML `vendor = "true"` is a string, and a reader other than ez, such as
21	# nix's `builtins.fromTOML`, would take it for one. ez reads both spellings.
22	def vendor.word(vend: Bool) -> String:
23	  match vend:
24	    case True{}:
25	      "true"
26	    case False{}:
27	      ""
28	
29	# the keys a source contributes
30	def source(src: M.Source) -> String:
31	  match src:
32	    case M.Hub{named}:
33	      line("hub", named)
34	    case M.Git{url, rev, tag, root, nar, vend}:
35	      line("git", url) ++ line("rev", rev) ++ line("tag", tag) ++
36	      line("root", root) ++ line("narHash", nar) ++ line.bare("vendor", vendor.word(vend))
37	    case M.Member{path, named}:
38	      line.bare("workspace", "true") ++ line("path", path) ++ line("hub", named)
39	
40	# one `[deps.<name>]` section
41	def dep(dependency: M.Dep) -> String:
42	  M.Dep{n, h, e, s} = dependency
43	  "\n[deps." ++ n ++ "]\n" ++ line("hash", h) ++ source(s) ++ line("entry", e)
44	
45	# every dependency, in the order the ledger holds them
46	def deps(ds: List<&2, M.Dep>) -> String:
47	  match ds:
48	    case []:
49	      ""
50	    case h <> t:
51	      dep(h) ++ deps(t)
52	
53	# one `[tools.<name>]` section. No hash: a tool is not a package.
54	def tool(pin: M.Tool) -> String:
55	  M.Tool{n, e, b, s} = pin
56	  "\n[tools." ++ n ++ "]\n" ++ source(s) ++ line("entry", e) ++ line("bin", b)
57	
58	# every pinned CLI, in the order the ledger holds them
59	def tools(ts: List<&2, M.Tool>) -> String:
60	  match ts:
61	    case []:
62	      ""
63	    case h <> t:
64	      tool(h) ++ tools(t)
65	
66	# the ledger as ez assembles it, in the TOML ez wrote before eztoml 0.4
67	def text(manifest: M.Manifest) -> String:
68	  M.Manifest{n, e, b, h, pa, pv, ds, ts} = manifest
69	  "[package]\n" ++ line("name", n) ++ line("entry", e) ++ line("bin", b) ++
70	    line("hub", h) ++ line("publish-as", pa) ++ line("version", pv) ++
71	    deps(ds) ++ tools(ts)
72	
73	# the ledger as an ez.toml: ez's text, written as eztoml writes it
74	def show(manifest: M.Manifest) -> String:
75	  T.normal(text(manifest))
76	
77	# a ledger that was read, as an ez.toml; an unreadable one renders as nothing,
78	# so a failed read can never overwrite a good file with a guess
79	def render(ledger: M.Read) -> String:
80	  match ledger:
81	    case M.Bad{_why}:
82	      ""
83	    case M.Good{m}:
84	      show(m)
85	
86	# a dependency kept or dropped
87	def without.put(hit: Bool, dependency: M.Dep, rest: List<&2, M.Dep>) -> List<&2, M.Dep>:
88	  match hit:
89	    case True{}:
90	      rest
91	    case False{}:
92	      dependency <> rest
93	
94	# every dependency but the one named
95	def without(ds: List<&2, M.Dep>, +name: String) -> List<&2, M.Dep>:
96	  match ds:
97	    case []:
98	      []
99	    case +h <> t:
100	      without.put(String.eq(M.dep.name(h), name), h, without(t, name))
101	
102	# the ledger with a dependency added, replacing any of the same name, so adding
103	# twice is the same as adding once
104	def add(manifest: M.Manifest, +dependency: M.Dep) -> M.Manifest:
105	  M.Manifest{n, e, b, h, pa, pv, ds, ts} = manifest
106	  M.Manifest{n, e, b, h, pa, pv, List.append(&2, M.Dep, without(ds, M.dep.name(dependency)), [dependency]), ts}
107	
108	# the ledger with a dependency dropped
109	def remove(manifest: M.Manifest, name: String) -> M.Manifest:
110	  M.Manifest{n, e, b, h, pa, pv, ds, ts} = manifest
111	  M.Manifest{n, e, b, h, pa, pv, without(ds, name), ts}
112	
113	# a git source with its tree committed
114	def vendored(src: M.Source) -> M.Source:
115	  match src:
116	    case M.Hub{named}:
117	      M.Hub{named}
118	    case M.Git{url, rev, tag, root, nar, _vend}:
119	      M.Git{url, rev, tag, root, nar, True{}}
120	    case M.Member{path, named}:
121	      M.Member{path, named}
122	
123	# a source that keeps a vendor bit the ledger already set, or is left as given
124	def revend(keep: Bool, src: M.Source) -> M.Source:
125	  match keep:
126	    case True{}:
127	      vendored(src)
128	    case False{}:
129	      src
130	
131	# a dependency added again keeps the `vendor = true` its entry already had.
132	# The command line has no way to say it, so a re-add that dropped it would
133	# drop the tree from the allowlist without anyone having asked.
134	def readd(ds: List<&2, M.Dep>, dependency: M.Dep) -> M.Dep:
135	  M.Dep{+n, h, e, s} = dependency
136	  M.Dep{n, h, e, revend(M.source.vendor(M.source.dep(M.find(ds, n))), s)}
137	
138	# the ledger with a dependency added, keeping the vendor bit of the entry it
139	# replaces
140	def add.keep(manifest: M.Manifest, dependency: M.Dep) -> M.Manifest:
141	  M.Manifest{n, e, b, h, pa, pv, +ds, ts} = manifest
142	  add(M.Manifest{n, e, b, h, pa, pv, ds, ts}, readd(ds, dependency))
143	
144	# ---------------------------------------------------------------------------
145	# what a ledger may hold to be written
146	
147	# whether a text holds no copy of a char
148	def clear(text: String, +ch: Char) -> Bool:
149	  match text:
150	    case SNil{}:
151	      True{}
152	    case SCon{h, t}:
153	      rest = clear(t, ch)
154	      Bool.and(Bool.not(Char.is_eq(h, ch)), rest)
155	
156	# whether a name or value can be written as it is: it holds no `"`, no `\`
157	# and no newline. The pinned eztoml reader (v0.1.0) neither writes nor reads
158	# escapes, a newline would end the line, and a quote or a backslash would make
159	# the file mean something else to every other TOML reader, nix's among them.
160	def clean(+text: String) -> Bool:
161	  Bool.and(clear(text, '"'), Bool.and(clear(text, '\\'), clear(text, '\n')))
162	
163	# whether a source reads back as itself. A git source names its repo and the
164	# directory its paths are written from: the reader takes a section with no
165	# `git` for a hub package and one with no `root` for the top of the checkout.
166	# A workspace member's is `workspace = true`, with the directory and the name
167	# only the joint ledger gives it.
168	def source.ok(src: M.Source) -> Bool:
169	  match src:
170	    case M.Hub{+named}:
171	      clean(named)
172	    case M.Git{+url, rev, tag, +root, nar, _vend}:
173	      Bool.and(Bool.and(Bool.not(String.is_empty(url)), Bool.not(String.is_empty(root))),
174	        Bool.and(Bool.and(clean(url), clean(rev)),
175	          Bool.and(clean(tag), Bool.and(clean(root), clean(nar)))))
176	    case M.Member{+path, +named}:
177	      Bool.and(clean(path), clean(named))
178	
179	# whether a dependency's hash can be written: one is there, which the reader
180	# asks every dependency for but a workspace member's, whose ledger records
181	# none and whose hash only the joint ledger gives
182	def hash.ok(src: M.Source, +hash: String) -> Bool:
183	  match src:
184	    case M.Hub{_named}:
185	      Bool.and(Bool.not(String.is_empty(hash)), clean(hash))
186	    case M.Git{_url, _rev, _tag, _root, _nar, _vend}:
187	      Bool.and(Bool.not(String.is_empty(hash)), clean(hash))
188	    case M.Member{_path, _named}:
189	      clean(hash)
190	
191	# whether a dependency does: it has a hash, but for a workspace member, and
192	# every name and value is clean
193	def dep.ok(dependency: M.Dep) -> Bool:
194	  M.Dep{+n, +h, +e, +s} = dependency
195	  Bool.and(Bool.and(clean(n), hash.ok(s, h)),
196	    Bool.and(clean(e), source.ok(s)))
197	
198	# whether every dependency does
199	def deps.ok(ds: List<&2, M.Dep>) -> Bool:
200	  match ds:
201	    case []:
202	      True{}
203	    case h <> t:
204	      rest = deps.ok(t)
205	      Bool.and(dep.ok(h), rest)
206	
207	# whether a pinned CLI's source does. A tool is never imported, so the reader
208	# keeps no hub name for one, and one written with a name would read back
209	# without it.
210	def tool.src.ok(src: M.Source) -> Bool:
211	  match src:
212	    case M.Hub{named}:
213	      String.is_empty(named)
214	    case M.Git{url, rev, tag, root, nar, vend}:
215	      source.ok(M.Git{url, rev, tag, root, nar, vend})
216	    case M.Member{_path, _named}:
217	      False{}
218	
219	# whether a pinned CLI does
220	def tool.ok(pin: M.Tool) -> Bool:
221	  M.Tool{+n, +e, +b, s} = pin
222	  Bool.and(clean(n), Bool.and(Bool.and(clean(e), clean(b)), tool.src.ok(s)))
223	
224	# whether every pinned CLI does
225	def tools.ok(ts: List<&2, M.Tool>) -> Bool:
226	  match ts:
227	    case []:
228	      True{}
229	    case h <> t:
230	      rest = tools.ok(t)
231	      Bool.and(tool.ok(h), rest)
232	
233	# whether a ledger can be written so that it reads back as itself (EZ-LED-4):
234	# every name and value is clean, `publish-as` and `version` among them, every
235	# dependency has a hash, and every git source names its repo and its root.
236	# Every command that writes ez.toml refuses a ledger that is not, so every
237	# ledger ez writes is one of these.
238	def renderable(manifest: M.Manifest) -> Bool:
239	  M.Manifest{+n, +e, +b, +h, +pa, +pv, ds, ts} = manifest
240	  Bool.and(Bool.and(Bool.and(clean(n), clean(e)), Bool.and(clean(b), clean(h))),
241	    Bool.and(Bool.and(clean(pa), clean(pv)), Bool.and(deps.ok(ds), tools.ok(ts))))
242	
243	# why a ledger that is not renderable is not written
244	def unrenderable() -> String:
245	  "ez: ez.toml cannot be written: a name or value holds a quote, a backslash or a newline, a dependency has no hash, or a git source names no repo or no root"