gitbay/MRs/MRDetailViewModel.swift
198 lines · 7607 bytes
1import Foundation
2import Observation
3
4/// One merge request: `mr show`, the parsed diff, the review threads, and
5/// every write the review cycle needs. Writes reload — the server's state
6/// is the state.
7@Observable
8@MainActor
9final class MRDetailViewModel {
10
11 private(set) var state: LoadState<MRDetail> = .loading
12 private(set) var diff: UnifiedDiff?
13 private(set) var threads: [ReviewThread] = []
14 private(set) var revisions: [MRRevision] = []
15 /// A write failed; the server's sentence, shown until the next action.
16 private(set) var actionError: String?
17 private(set) var working = false
18
19 private let client: GitbayClient
20 let repoPath: String
21 let number: Int64
22
23 init(client: GitbayClient, repoPath: String, number: Int64) {
24 self.client = client
25 self.repoPath = repoPath
26 self.number = number
27 }
28
29 private var ref: [String] { [repoPath, String(number)] }
30
31 func load() async {
32 do {
33 let detail = try await client.read(["mr", "show"] + ref, as: MRDetail.self)
34 state = .loaded(detail)
35 } catch {
36 state = .from(error)
37 return
38 }
39 // The diff and threads are secondary: their failure leaves the
40 // header usable rather than sinking the screen.
41 async let diffText = try? client.readText(["mr", "diff"] + ref)
42 async let threadList = try? client.readList(["mr", "threads"] + ref, of: ReviewThread.self)
43 async let revisionList = try? client.readList(["mr", "revisions"] + ref, of: MRRevision.self)
44 diff = (await diffText).map(UnifiedDiff.parse)
45 threads = await threadList ?? []
46 revisions = await revisionList ?? []
47 }
48
49 var unresolvedCount: Int {
50 threads.count { !$0.isResolved }
51 }
52
53 // MARK: - Writes
54
55 enum Verdict: String, Sendable {
56 case approve = "--approve"
57 case requestChanges = "--request-changes"
58 }
59
60 func review(_ verdict: Verdict) async {
61 await perform(["mr", "review"] + ref + [verdict.rawValue])
62 }
63
64 /// Both fields are always sent; an empty body clears it. `format` is
65 /// appended only when given; omitting it lets the server default.
66 func edit(title: String, body: String, format: String? = nil) async {
67 var argv = ["mr", "edit"] + ref + ["--title", title, "--file", "-"]
68 if let format { argv.append(contentsOf: ["--format", format]) }
69 await perform(argv, stdin: body)
70 }
71
72 /// Open milestones for the picker; fetched on first use.
73 private(set) var availableMilestones: [Milestone]?
74
75 func loadMilestones() async {
76 guard availableMilestones == nil else { return }
77 availableMilestones = (try? await client.readList(
78 ["milestone", "list", repoPath, "--state", "open"], of: Milestone.self
79 )) ?? []
80 }
81
82 /// nil clears it; the command spells that "none".
83 func setMilestone(_ title: String?) async {
84 await perform(["mr", "milestone"] + ref + [title ?? "none"])
85 }
86
87 func comment(_ text: String, format: String? = nil) async {
88 // Long text travels in stdin, but the server only reads it when
89 // argv says so: --file - is required, not implied.
90 var argv = ["mr", "comment"] + ref + ["--file", "-"]
91 if let format { argv.append(contentsOf: ["--format", format]) }
92 await perform(argv, stdin: text)
93 }
94
95 func merge(strategy: String? = nil) async {
96 var argv = ["mr", "merge"] + ref
97 if let strategy { argv.append(contentsOf: ["--strategy", strategy]) }
98 await perform(argv)
99 }
100
101 /// `--by` records which merge request replaces this one; the server
102 /// refuses a closed, merged or self reference.
103 func close(inFavourOf successor: Int64? = nil) async {
104 var argv = ["mr", "close"] + ref
105 if let successor { argv.append(contentsOf: ["--by", String(successor)]) }
106 await perform(argv)
107 }
108
109 /// The repository's other open merge requests, for the close-in-
110 /// favour picker. Fetched on demand and cached like `loadBranches()`;
111 /// this merge request is dropped since it cannot supersede itself.
112 private(set) var openMergeRequests: [MergeRequest]?
113 private(set) var openMergeRequestsError: String?
114
115 func loadOpenMergeRequests() async {
116 guard openMergeRequests == nil else { return }
117 openMergeRequestsError = nil
118 do {
119 let rows = try await client.readList(
120 ["mr", "list", repoPath, "--state", "open"], of: MergeRequest.self)
121 openMergeRequests = rows.filter { $0.number != number }
122 } catch let error as GitbayError {
123 openMergeRequestsError = error.userFacingMessage
124 } catch {
125 openMergeRequestsError = GitbayError.transport(error).userFacingMessage
126 }
127 }
128
129 func setResolved(_ thread: ReviewThread, _ resolved: Bool) async {
130 await perform(["mr", resolved ? "resolve" : "unresolve"] + ref + [String(thread.id)])
131 }
132
133 func reply(to thread: ReviewThread, _ text: String) async {
134 await perform(
135 ["mr", "diff-comment"] + ref + ["--reply", String(thread.id), "--file", "-"],
136 stdin: text
137 )
138 }
139
140 func setDraft(_ draft: Bool) async {
141 await perform(["mr", draft ? "draft" : "ready"] + ref)
142 }
143
144 func retarget(to branch: String) async {
145 await perform(["mr", "retarget"] + ref + [branch])
146 }
147
148 func requestReview(from user: String) async {
149 await perform(["mr", "review", "request"] + ref + ["--add", user])
150 }
151
152 func removeReviewRequest(_ user: String) async {
153 await perform(["mr", "review", "request"] + ref + ["--remove", user])
154 }
155
156 /// Branches for the retarget picker, fetched on demand from `repo refs`.
157 /// `nil` means "not yet loaded" so the picker can tell that apart from
158 /// a repository that genuinely has no other branches; a failed fetch
159 /// leaves `branches` nil and sets `branchesError` instead of silently
160 /// showing an empty list.
161 private(set) var branches: [String]?
162 private(set) var branchesError: String?
163
164 /// Cached for the life of this view model, same as `loadMilestones()`:
165 /// branches can go stale after a push, but re-opening the retarget
166 /// picker should not re-fetch every time. A pull-to-refresh of the
167 /// whole screen doesn't clear this cache either — retarget is a
168 /// secondary action, not the primary content `load()` refreshes.
169 func loadBranches() async {
170 guard branches == nil else { return }
171 branchesError = nil
172 do {
173 let refs = try await client.read(["repo", "refs", repoPath], as: RepoRefs.self)
174 branches = refs.branches.map(\.name)
175 } catch let error as GitbayError {
176 branchesError = error.userFacingMessage
177 } catch {
178 branchesError = GitbayError.transport(error).userFacingMessage
179 }
180 }
181
182 private func perform(_ argv: [String], stdin: String? = nil) async {
183 working = true
184 actionError = nil
185 defer { working = false }
186 do {
187 try await client.run(argv, stdin: stdin)
188 await load()
189 } catch let error as GitbayError {
190 // A refusal explains the rule (approvals missing, threads
191 // unresolved, checks red). Surface it verbatim; never route
192 // around it.
193 actionError = error.userFacingMessage
194 } catch {
195 actionError = GitbayError.transport(error).userFacingMessage
196 }
197 }
198}