; lib/gitea/tests/pr.sx — Phase 5: PR records, live merge-base diffs,
; review threads (latest verdict per reviewer), the durable flow
; lifecycle, all four merge shapes (merge/ff/up-to-date/conflicts), the
; merge queue, and the PR web routes + JSON API.

(st-bootstrap-classes!)
(content/bootstrap!)
(content-bootstrap-markdown!)
(content-bootstrap-table!)

(define gitea-pr-pass 0)
(define gitea-pr-fail 0)
(define gitea-pr-fails (list))

(define
  gitea-pr-test
  (fn
    (name actual expected)
    (if
      (= actual expected)
      (set! gitea-pr-pass (+ gitea-pr-pass 1))
      (begin
        (set! gitea-pr-fail (+ gitea-pr-fail 1))
        (set! gitea-pr-fails (append gitea-pr-fails (list {:name name :expected (inspect expected) :actual (inspect actual)})))))))

; ── setup: repo with diverged branches ───────────────────────────────

(define gp-db (persist/mem-backend))
(define gp-forge (gitea/forge gp-db))
(gitea/user-create! gp-forge "alice")
(gitea/user-create! gp-forge "bob")
(gitea/user-create! gp-forge "carol")
(gitea/user-create! gp-forge "eve")
(gitea/repo-create! gp-forge "alice" "proj" {})
(gitea/repo-create! gp-forge "alice" "sec" {:visibility "private"})
(gitea/token-create! gp-forge "alice" "tok-a")
(gitea/token-create! gp-forge "bob" "tok-b")
(gitea/token-create! gp-forge "carol" "tok-c")
(gitea/token-create! gp-forge "eve" "tok-e")

(define gp-g (gitea/repo-git gp-forge "alice" "proj"))
(git/add! gp-g "README.md" "base\n")
(git/add! gp-g "lib.txt" "lib\n")
(define gp-c1 (git/commit! gp-g {:message "c1" :time 1 :author "alice"}))
(git/branch! gp-g "feat")
(git/checkout! gp-g "feat")
(git/add! gp-g "feature.txt" "feature line\n")
(define gp-c2 (git/commit! gp-g {:message "c2 feature" :time 2 :author "bob"}))
(git/checkout! gp-g "main")
(git/add! gp-g "other.txt" "other\n")
(define gp-c3 (git/commit! gp-g {:message "c3 other" :time 3 :author "alice"}))

; ── create / validate ────────────────────────────────────────────────

(define
  gp-pr1
  (gitea/pr-create!
    gp-forge
    "alice"
    "proj"
    "bob"
    "Add feature"
    "feat"
    "main"
    "Adds a *feature*."
    {:created-at 5}))

(gitea-pr-test "pr number" (get gp-pr1 :number) 1)
(gitea-pr-test "pr state" (get gp-pr1 :state) "open")
(gitea-pr-test "pr source" (get gp-pr1 :source) "feat")
(gitea-pr-test "pr target" (get gp-pr1 :target) "main")
(gitea-pr-test "pr has flow id" (nil? (get gp-pr1 :flow-id)) false)
(gitea-pr-test
  "flow starts at review"
  (gitea/pr-flow-status gp-forge gp-pr1)
  "review")

(gitea-pr-test
  "unknown source"
  (get
    (gitea/pr-create!
      gp-forge
      "alice"
      "proj"
      "bob"
      "t"
      "nope"
      "main"
      ""
      {})
    :error)
  "no-such-source")
(gitea-pr-test
  "unknown target"
  (get
    (gitea/pr-create!
      gp-forge
      "alice"
      "proj"
      "bob"
      "t"
      "feat"
      "nope"
      ""
      {})
    :error)
  "no-such-target")
(gitea-pr-test
  "same branch"
  (get
    (gitea/pr-create!
      gp-forge
      "alice"
      "proj"
      "bob"
      "t"
      "main"
      "main"
      ""
      {})
    :error)
  "same-branch")
(gitea-pr-test
  "empty title"
  (get
    (gitea/pr-create!
      gp-forge
      "alice"
      "proj"
      "bob"
      ""
      "feat"
      "main"
      ""
      {})
    :error)
  "empty-title")
(gitea-pr-test
  "missing repo"
  (get
    (gitea/pr-create!
      gp-forge
      "alice"
      "none"
      "bob"
      "t"
      "feat"
      "main"
      ""
      {})
    :error)
  "no-such-repo")
(gitea-pr-test
  "missing author"
  (get
    (gitea/pr-create!
      gp-forge
      "alice"
      "proj"
      "zeb"
      "t"
      "feat"
      "main"
      ""
      {})
    :error)
  "no-such-user")

(gitea-pr-test
  "prs list"
  (gitea/prs gp-forge "alice" "proj")
  (list 1))

; numbers are shared with issues
(gitea-pr-test
  "shared counter with issues"
  (get
    (gitea/issue-create!
      gp-forge
      "alice"
      "proj"
      "alice"
      "An issue"
      ""
      {})
    :number)
  2)

; ── live diff against the merge base ─────────────────────────────────

(gitea-pr-test
  "diff added"
  (get (gitea/pr-diff gp-forge "alice" "proj" 1) :added)
  (list "feature.txt"))
(gitea-pr-test
  "diff no spurious deletions"
  (get (gitea/pr-diff gp-forge "alice" "proj" 1) :deleted)
  (list))
(gitea-pr-test
  "diff unified shows addition"
  (contains?
    (gitea/pr-diff-unified gp-forge "alice" "proj" 1)
    "+feature line")
  true)
(gitea-pr-test
  "diff of missing pr"
  (gitea/pr-diff gp-forge "alice" "proj" 99)
  nil)

; ── reviews ──────────────────────────────────────────────────────────

(gitea/pr-review!
  gp-forge
  "alice"
  "proj"
  1
  "carol"
  "request-changes"
  "needs tests"
  {:at 6})
(gitea-pr-test
  "changes requested blocks approval"
  (gitea/pr-approved? (gitea/pr-get gp-forge "alice" "proj" 1))
  false)
(gitea-pr-test
  "flow still at review"
  (gitea/pr-flow-status
    gp-forge
    (gitea/pr-get gp-forge "alice" "proj" 1))
  "review")

(gitea-pr-test
  "author cannot review own pr"
  (get
    (gitea/pr-review!
      gp-forge
      "alice"
      "proj"
      1
      "bob"
      "approve"
      ""
      {})
    :error)
  "own-pr")
(gitea-pr-test
  "invalid verdict"
  (get
    (gitea/pr-review!
      gp-forge
      "alice"
      "proj"
      1
      "carol"
      "meh"
      ""
      {})
    :error)
  "invalid-verdict")
(gitea-pr-test
  "unknown reviewer"
  (get
    (gitea/pr-review!
      gp-forge
      "alice"
      "proj"
      1
      "zeb"
      "approve"
      ""
      {})
    :error)
  "no-such-user")
(gitea-pr-test
  "review missing pr"
  (get
    (gitea/pr-review!
      gp-forge
      "alice"
      "proj"
      99
      "carol"
      "approve"
      ""
      {})
    :error)
  "no-such-pr")

(gitea/pr-review!
  gp-forge
  "alice"
  "proj"
  1
  "carol"
  "approve"
  "looks good now"
  {:at 7})
(gitea-pr-test
  "latest verdict wins"
  (gitea/pr-approved? (gitea/pr-get gp-forge "alice" "proj" 1))
  true)
(gitea-pr-test
  "reviews accumulate"
  (len (get (gitea/pr-get gp-forge "alice" "proj" 1) :reviews))
  2)
(gitea-pr-test
  "flow advanced to approved"
  (gitea/pr-flow-status
    gp-forge
    (gitea/pr-get gp-forge "alice" "proj" 1))
  "approved")

; ── merge: true 3-way ────────────────────────────────────────────────

(gitea-pr-test
  "unapproved merge rejected"
  (get
    (gitea/pr-merge! gp-forge "alice" "proj" 2 "alice" {})
    :error)
  "no-such-pr")

(define
  gp-m1
  (gitea/pr-merge! gp-forge "alice" "proj" 1 "alice" {:time 8}))

(gitea-pr-test "merge state" (get gp-m1 :state) "merged")
(gitea-pr-test "merge cid recorded" (nil? (get gp-m1 :merge-cid)) false)
(gitea-pr-test
  "main moved to merge commit"
  (git/branch-get gp-g "main")
  (get gp-m1 :merge-cid))
(gitea-pr-test
  "merge commit has two parents"
  (git/commit-parents (git/read gp-g (get gp-m1 :merge-cid)))
  (list gp-c3 gp-c2))
(gitea-pr-test
  "merged tree keeps target file"
  (get (gitea/tree-at gp-g (get gp-m1 :merge-cid) "other.txt") :kind)
  "blob")
(gitea-pr-test
  "merged tree gains source file"
  (get (gitea/tree-at gp-g (get gp-m1 :merge-cid) "feature.txt") :kind)
  "blob")
(gitea-pr-test
  "flow reports merged"
  (gitea/pr-flow-status
    gp-forge
    (gitea/pr-get gp-forge "alice" "proj" 1))
  "merged")
(gitea-pr-test
  "merge twice rejected"
  (get
    (gitea/pr-merge! gp-forge "alice" "proj" 1 "alice" {})
    :error)
  "not-open")
(gitea-pr-test
  "review after merge rejected"
  (get
    (gitea/pr-review!
      gp-forge
      "alice"
      "proj"
      1
      "carol"
      "approve"
      ""
      {})
    :error)
  "not-open")

; ── merge: fast-forward ──────────────────────────────────────────────

(git/checkout! gp-g "main")
(git/branch! gp-g "hot")
(git/checkout! gp-g "hot")
(git/add! gp-g "hotfix.txt" "fix\n")
(define gp-c4 (git/commit! gp-g {:message "hotfix" :time 9 :author "bob"}))
(git/checkout! gp-g "main")

(define
  gp-pr3
  (gitea/pr-create!
    gp-forge
    "alice"
    "proj"
    "bob"
    "Hotfix"
    "hot"
    "main"
    ""
    {}))
(gitea-pr-test "pr3 number" (get gp-pr3 :number) 3)
(gitea/pr-review!
  gp-forge
  "alice"
  "proj"
  3
  "carol"
  "approve"
  ""
  {})
(define
  gp-m3
  (gitea/pr-merge! gp-forge "alice" "proj" 3 "alice" {}))
(gitea-pr-test "ff merge state" (get gp-m3 :state) "merged")
(gitea-pr-test
  "ff moves main to source head"
  (git/branch-get gp-g "main")
  gp-c4)
(gitea-pr-test "ff merge-cid is source head" (get gp-m3 :merge-cid) gp-c4)

; ── merge: up-to-date ────────────────────────────────────────────────

(git/checkout! gp-g "main")
(git/branch! gp-g "same")
(define
  gp-pr4
  (gitea/pr-create!
    gp-forge
    "alice"
    "proj"
    "bob"
    "No-op"
    "same"
    "main"
    ""
    {}))
(gitea/pr-review!
  gp-forge
  "alice"
  "proj"
  4
  "carol"
  "approve"
  ""
  {})
(define
  gp-m4
  (gitea/pr-merge! gp-forge "alice" "proj" 4 "alice" {}))
(gitea-pr-test "up-to-date merge state" (get gp-m4 :state) "merged")
(gitea-pr-test "up-to-date leaves main" (git/branch-get gp-g "main") gp-c4)

; ── merge: conflicts ─────────────────────────────────────────────────

(git/checkout! gp-g "main")
(git/branch! gp-g "conf")
(git/checkout! gp-g "conf")
(git/add! gp-g "lib.txt" "conf version\n")
(git/commit! gp-g {:message "conf change" :time 10 :author "bob"})
(git/checkout! gp-g "main")
(git/add! gp-g "lib.txt" "main version\n")
(git/commit! gp-g {:message "main change" :time 11 :author "alice"})

(define
  gp-pr5
  (gitea/pr-create!
    gp-forge
    "alice"
    "proj"
    "bob"
    "Conflicting"
    "conf"
    "main"
    ""
    {}))
(gitea/pr-review!
  gp-forge
  "alice"
  "proj"
  5
  "carol"
  "approve"
  ""
  {})
(define
  gp-m5
  (gitea/pr-merge! gp-forge "alice" "proj" 5 "alice" {}))
(gitea-pr-test "conflict merge errors" (get gp-m5 :error) "conflicts")
(gitea-pr-test "conflict paths" (get gp-m5 :conflicts) (list "lib.txt"))
(gitea-pr-test
  "conflict leaves pr open"
  (get (gitea/pr-get gp-forge "alice" "proj" 5) :state)
  "open")
(gitea-pr-test
  "conflict leaves flow at approved"
  (gitea/pr-flow-status
    gp-forge
    (gitea/pr-get gp-forge "alice" "proj" 5))
  "approved")

; ── close / reopen ───────────────────────────────────────────────────

(gitea/pr-close! gp-forge "alice" "proj" 5)
(gitea-pr-test
  "close state"
  (get (gitea/pr-get gp-forge "alice" "proj" 5) :state)
  "closed")
(gitea-pr-test
  "close cancels flow"
  (gitea/pr-flow-status
    gp-forge
    (gitea/pr-get gp-forge "alice" "proj" 5))
  "closed")
(gitea-pr-test
  "merge closed pr rejected"
  (get
    (gitea/pr-merge! gp-forge "alice" "proj" 5 "alice" {})
    :error)
  "not-open")
(gitea-pr-test
  "close twice"
  (gitea/pr-close! gp-forge "alice" "proj" 5)
  nil)

(gitea/pr-reopen! gp-forge "alice" "proj" 5)
(gitea-pr-test
  "reopen state"
  (get (gitea/pr-get gp-forge "alice" "proj" 5) :state)
  "open")
(gitea-pr-test
  "reopen restarts lifecycle"
  (gitea/pr-flow-status
    gp-forge
    (gitea/pr-get gp-forge "alice" "proj" 5))
  "review")

; ── merge queue ──────────────────────────────────────────────────────

(git/checkout! gp-g "main")
(git/branch! gp-g "q1")
(git/checkout! gp-g "q1")
(git/add! gp-g "q1.txt" "one\n")
(git/commit! gp-g {:message "q1" :time 12 :author "bob"})
(git/checkout! gp-g "main")
(git/branch! gp-g "q2")
(git/checkout! gp-g "q2")
(git/add! gp-g "q2.txt" "two\n")
(git/commit! gp-g {:message "q2" :time 13 :author "bob"})
(git/checkout! gp-g "main")
(git/branch! gp-g "q3")
(git/checkout! gp-g "q3")
(git/add! gp-g "q3.txt" "three\n")
(git/commit! gp-g {:message "q3" :time 14 :author "bob"})
(git/checkout! gp-g "main")

(define
  gp-pr6
  (gitea/pr-create!
    gp-forge
    "alice"
    "proj"
    "bob"
    "Queue one"
    "q1"
    "main"
    ""
    {}))
(define
  gp-pr7
  (gitea/pr-create!
    gp-forge
    "alice"
    "proj"
    "bob"
    "Queue two"
    "q2"
    "main"
    ""
    {}))
(define
  gp-pr8
  (gitea/pr-create!
    gp-forge
    "alice"
    "proj"
    "bob"
    "Queue three"
    "q3"
    "main"
    ""
    {}))
(gitea/pr-review!
  gp-forge
  "alice"
  "proj"
  6
  "carol"
  "approve"
  ""
  {})
(gitea/pr-review!
  gp-forge
  "alice"
  "proj"
  7
  "carol"
  "approve"
  ""
  {})
; pr8 stays unapproved; pr5 (reopened, approved, conflicting) joins the queue

(gitea-pr-test
  "queue starts empty"
  (gitea/queue gp-forge "alice" "proj")
  (list))
(gitea-pr-test
  "queue rejects unapproved"
  (get (gitea/queue-add! gp-forge "alice" "proj" 8) :error)
  "not-approved")
(gitea-pr-test
  "queue rejects missing"
  (get (gitea/queue-add! gp-forge "alice" "proj" 99) :error)
  "no-such-pr")

(gitea/queue-add! gp-forge "alice" "proj" 6)
(gitea/queue-add! gp-forge "alice" "proj" 6)
(gitea/queue-add! gp-forge "alice" "proj" 7)
(gitea/queue-add! gp-forge "alice" "proj" 5)
(gitea-pr-test
  "queue dedups"
  (gitea/queue gp-forge "alice" "proj")
  (list 6 7 5))

(define gp-qres (gitea/queue-process! gp-forge "alice" "proj" "alice"))
(gitea-pr-test "queue processed all" (len gp-qres) 3)
(gitea-pr-test
  "queue pr6 merged"
  (get (nth gp-qres 0) :merged)
  true)
(gitea-pr-test
  "queue pr7 merged"
  (get (nth gp-qres 1) :merged)
  true)
(gitea-pr-test
  "queue pr5 conflicts"
  (get (nth gp-qres 2) :error)
  "conflicts")
(gitea-pr-test
  "failures stay queued"
  (gitea/queue gp-forge "alice" "proj")
  (list 5))
(gitea-pr-test
  "pr6 state merged"
  (get (gitea/pr-get gp-forge "alice" "proj" 6) :state)
  "merged")
(gitea-pr-test
  "pr7 state merged"
  (get (gitea/pr-get gp-forge "alice" "proj" 7) :state)
  "merged")
(gitea-pr-test
  "main has both queue files"
  (get (gitea/tree-at gp-g (git/branch-get gp-g "main") "q2.txt") :kind)
  "blob")

(gitea/queue-remove! gp-forge "alice" "proj" 5)
(gitea-pr-test "queue-remove!" (gitea/queue gp-forge "alice" "proj") (list))

; ── web routes ───────────────────────────────────────────────────────

(define gp-app (gitea/app gp-forge))
(define gp-hdr (fn (tok) (if (nil? tok) {} {:authorization (str "Bearer " tok)})))
(define
  gp-get
  (fn (target tok) (gp-app (dream-request "GET" target (gp-hdr tok) ""))))
(define
  gp-post
  (fn
    (target tok body)
    (gp-app (dream-request "POST" target (gp-hdr tok) body))))

(gitea-pr-test
  "pulls page 200"
  (dream-status (gp-get "/alice/proj/pulls" nil))
  200)
(gitea-pr-test
  "pulls page shows title"
  (contains?
    (dream-resp-body (gp-get "/alice/proj/pulls" nil))
    "Add feature")
  true)
(gitea-pr-test
  "pulls page shows state"
  (contains? (dream-resp-body (gp-get "/alice/proj/pulls" nil)) "[merged]")
  true)

(gitea-pr-test
  "pull page 200"
  (dream-status (gp-get "/alice/proj/pulls/1" nil))
  200)
(gitea-pr-test
  "pull page shows branches"
  (contains?
    (dream-resp-body (gp-get "/alice/proj/pulls/1" nil))
    "feat -> main")
  true)
(gitea-pr-test
  "pull page renders body"
  (contains? (dream-resp-body (gp-get "/alice/proj/pulls/1" nil)) "<p>")
  true)
(gitea-pr-test
  "pull page shows review verdict"
  (contains?
    (dream-resp-body (gp-get "/alice/proj/pulls/1" nil))
    "carol: approve")
  true)
(gitea-pr-test
  "pull page shows lifecycle"
  (contains? (dream-resp-body (gp-get "/alice/proj/pulls/1" nil)) "merged")
  true)
(gitea-pr-test
  "pull page bad number 404"
  (dream-status (gp-get "/alice/proj/pulls/abc" nil))
  404)
(gitea-pr-test
  "pull page missing 404"
  (dream-status (gp-get "/alice/proj/pulls/99" nil))
  404)
(gitea-pr-test
  "private pulls anon 404"
  (dream-status (gp-get "/alice/sec/pulls" nil))
  404)

(gitea-pr-test
  "api pulls len"
  (len
    (dream-json-parse
      (dream-resp-body (gp-get "/api/repos/alice/proj/pulls" nil))))
  7)
(gitea-pr-test
  "api pulls first source"
  (get
    (first
      (dream-json-parse
        (dream-resp-body (gp-get "/api/repos/alice/proj/pulls" nil))))
    :source)
  "feat")

(gitea-pr-test
  "api create anon 401"
  (dream-status
    (gp-post "/api/repos/alice/proj/pulls" nil (dream-json-encode {:source "q3" :title "t" :target "main"})))
  401)
(gitea-pr-test
  "api create 201"
  (dream-status
    (gp-post
      "/api/repos/alice/proj/pulls"
      "tok-e"
      (dream-json-encode {:source "q3" :title "Eve PR" :body "please" :target "main"})))
  201)
(gitea-pr-test
  "api create bad source 400"
  (dream-status
    (gp-post
      "/api/repos/alice/proj/pulls"
      "tok-e"
      (dream-json-encode {:source "zz" :title "t" :target "main"})))
  400)

; eve's PR is #9
(gitea-pr-test
  "api review 200"
  (dream-status
    (gp-post
      "/api/repos/alice/proj/pulls/9/reviews"
      "tok-c"
      (dream-json-encode {:verdict "approve" :body "ok"})))
  200)
(gitea-pr-test
  "api self-review 400"
  (dream-status
    (gp-post
      "/api/repos/alice/proj/pulls/9/reviews"
      "tok-e"
      (dream-json-encode {:verdict "approve"})))
  400)
(gitea-pr-test
  "api review anon 401"
  (dream-status
    (gp-post
      "/api/repos/alice/proj/pulls/9/reviews"
      nil
      (dream-json-encode {:verdict "approve"})))
  401)
(gitea-pr-test
  "api review missing pr 404"
  (dream-status
    (gp-post
      "/api/repos/alice/proj/pulls/99/reviews"
      "tok-c"
      (dream-json-encode {:verdict "approve"})))
  404)

(gitea-pr-test
  "api merge reader 403"
  (dream-status (gp-post "/api/repos/alice/proj/pulls/9/merge" "tok-e" "{}"))
  403)
(gitea-pr-test
  "api merge anon 401"
  (dream-status (gp-post "/api/repos/alice/proj/pulls/9/merge" nil "{}"))
  401)
(gitea-pr-test
  "api merge write 200"
  (dream-status (gp-post "/api/repos/alice/proj/pulls/9/merge" "tok-a" "{}"))
  200)
(gitea-pr-test
  "api merge applied"
  (get (gitea/pr-get gp-forge "alice" "proj" 9) :state)
  "merged")

; reopened conflicting pr 5 still conflicts over the api
(gitea-pr-test
  "api merge conflict 409"
  (dream-status (gp-post "/api/repos/alice/proj/pulls/5/merge" "tok-a" "{}"))
  409)

; eve authors #10 and may close it herself; carol (reader) may not
(gp-post "/api/repos/alice/proj/pulls" "tok-e" (dream-json-encode {:source "conf" :title "To close" :target "main"}))
(gitea-pr-test
  "api close by reader 403"
  (dream-status (gp-post "/api/repos/alice/proj/pulls/10/close" "tok-c" "{}"))
  403)
(gitea-pr-test
  "api close by author 200"
  (dream-status (gp-post "/api/repos/alice/proj/pulls/10/close" "tok-e" "{}"))
  200)
(gitea-pr-test
  "api close applied"
  (get (gitea/pr-get gp-forge "alice" "proj" 10) :state)
  "closed")
(gitea-pr-test
  "api close again 409"
  (dream-status (gp-post "/api/repos/alice/proj/pulls/10/close" "tok-e" "{}"))
  409)

; queue over the api: pr5 is approved (reviews survive reopen)
(gitea-pr-test
  "api enqueue reader 403"
  (dream-status
    (gp-post "/api/repos/alice/proj/pulls/5/enqueue" "tok-e" "{}"))
  403)
(gitea-pr-test
  "api enqueue 200"
  (dream-status
    (gp-post "/api/repos/alice/proj/pulls/5/enqueue" "tok-a" "{}"))
  200)
(gitea-pr-test
  "api queue json"
  (dream-json-parse
    (dream-resp-body (gp-get "/api/repos/alice/proj/merge-queue" nil)))
  (list 5))
(gitea-pr-test
  "api queue process 200"
  (dream-status
    (gp-post "/api/repos/alice/proj/merge-queue/process" "tok-a" "{}"))
  200)
(gitea-pr-test
  "api queue process reports conflict"
  (get
    (first
      (dream-json-parse
        (dream-resp-body
          (gp-post "/api/repos/alice/proj/merge-queue/process" "tok-a" "{}"))))
    :error)
  "conflicts")