feat(pr): list pull requests in a table and render issue and pr views as views

tea pr list prints a header, a "Showing N of M" line and the ID, TITLE,
BRANCH, STATE, AUTHOR and CREATED columns on a terminal, fit to its
width, and tab-separated rows when piped. Fork heads read
OWNER:BRANCH, drafts and merged pull requests have their own state,
and STATE appears on a terminal only when --state is not open. New
filters: --state merged, -d/--draft, -H/--head, -a/--assignee,
-S/--search and -w/--web, plus the gh shorthands -s, -A, -B, -l and
-m; --milestone takes a title or an ID, and @me works for --author and
--assignee. An empty list says so on stderr. draft, merged_at and
merged_by are exported in JSON, and reviewers, reviewer_teams and
merged_by, which Gitea's list leaves out, are read when --json names
them.

issue view and pr view render through terminal.View. Pull requests
show Draft and Merged badges, "alice merged into main from fix" with
the merge time, each reviewer's latest state ("bob (Approved), carol
(Requested)"), a checks summary pointing at tea pr checks, and why a
pull request cannot be merged. --comments includes reviews without a
body ("dave approved these changes") and comment IDs. Issues show
their due date and ref, and both kinds hint at --comments when there
are comments. pr view accepts #N, URLs and branch names, and its JSON
adds review_decision. Check links are absolute.

Signed-off-by: bircni <bircni@icloud.com>

internal/services/pulls.go

@@ -11,6 +11,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -21,33 +22,40 @@ import (
 
 // Pull is the stable command representation of a pull request.
 type Pull struct {
-	Author            string          `json:"author"`
-	CreatedAt         string          `json:"created_at"`
-	UpdatedAt         string          `json:"updated_at"`
-	Assignees         []string        `json:"assignees"`
-	Milestone         *IssueMilestone `json:"milestone"`
-	Labels            []Label         `json:"labels"`
-	Deadline          *string         `json:"due_date"`
-	ID                int64           `json:"id"`
-	Number            int64           `json:"number"`
-	Title             string          `json:"title"`
-	Body              string          `json:"body"`
-	URL               string          `json:"url"`
-	State             string          `json:"state"`
-	Merged            bool            `json:"merged"`
-	Mergeable         bool            `json:"mergeable"`
-	Draft             bool            `json:"-"`
-	Base              string          `json:"base"`
-	Head              string          `json:"head"`
-	HeadSHA           string          `json:"head_sha"`
-	HeadRepo          string          `json:"head_repo,omitempty"`
-	HeadRemoteDeleted bool            `json:"head_remote_deleted"`
-	HeadCanPush       bool            `json:"-"`
-	HeadCloneURL      string          `json:"-"`
-	HeadSSHURL        string          `json:"-"`
-	Reviewers         []string        `json:"reviewers"`
-	ReviewerTeams     []string        `json:"reviewer_teams"`
-	Comments          int64           `json:"comments"`
+	Author    string          `json:"author"`
+	CreatedAt string          `json:"created_at"`
+	UpdatedAt string          `json:"updated_at"`
+	Assignees []string        `json:"assignees"`
+	Milestone *IssueMilestone `json:"milestone"`
+	Labels    []Label         `json:"labels"`
+	Deadline  *string         `json:"due_date"`
+	ID        int64           `json:"id"`
+	Number    int64           `json:"number"`
+	Title     string          `json:"title"`
+	Body      string          `json:"body"`
+	URL       string          `json:"url"`
+	State     string          `json:"state"`
+	Merged    bool            `json:"merged"`
+	MergedAt  *string         `json:"merged_at"`
+	// MergedBy, Reviewers and ReviewerTeams are only in responses for one pull request; lists
+	// leave them out.
+	MergedBy  string `json:"merged_by"`
+	Mergeable bool   `json:"mergeable"`
+	Draft     bool   `json:"draft"`
+	// ReviewDecision summarizes the reviews like gh: approved, changes_requested, review_required
+	// or "". Only commands that read the reviews fill it.
+	ReviewDecision    string   `json:"review_decision"`
+	Base              string   `json:"base"`
+	Head              string   `json:"head"`
+	HeadSHA           string   `json:"head_sha"`
+	HeadRepo          string   `json:"head_repo,omitempty"`
+	HeadRemoteDeleted bool     `json:"head_remote_deleted"`
+	HeadCanPush       bool     `json:"-"`
+	HeadCloneURL      string   `json:"-"`
+	HeadSSHURL        string   `json:"-"`
+	Reviewers         []string `json:"reviewers"`
+	ReviewerTeams     []string `json:"reviewer_teams"`
+	Comments          int64    `json:"comments"`
 }
 
 func pullHeadBranch(number int64, ref, label string) (branch string, deleted bool) {
@@ -74,7 +82,8 @@ func pullFrom(pull *gitea.PullRequest) Pull {
 		Author: login(pull.Poster), CreatedAt: timestamp(deref(pull.Created)), UpdatedAt: timestamp(deref(pull.Updated)),
 		Assignees: convertAll(pull.Assignees, login), Milestone: issueMilestoneFrom(pull.Milestone), Labels: convertAll(pull.Labels, labelFrom),
 		Deadline: optionalTimestamp(pull.Deadline), ID: pull.ID, Number: pull.Index, Title: pull.Title, Body: pull.Body,
-		URL: pull.HTMLURL, State: string(pull.State), Merged: pull.HasMerged, Mergeable: pull.Mergeable, Draft: pull.Draft,
+		URL: pull.HTMLURL, State: string(pull.State), Merged: pull.HasMerged, MergedAt: optionalTimestamp(pull.Merged), MergedBy: login(pull.MergedBy),
+		Mergeable: pull.Mergeable, Draft: pull.Draft,
 		Base: base.Ref, Head: headBranch, HeadSHA: head.Sha, HeadRemoteDeleted: remoteDeleted,
 		Reviewers: convertAll(pull.RequestedReviewers, login), Comments: int64(pull.Comments),
 		ReviewerTeams: convertAll(pull.RequestedReviewersTeams, func(team *gitea.Team) string { return team.Name }),
@@ -127,17 +136,71 @@ type Pulls struct {
 	Repository string
 }
 
-// PullListOptions supplies server-supported pull request filters.
+// PullListOptions filters pull requests. State is open, closed, merged or all.
 type PullListOptions struct {
 	State, Sort, Author, Base string
 	Limit, Page               int
 	Milestone                 int64
 	Labels                    []int64
+	// Draft, Head (BRANCH or OWNER:BRANCH), Assignee, Search (text in the title or body) and the
+	// merged state have no server filter; List applies them to every pull request it reads.
+	Draft                  bool
+	Head, Assignee, Search string
+}
+
+// filtered reports whether a filter needs every pull request read.
+func (o PullListOptions) filtered() bool {
+	return o.State == "merged" || o.Draft || o.Head != "" || o.Assignee != "" || o.Search != ""
+}
+
+// matches applies the filters without a server equivalent to item.
+func (o PullListOptions) matches(item Pull) bool {
+	owner, branch, qualified := strings.Cut(o.Head, ":")
+	if !qualified {
+		owner, branch = "", o.Head
+	}
+	headOwner, _, _ := strings.Cut(item.HeadRepo, "/")
+	search := strings.ToLower(o.Search)
+	return (o.State != "merged" || item.Merged) && (!o.Draft || item.Draft) &&
+		(branch == "" || (item.Head == branch && (owner == "" || strings.EqualFold(owner, headOwner)))) &&
+		(o.Assignee == "" || slices.ContainsFunc(item.Assignees, func(name string) bool { return strings.EqualFold(name, o.Assignee) })) &&
+		(search == "" || strings.Contains(strings.ToLower(item.Title), search) || strings.Contains(strings.ToLower(item.Body), search))
 }
 
 // List returns a page of pull requests, even when the server caps its page size below the
 // limit, and reports whether more pull requests follow.
 func (s Pulls) List(ctx context.Context, options PullListOptions) ([]Pull, bool, error) {
+	page, err := s.ListPage(ctx, options)
+	return page.Items, page.More, err
+}
+
+// ListPage is List that also reports how many pull requests match, when the server counts them
+// or every pull request was read for a filter without a server equivalent.
+func (s Pulls) ListPage(ctx context.Context, options PullListOptions) (Page[Pull], error) {
+	if !options.filtered() {
+		return s.listPage(ctx, options)
+	}
+	query := options
+	if query.State == "merged" {
+		query.State = "closed"
+	}
+	all, err := listAll(func(page int) ([]Pull, error) {
+		query.Limit, query.Page = 50, page
+		window, err := s.listPage(ctx, query)
+		return window.Items, err
+	})
+	if err != nil {
+		return Page[Pull]{}, err
+	}
+	matching := slices.DeleteFunc(all, func(item Pull) bool { return !options.matches(item) })
+	items, err := pageOf(matching, options.Limit, options.Page)
+	if err != nil {
+		return Page[Pull]{}, err
+	}
+	return Page[Pull]{Items: items, More: options.Page*options.Limit < len(matching), Total: len(matching), Counted: true}, nil
+}
+
+func (s Pulls) listPage(ctx context.Context, options PullListOptions) (Page[Pull], error) {
 	query := url.Values{"state": {options.State}}
 	if options.Sort != "" {
 		query.Set("sort", options.Sort)
@@ -156,11 +219,11 @@ func (s Pulls) List(ctx context.Context, options PullListOptions) ([]Pull, bool,
 	}
 
 	// TODO(sdk): ListPullRequestsOptions lacks the poster, base_branch, and labels filters.
-	pulls, more, err := rawWindow[*gitea.PullRequest](ctx, s.Client, "repos/"+s.Repository+"/pulls", query, options.Limit, options.Page)
+	page, err := rawPage[*gitea.PullRequest](ctx, s.Client, "repos/"+s.Repository+"/pulls", query, options.Limit, options.Page)
 	if err != nil {
-		return nil, false, err
+		return Page[Pull]{}, err
 	}
-	return convertAll(pulls, pullFrom), more, nil
+	return Page[Pull]{Items: convertAll(page.Items, pullFrom), More: page.More, Total: page.Total, Counted: page.Counted}, nil
 }
 
 // View retrieves one pull request.