Merge pull request 'feat: add backend pagination for infinite scroll in issues and pulls' (#66) from feature/pagination-infinite-scroll into master

internal/gitea/client.go

@@ -308,173 +308,243 @@ func (c *Client) ListOrgsAndRepos(ctx context.Context, token string) (map[string
 	return result, nil
 }
 
-// ListAllIssues fetches all open issues across all repos in the given orgs,
-// using concurrent requests with a semaphore.
-func (c *Client) ListAllIssues(ctx context.Context, token string, orgs []string) ([]Issue, error) {
-	cacheKey := fmt.Sprintf("issues-%s", strings.Join(orgs, ","))
-	if cached, ok := c.getFromCache(cacheKey); ok {
-		return cached.([]Issue), nil
-	}
+// PageSize is the number of items returned per page for paginated listings.
+const PageSize = 20
 
-	// First, collect all repos for the given orgs.
-	var allRepos []Repo
-	for _, org := range orgs {
-		repos, err := c.ListOrgRepos(ctx, token, org)
-		if err != nil {
-			return nil, fmt.Errorf("listing repos for %s: %w", org, err)
-		}
-		allRepos = append(allRepos, repos...)
-	}
-
-	// Fan out issue fetching across repos.
-	var allIssues []Issue
-	var mu sync.Mutex
-	sem := make(chan struct{}, c.maxConcurrent)
-	var wg sync.WaitGroup
-	var firstErr error
-
-	for _, repo := range allRepos {
-		wg.Add(1)
-		go func(r Repo) {
-			defer wg.Done()
-			sem <- struct{}{}
-			defer func() { <-sem }()
-
-			path := fmt.Sprintf("/repos/%s/issues?state=open&type=issues&limit=50", r.FullName)
-			resp, err := c.doRequest(ctx, token, http.MethodGet, path, nil)
-			if err != nil {
-				mu.Lock()
-				if firstErr == nil {
-					firstErr = fmt.Errorf("fetching issues for %s: %w", r.FullName, err)
-				}
-				mu.Unlock()
-				return
-			}
-			defer resp.Body.Close()
-
-			var issues []Issue
-			if err := json.NewDecoder(resp.Body).Decode(&issues); err != nil {
-				mu.Lock()
-				if firstErr == nil {
-					firstErr = fmt.Errorf("decoding issues for %s: %w", r.FullName, err)
-				}
-				mu.Unlock()
-				return
-			}
-
-			// Tag each issue with repo info.
-			for i := range issues {
-				issues[i].RepoOwner = r.Owner.Login
-				issues[i].RepoName = r.Name
-			}
-
-			mu.Lock()
-			allIssues = append(allIssues, issues...)
-			mu.Unlock()
-		}(repo)
-	}
-
-	wg.Wait()
-
-	if firstErr != nil {
-		return nil, firstErr
-	}
-
-	// Sort by updated time, newest first.
-	sort.Slice(allIssues, func(i, j int) bool {
-		return allIssues[i].UpdatedAt.After(allIssues[j].UpdatedAt)
-	})
-
-	c.setCache(cacheKey, allIssues)
-	return allIssues, nil
+// PaginatedIssues holds a page of issues along with pagination metadata.
+type PaginatedIssues struct {
+	Issues  []Issue
+	HasMore bool
 }
 
-// ListAllPullRequests fetches all open PRs across all repos in the given orgs.
-func (c *Client) ListAllPullRequests(ctx context.Context, token string, orgs []string) ([]PullRequest, error) {
-	cacheKey := fmt.Sprintf("pulls-%s", strings.Join(orgs, ","))
+// PaginatedPulls holds a page of pull requests along with pagination metadata.
+type PaginatedPulls struct {
+	Pulls   []PullRequest
+	HasMore bool
+}
+
+// ListAllIssues fetches issues across all repos in the given orgs,
+// using concurrent requests with a semaphore. Results are paginated.
+func (c *Client) ListAllIssues(ctx context.Context, token string, orgs []string, state string, page int) (PaginatedIssues, error) {
+	if state == "" {
+		state = "open"
+	}
+	if page < 1 {
+		page = 1
+	}
+
+	cacheKey := fmt.Sprintf("issues-%s-%s", state, strings.Join(orgs, ","))
+	var allIssues []Issue
 	if cached, ok := c.getFromCache(cacheKey); ok {
-		return cached.([]PullRequest), nil
-	}
-
-	var allRepos []Repo
-	for _, org := range orgs {
-		repos, err := c.ListOrgRepos(ctx, token, org)
-		if err != nil {
-			return nil, fmt.Errorf("listing repos for %s: %w", org, err)
-		}
-		allRepos = append(allRepos, repos...)
-	}
-
-	var allPRs []PullRequest
-	var mu sync.Mutex
-	sem := make(chan struct{}, c.maxConcurrent)
-	var wg sync.WaitGroup
-	var firstErr error
-
-	for _, repo := range allRepos {
-		wg.Add(1)
-		go func(r Repo) {
-			defer wg.Done()
-			sem <- struct{}{}
-			defer func() { <-sem }()
-
-			path := fmt.Sprintf("/repos/%s/pulls?state=open&limit=50", r.FullName)
-			resp, err := c.doRequest(ctx, token, http.MethodGet, path, nil)
+		allIssues = cached.([]Issue)
+	} else {
+		// First, collect all repos for the given orgs.
+		var allRepos []Repo
+		for _, org := range orgs {
+			repos, err := c.ListOrgRepos(ctx, token, org)
 			if err != nil {
-				mu.Lock()
-				if firstErr == nil {
-					firstErr = fmt.Errorf("fetching PRs for %s: %w", r.FullName, err)
+				return PaginatedIssues{}, fmt.Errorf("listing repos for %s: %w", org, err)
+			}
+			allRepos = append(allRepos, repos...)
+		}
+
+		// Fan out issue fetching across repos.
+		var mu sync.Mutex
+		sem := make(chan struct{}, c.maxConcurrent)
+		var wg sync.WaitGroup
+		var firstErr error
+
+		for _, repo := range allRepos {
+			wg.Add(1)
+			go func(r Repo) {
+				defer wg.Done()
+				sem <- struct{}{}
+				defer func() { <-sem }()
+
+				path := fmt.Sprintf("/repos/%s/issues?state=%s&type=issues&limit=50", r.FullName, state)
+				resp, err := c.doRequest(ctx, token, http.MethodGet, path, nil)
+				if err != nil {
+					mu.Lock()
+					if firstErr == nil {
+						firstErr = fmt.Errorf("fetching issues for %s: %w", r.FullName, err)
+					}
+					mu.Unlock()
+					return
 				}
-				mu.Unlock()
-				return
-			}
-			defer resp.Body.Close()
+				defer resp.Body.Close()
 
-			var prs []PullRequest
-			if err := json.NewDecoder(resp.Body).Decode(&prs); err != nil {
-				mu.Lock()
-				if firstErr == nil {
-					firstErr = fmt.Errorf("decoding PRs for %s: %w", r.FullName, err)
+				var issues []Issue
+				if err := json.NewDecoder(resp.Body).Decode(&issues); err != nil {
+					mu.Lock()
+					if firstErr == nil {
+						firstErr = fmt.Errorf("decoding issues for %s: %w", r.FullName, err)
+					}
+					mu.Unlock()
+					return
 				}
+
+				// Tag each issue with repo info.
+				for i := range issues {
+					issues[i].RepoOwner = r.Owner.Login
+					issues[i].RepoName = r.Name
+				}
+
+				mu.Lock()
+				allIssues = append(allIssues, issues...)
 				mu.Unlock()
-				return
-			}
+			}(repo)
+		}
 
-			for i := range prs {
-				prs[i].RepoOwner = r.Owner.Login
-				prs[i].RepoName = r.Name
-			}
+		wg.Wait()
 
-			mu.Lock()
-			allPRs = append(allPRs, prs...)
-			mu.Unlock()
-		}(repo)
+		if firstErr != nil {
+			return PaginatedIssues{}, firstErr
+		}
+
+		// Sort by updated time, newest first.
+		sort.Slice(allIssues, func(i, j int) bool {
+			return allIssues[i].UpdatedAt.After(allIssues[j].UpdatedAt)
+		})
+
+		c.setCache(cacheKey, allIssues)
 	}
 
-	wg.Wait()
-
-	if firstErr != nil {
-		return nil, firstErr
+	// Paginate.
+	start := (page - 1) * PageSize
+	if start >= len(allIssues) {
+		return PaginatedIssues{}, nil
+	}
+	end := start + PageSize
+	hasMore := end < len(allIssues)
+	if end > len(allIssues) {
+		end = len(allIssues)
 	}
 
-	sort.Slice(allPRs, func(i, j int) bool {
-		return allPRs[i].UpdatedAt.After(allPRs[j].UpdatedAt)
-	})
+	return PaginatedIssues{Issues: allIssues[start:end], HasMore: hasMore}, nil
+}
 
-	c.setCache(cacheKey, allPRs)
-	return allPRs, nil
+// ListAllPullRequests fetches PRs across all repos in the given orgs.
+// Results are paginated.
+func (c *Client) ListAllPullRequests(ctx context.Context, token string, orgs []string, state string, page int) (PaginatedPulls, error) {
+	if state == "" {
+		state = "open"
+	}
+	if page < 1 {
+		page = 1
+	}
+
+	cacheKey := fmt.Sprintf("pulls-%s-%s", state, strings.Join(orgs, ","))
+	var allPRs []PullRequest
+	if cached, ok := c.getFromCache(cacheKey); ok {
+		allPRs = cached.([]PullRequest)
+	} else {
+		var allRepos []Repo
+		for _, org := range orgs {
+			repos, err := c.ListOrgRepos(ctx, token, org)
+			if err != nil {
+				return PaginatedPulls{}, fmt.Errorf("listing repos for %s: %w", org, err)
+			}
+			allRepos = append(allRepos, repos...)
+		}
+
+		var mu sync.Mutex
+		sem := make(chan struct{}, c.maxConcurrent)
+		var wg sync.WaitGroup
+		var firstErr error
+
+		for _, repo := range allRepos {
+			wg.Add(1)
+			go func(r Repo) {
+				defer wg.Done()
+				sem <- struct{}{}
+				defer func() { <-sem }()
+
+				path := fmt.Sprintf("/repos/%s/pulls?state=%s&limit=50", r.FullName, state)
+				resp, err := c.doRequest(ctx, token, http.MethodGet, path, nil)
+				if err != nil {
+					mu.Lock()
+					if firstErr == nil {
+						firstErr = fmt.Errorf("fetching PRs for %s: %w", r.FullName, err)
+					}
+					mu.Unlock()
+					return
+				}
+				defer resp.Body.Close()
+
+				var prs []PullRequest
+				if err := json.NewDecoder(resp.Body).Decode(&prs); err != nil {
+					mu.Lock()
+					if firstErr == nil {
+						firstErr = fmt.Errorf("decoding PRs for %s: %w", r.FullName, err)
+					}
+					mu.Unlock()
+					return
+				}
+
+				for i := range prs {
+					prs[i].RepoOwner = r.Owner.Login
+					prs[i].RepoName = r.Name
+				}
+
+				mu.Lock()
+				allPRs = append(allPRs, prs...)
+				mu.Unlock()
+			}(repo)
+		}
+
+		wg.Wait()
+
+		if firstErr != nil {
+			return PaginatedPulls{}, firstErr
+		}
+
+		sort.Slice(allPRs, func(i, j int) bool {
+			return allPRs[i].UpdatedAt.After(allPRs[j].UpdatedAt)
+		})
+
+		c.setCache(cacheKey, allPRs)
+	}
+
+	// Paginate.
+	start := (page - 1) * PageSize
+	if start >= len(allPRs) {
+		return PaginatedPulls{}, nil
+	}
+	end := start + PageSize
+	hasMore := end < len(allPRs)
+	if end > len(allPRs) {
+		end = len(allPRs)
+	}
+
+	return PaginatedPulls{Pulls: allPRs[start:end], HasMore: hasMore}, nil
 }
 
 // GetTriageQueue returns unassigned issues and PRs needing review, sorted by priority.
 func (c *Client) GetTriageQueue(ctx context.Context, token string, orgs []string) ([]TriageItem, error) {
-	issues, err := c.ListAllIssues(ctx, token, orgs)
-	if err != nil {
-		return nil, fmt.Errorf("fetching issues for triage: %w", err)
+	// Collect all open issues across all pages.
+	var issues []Issue
+	for page := 1; ; page++ {
+		result, err := c.ListAllIssues(ctx, token, orgs, "open", page)
+		if err != nil {
+			return nil, fmt.Errorf("fetching issues for triage: %w", err)
+		}
+		issues = append(issues, result.Issues...)
+		if !result.HasMore {
+			break
+		}
 	}
 
-	prs, err := c.ListAllPullRequests(ctx, token, orgs)
-	if err != nil {
-		return nil, fmt.Errorf("fetching PRs for triage: %w", err)
+	// Collect all open PRs across all pages.
+	var prs []PullRequest
+	for page := 1; ; page++ {
+		result, err := c.ListAllPullRequests(ctx, token, orgs, "open", page)
+		if err != nil {
+			return nil, fmt.Errorf("fetching PRs for triage: %w", err)
+		}
+		prs = append(prs, result.Pulls...)
+		if !result.HasMore {
+			break
+		}
 	}
 
 	var queue []TriageItem