feat: CVF open access paper browser, search, and conference listing

cli/cmd_conferences.go

@@ -0,0 +1,27 @@
+package cli
+
+import (
+	"github.com/spf13/cobra"
+)
+
+func (a *App) conferencesCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "conferences",
+		Short: "List available CVF conferences",
+		Long: `List all conferences available in the CVF open access repository.
+
+Examples:
+  cvf conferences
+  cvf conferences -f json
+  cvf conferences --fields name,year,location`,
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			a.progressf("fetching conference list...")
+			confs, err := a.client.Conferences(cmd.Context())
+			if err != nil {
+				return mapFetchErr(err)
+			}
+			return a.renderOrEmpty(confs, len(confs))
+		},
+	}
+	return cmd
+}

cli/cmd_papers.go

@@ -0,0 +1,36 @@
+package cli
+
+import (
+	"github.com/spf13/cobra"
+)
+
+func (a *App) papersCmd() *cobra.Command {
+	var conference string
+	var year int
+
+	cmd := &cobra.Command{
+		Use:   "papers",
+		Short: "List papers from a CVF conference",
+		Long: `List papers from a CVF open access conference.
+
+Defaults to CVPR 2024 when no flags are given.
+
+Examples:
+  cvf papers
+  cvf papers --conference CVPR --year 2024 --limit 20
+  cvf papers --conference ICCV --year 2023 -f json`,
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			n := a.effectiveLimit(20)
+			a.progressf("fetching papers from %s %d...", conference, year)
+			papers, err := a.client.Papers(cmd.Context(), conference, year, n)
+			if err != nil {
+				return mapFetchErr(err)
+			}
+			return a.renderOrEmpty(papers, len(papers))
+		},
+	}
+
+	cmd.Flags().StringVarP(&conference, "conference", "c", "CVPR", "conference name (CVPR, ICCV, ECCV, WACV)")
+	cmd.Flags().IntVarP(&year, "year", "y", 2024, "conference year")
+	return cmd
+}

cli/cmd_search.go

@@ -0,0 +1,44 @@
+package cli
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+func (a *App) searchCmd() *cobra.Command {
+	var conference string
+	var year int
+
+	cmd := &cobra.Command{
+		Use:   "search <query>",
+		Short: "Search papers by title or author",
+		Long: `Search papers from a CVF conference by title or author name.
+
+The query is matched case-insensitively against each paper's title and author list.
+
+Examples:
+  cvf search "object detection"
+  cvf search --conference ICCV --year 2023 "transformer" --limit 10
+  cvf search "LeCun" --conference CVPR --year 2023`,
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			query := args[0]
+			n := a.effectiveLimit(0)
+			a.progressf("searching %s %d for %q...", conference, year, query)
+			papers, err := a.client.Search(cmd.Context(), query, conference, year, n)
+			if err != nil {
+				return mapFetchErr(err)
+			}
+			if len(papers) == 0 {
+				fmt.Fprintf(cmd.ErrOrStderr(), "no papers matched %q\n", query)
+				return codeError(exitNoData, nil)
+			}
+			return a.renderOrEmpty(papers, len(papers))
+		},
+	}
+
+	cmd.Flags().StringVarP(&conference, "conference", "c", "CVPR", "conference name (CVPR, ICCV, ECCV, WACV)")
+	cmd.Flags().IntVarP(&year, "year", "y", 2024, "conference year")
+	return cmd
+}

cli/errors.go

@@ -0,0 +1,11 @@
+package cli
+
+import (
+	"errors"
+
+	"github.com/tamnd/cvf-cli/cvf"
+)
+
+func isNotFound(err error) bool {
+	return errors.Is(err, cvf.ErrNotFound)
+}

cli/output.go

@@ -0,0 +1,25 @@
+package cli
+
+import (
+	"io"
+
+	"github.com/tamnd/cvf-cli/pkg/render"
+)
+
+// Format aliases so command code reads cleanly.
+type Format = render.Format
+
+const (
+	FormatTable = render.FormatTable
+	FormatJSON  = render.FormatJSON
+	FormatJSONL = render.FormatJSONL
+	FormatCSV   = render.FormatCSV
+	FormatTSV   = render.FormatTSV
+	FormatURL   = render.FormatURL
+	FormatRaw   = render.FormatRaw
+)
+
+// NewRenderer builds a renderer writing to w.
+func NewRenderer(w io.Writer, format Format, fields []string, noHeader bool, tmpl string) *render.Renderer {
+	return render.New(w, format, fields, noHeader, tmpl)
+}

cli/root.go

@@ -2,7 +2,12 @@
 package cli
 
 import (
+	"fmt"
+	"os"
+
+	"github.com/mattn/go-isatty"
 	"github.com/spf13/cobra"
+	"github.com/tamnd/cvf-cli/cvf"
 )
 
 // Build metadata, set via -ldflags at release time.
@@ -12,20 +17,135 @@ var (
 	Date    = "unknown"
 )
 
+// exit codes.
+const (
+	exitError  = 1
+	exitUsage  = 2
+	exitNoData = 3
+)
+
+// ExitError carries a process exit code up to main.
+type ExitError struct {
+	Code int
+	Err  error
+}
+
+func (e *ExitError) Error() string {
+	if e.Err != nil {
+		return e.Err.Error()
+	}
+	return fmt.Sprintf("exit %d", e.Code)
+}
+
+func (e *ExitError) Unwrap() error { return e.Err }
+
+func codeError(code int, err error) error { return &ExitError{Code: code, Err: err} }
+
+// App holds shared state threaded through every command.
+type App struct {
+	client *cvf.Client
+	cfg    cvf.Config
+
+	output   string
+	fields   []string
+	noHeader bool
+	template string
+	limit    int
+	quiet    bool
+}
+
 // Root builds the root command and its subtree.
 func Root() *cobra.Command {
+	app := &App{cfg: cvf.DefaultConfig()}
+
 	root := &cobra.Command{
 		Use:   "cvf",
 		Short: "Browse Computer Vision Foundation conference papers",
-		Long: `Browse Computer Vision Foundation conference papers
+		Long: `cvf reads the CVF open access repository at https://openaccess.thecvf.com/
+It lists papers from CVPR, ICCV, ECCV, WACV and other CVF conferences.
+No API key required — the site is open access.
 
-This is a fresh scaffold. Add your commands here on top of the cvf
-library package, then wire them into Root with root.AddCommand.`,
+cvf is an independent tool and is not affiliated with the CVF or IEEE.`,
 		SilenceUsage:  true,
 		SilenceErrors: true,
+		PersistentPreRunE: func(cmd *cobra.Command, _ []string) error {
+			return app.setup()
+		},
 	}
 
-	root.AddCommand(newVersionCmd())
-	// TODO: root.AddCommand(newGetCmd()), etc.
+	pf := root.PersistentFlags()
+	pf.StringVarP(&app.output, "format", "f", "auto", "output format: table|json|jsonl|csv|tsv|url (auto=table on TTY, jsonl piped)")
+	pf.StringSliceVar(&app.fields, "fields", nil, "comma-separated columns to include")
+	pf.BoolVar(&app.noHeader, "no-header", false, "omit the header row in table/csv/tsv")
+	pf.StringVar(&app.template, "template", "", "Go text/template applied per record")
+	pf.IntVarP(&app.limit, "limit", "n", 0, "limit number of records (0 = command default)")
+	pf.BoolVarP(&app.quiet, "quiet", "q", false, "suppress progress on stderr")
+
+	pf.StringVar(&app.cfg.BaseURL, "base-url", app.cfg.BaseURL, "CVF open access base URL")
+	pf.DurationVar(&app.cfg.Rate, "delay", app.cfg.Rate, "minimum spacing between requests")
+	pf.DurationVar(&app.cfg.Timeout, "timeout", app.cfg.Timeout, "per-request timeout")
+	pf.IntVar(&app.cfg.Retries, "retries", app.cfg.Retries, "retry attempts on 429/5xx")
+	pf.StringVar(&app.cfg.UserAgent, "user-agent", app.cfg.UserAgent, "User-Agent sent with each request")
+
+	root.AddCommand(
+		app.papersCmd(),
+		app.searchCmd(),
+		app.conferencesCmd(),
+		newVersionCmd(),
+	)
 	return root
 }
+
+func (a *App) setup() error {
+	if a.output == "" || a.output == "auto" {
+		if isatty.IsTerminal(os.Stdout.Fd()) {
+			a.output = string(FormatTable)
+		} else {
+			a.output = string(FormatJSONL)
+		}
+	}
+	if !Format(a.output).Valid() {
+		return codeError(exitUsage, fmt.Errorf("unknown output format %q", a.output))
+	}
+	a.client = cvf.NewClient(a.cfg)
+	return nil
+}
+
+func (a *App) render(records any) error {
+	r := NewRenderer(os.Stdout, Format(a.output), a.fields, a.noHeader, a.template)
+	return r.Render(records)
+}
+
+func (a *App) renderOrEmpty(records any, n int) error {
+	if err := a.render(records); err != nil {
+		return err
+	}
+	if n == 0 {
+		return codeError(exitNoData, nil)
+	}
+	return nil
+}
+
+func (a *App) progressf(format string, args ...any) {
+	if a.quiet {
+		return
+	}
+	fmt.Fprintf(os.Stderr, format+"\n", args...)
+}
+
+func mapFetchErr(err error) error {
+	if err == nil {
+		return nil
+	}
+	if isNotFound(err) {
+		return codeError(exitNoData, err)
+	}
+	return codeError(exitError, err)
+}
+
+func (a *App) effectiveLimit(def int) int {
+	if a.limit > 0 {
+		return a.limit
+	}
+	return def
+}