feat: parse all Go CLIs with flaggy; dump bash complete. (#36)

stdlib flag dropped --hop after the query. One wrapper in internal/cli,
source <(./bin/cli/complete.go bash). Gitea #34.

internal/websearch/args.go

@@ -0,0 +1,63 @@
+package websearch
+
+import (
+	"fmt"
+
+	"github.com/eSlider/2dph/internal/cli"
+	"github.com/integrii/flaggy"
+)
+
+type CLI struct {
+	Query, Site, Lang, Fresh, Category, Engines string
+	Limit                                       int
+	JSONOut, Refresh, Force                     bool
+	TTL                                         float64
+	Timeout                                     int
+}
+
+func NewCLI() CLI {
+	return CLI{Limit: DefaultLimit, TTL: float64(CacheTTL), Timeout: 25}
+}
+
+func Parser() *flaggy.Parser {
+	c := NewCLI()
+	return Bind(&c)
+}
+
+func Bind(c *CLI) *flaggy.Parser {
+	p := cli.New("web-search")
+	p.Description = "SearXNG second source (throttled ≠ absence)"
+	p.Bool(&c.JSONOut, "", "json", "JSON output")
+	p.Bool(&c.Refresh, "", "refresh", "bypass cache")
+	p.Bool(&c.Force, "", "force", "allow PII in query")
+	p.Int(&c.Limit, "n", "limit", "max hits")
+	p.String(&c.Site, "", "site", "restrict to host")
+	p.String(&c.Lang, "", "lang", "language")
+	p.String(&c.Fresh, "", "fresh", "day|week|month|year")
+	p.String(&c.Category, "", "category", "searx category")
+	p.String(&c.Engines, "", "engines", "engine list")
+	p.Float64(&c.TTL, "", "ttl", "cache ttl seconds")
+	p.Int(&c.Timeout, "", "timeout", "http timeout seconds")
+	return p
+}
+
+func ParseArgs(args []string) (CLI, error) {
+	c := NewCLI()
+	p := Bind(&c)
+	var q string
+	p.AddPositionalValue(&q, "query", 1, false, "search query")
+	if err := cli.Parse(p, args); err != nil {
+		return c, err
+	}
+	c.Query = cli.Query(q, p.TrailingArguments)
+	if c.Query == "" {
+		return c, fmt.Errorf("query required")
+	}
+	if c.Limit < 0 {
+		return c, fmt.Errorf("--limit must be a non-negative integer")
+	}
+	if c.Timeout <= 0 {
+		return c, fmt.Errorf("--timeout must be a positive integer")
+	}
+	return c, nil
+}