// call_monitor: telemetria de invocaciones del agente al fn_registry.
// Issue 0085. Persiste eventos en operations.db local. Hook PostToolUse (0085b)
// y wrapper Python (0085c) escriben aqui. registry_dashboard lee via sqlite_api.
package main

import (
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"text/tabwriter"
)

const defaultDBName = "operations.db"

func main() {
	if len(os.Args) < 2 {
		usage()
		os.Exit(2)
	}
	sub := os.Args[1]

	fs := flag.NewFlagSet(sub, flag.ExitOnError)
	dbPath := fs.String("db", "", "Path to operations.db (default: ./operations.db relative to this binary's directory).")

	switch sub {
	case "init":
		fs.Parse(os.Args[2:])
		runInit(resolveDB(*dbPath))
	case "status":
		topN := fs.Int("top", 10, "Top N functions to list.")
		fs.Parse(os.Args[2:])
		runStatus(resolveDB(*dbPath), *topN)
	case "snapshot":
		registry := fs.String("registry", "", "Path to registry.db (default: walk up from cwd until found).")
		fs.Parse(os.Args[2:])
		runSnapshot(resolveDB(*dbPath), *registry)
	case "copied-code":
		root := fs.String("root", "", "Path to fn_registry root (default: walk up from cwd until registry.db found).")
		fs.Parse(os.Args[2:])
		runCopiedCode(resolveDB(*dbPath), *root)
	case "propose":
		root := fs.String("root", "", "Path to fn_registry root (default: walk up from cwd).")
		dry := fs.Bool("dry-run", false, "Generate drafts without persisting to registry.db.proposals.")
		fs.Parse(os.Args[2:])
		runPropose(*root, *dry)
	case "sequences":
		detect := fs.Bool("detect", false, "Run sequence detection (required).")
		report := fs.Bool("report", false, "Print human-readable report (implied when --propose is not set).")
		propose := fs.Bool("propose", false, "Write new_pipeline proposals to registry.db for uncovered candidates.")
		formatJSON := fs.Bool("format", false, "Output JSON instead of text (use with --report or --detect).")
		root := fs.String("root", "", "Path to fn_registry root (default: walk up from cwd).")
		minOcc := fs.Int("min-occurrences", 5, "Minimum occurrences to be a candidate.")
		windowSecs := fs.Int("window-secs", 30, "Max gap in seconds between consecutive calls in a sequence.")
		lookbackDays := fs.Int("lookback-days", 30, "How many days of calls to scan.")
		fs.Parse(os.Args[2:])
		cfg := SequenceConfig{
			WindowSecs:     *windowSecs,
			LookbackDays:   *lookbackDays,
			MinOccurrences: *minOcc,
			MinSessions:    2,
			MinSuccessRate: 0.9,
		}
		runSequences(resolveDB(*dbPath), *detect, *report, *propose, *formatJSON, *root, cfg)
	case "-h", "--help", "help":
		usage()
	default:
		fmt.Fprintf(os.Stderr, "unknown subcommand: %s\n\n", sub)
		usage()
		os.Exit(2)
	}
}

func usage() {
	fmt.Fprintln(os.Stderr, `call_monitor — telemetria de invocaciones del agente al fn_registry

USO:
  call_monitor <subcomando> [flags]

SUBCOMANDOS:
  init         Crea/abre operations.db y aplica migraciones (idempotente).
  status       Resumen: conteo de filas por tabla + top funciones por calls_total.
  snapshot     Lee registry.db.functions y snapshotea (function_id, content_hash) en
               function_versions con source='index'. Idempotente: solo inserta nuevas tuplas.
  sequences    Detecta secuencias A→B(→C) repetidas candidatas a pipeline one-shot.
               --detect            Ejecutar deteccion (obligatorio).
               --report            Imprimir reporte human-readable (default cuando no se usa --propose).
               --propose           Escribir proposals new_pipeline a registry.db.
               --format            Output JSON en vez de texto.
               --min-occurrences N Minimo de ocurrencias para ser candidata (default 5).
               --window-secs N     Max gap en segundos entre calls consecutivas (default 30).
               --lookback-days N   Dias de historial a escanear (default 30).

FLAGS GLOBALES:
  --db PATH         Ruta a operations.db (default: ./operations.db junto al binario).
  --registry PATH   (subcomando snapshot) Ruta a registry.db. Default: walk up.

EJEMPLOS:
  call_monitor init
  call_monitor status --top 20
  call_monitor snapshot
  call_monitor snapshot --registry /home/lucas/fn_registry/registry.db
  call_monitor sequences --detect --report
  call_monitor sequences --detect --propose
  call_monitor sequences --detect --report --format --min-occurrences 3`)
}

func resolveRegistryDB(override string) string {
	if override != "" {
		return override
	}
	exe, err := os.Executable()
	if err != nil {
		return "registry.db"
	}
	dir := filepath.Dir(exe)
	for {
		candidate := filepath.Join(dir, "registry.db")
		if _, err := os.Stat(candidate); err == nil {
			return candidate
		}
		parent := filepath.Dir(dir)
		if parent == dir {
			break
		}
		dir = parent
	}
	return "registry.db"
}

func resolveRegistryRoot(override string) string {
	if override != "" {
		return override
	}
	exe, err := os.Executable()
	if err != nil {
		return "."
	}
	dir := filepath.Dir(exe)
	for {
		if _, err := os.Stat(filepath.Join(dir, "registry.db")); err == nil {
			return dir
		}
		parent := filepath.Dir(dir)
		if parent == dir {
			break
		}
		dir = parent
	}
	return "."
}

func runCopiedCode(callDBPath, rootOverride string) {
	db, err := openDB(callDBPath)
	if err != nil {
		fmt.Fprintf(os.Stderr, "error: open call_monitor db: %v\n", err)
		os.Exit(1)
	}
	defer db.Close()

	root := resolveRegistryRoot(rootOverride)
	if _, err := os.Stat(filepath.Join(root, "registry.db")); err != nil {
		fmt.Fprintf(os.Stderr, "error: registry.db not found under %s\n", root)
		os.Exit(1)
	}

	inserted, total, err := persistCopiedCode(db, root)
	if err != nil {
		fmt.Fprintf(os.Stderr, "error: copied-code: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("copied-code: %d total match(es) detected, %d newly inserted into copied_code.\n", total, inserted)
}

func runSnapshot(callDBPath, registryOverride string) {
	db, err := openDB(callDBPath)
	if err != nil {
		fmt.Fprintf(os.Stderr, "error: open call_monitor db: %v\n", err)
		os.Exit(1)
	}
	defer db.Close()

	registryPath := resolveRegistryDB(registryOverride)
	if _, err := os.Stat(registryPath); err != nil {
		fmt.Fprintf(os.Stderr, "error: registry.db not found at %s\n", registryPath)
		os.Exit(1)
	}

	inserted, seen, err := snapshotFromRegistry(db, registryPath)
	if err != nil {
		fmt.Fprintf(os.Stderr, "error: snapshot: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("snapshot: %d new versions inserted (out of %d functions seen with content_hash)\n", inserted, seen)
}

func resolveDB(override string) string {
	if override != "" {
		return override
	}
	exe, err := os.Executable()
	if err == nil {
		return filepath.Join(filepath.Dir(exe), defaultDBName)
	}
	return defaultDBName
}

func runInit(path string) {
	db, err := openDB(path)
	if err != nil {
		fmt.Fprintf(os.Stderr, "error: %v\n", err)
		os.Exit(1)
	}
	defer db.Close()
	abs, _ := filepath.Abs(path)
	fmt.Printf("call_monitor.operations.db ready: %s\n", abs)
}

func runStatus(path string, topN int) {
	db, err := openDB(path)
	if err != nil {
		fmt.Fprintf(os.Stderr, "error: %v\n", err)
		os.Exit(1)
	}
	defer db.Close()

	counts, err := db.tableCounts()
	if err != nil {
		fmt.Fprintf(os.Stderr, "table counts: %v\n", err)
		os.Exit(1)
	}

	tw := tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
	fmt.Fprintln(tw, "=== Tables ===")
	fmt.Fprintln(tw, "TABLE\tROWS")
	for _, c := range counts {
		fmt.Fprintf(tw, "%s\t%d\n", c.Name, c.Rows)
	}
	tw.Flush()

	top, err := db.topFunctions(topN)
	if err != nil {
		fmt.Fprintf(os.Stderr, "top functions: %v\n", err)
		os.Exit(1)
	}
	fmt.Println()
	tw = tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
	fmt.Fprintf(tw, "=== Top %d functions (by calls_total) ===\n", topN)
	if len(top) == 0 {
		fmt.Fprintln(tw, "(no calls recorded yet)")
		tw.Flush()
		return
	}
	fmt.Fprintln(tw, "FUNCTION_ID\tCALLS\tCALLS_7D\tERRORS\tERROR_RATE\tMEAN_MS\tLAST_USED_TS")
	for _, s := range top {
		last := ""
		if s.LastUsedAt.Valid {
			last = fmt.Sprintf("%d", s.LastUsedAt.Int64)
		}
		fmt.Fprintf(tw, "%s\t%d\t%d\t%d\t%.2f\t%.0f\t%s\n",
			s.FunctionID, s.CallsTotal, s.Calls7d, s.ErrorsTotal, s.ErrorRate, s.MeanDurationMs, last)
	}
	tw.Flush()
}