backend requirements onthe xustomer app

2026-09-07 10:55:11 +05:30
parent 35675d8a9b
commit 1b2690b21a
56 changed files with 13342 additions and 1071 deletions
--- a/scratch/cx_readonly_probe.go
+++ b/scratch/cx_readonly_probe.go
@@ -0,0 +1,174 @@
+//go:build ignore
+
+// Read-only probe of the live `logistics` database for the customer-app work.
+//
+// STRICTLY READ-ONLY. It runs SELECTs against information_schema and a few
+// COUNTs, and nothing else — no DDL, no INSERT, no UPDATE. It exists to answer
+// one question before anybody boots the service against this database:
+//
+//	is migrations.Migrate() actually additive here, or would it collide with
+//	something that already exists?
+//
+// main.go calls Migrate() on startup, so "just run the server and see" is a
+// schema change to a database the Miler app and both consoles are live against.
+// This is the safe half of that check.
+//
+//	go run scratch/cx_readonly_probe.go
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+
+	_ "github.com/lib/pq"
+)
+
+// The tables migrations.Migrate() would create for the customer app.
+var newTables = []string{
+	"serviceablestates",
+	"serviceabledistricts",
+	"pickupslottemplates",
+	"customerbookinglimits",
+	"bookingdestinations",
+	"bookingparcelphotos",
+	"bookingstageevents",
+	"customerrefreshtokens",
+	"customerdevices",
+}
+
+// Columns it would add to existing tables. These are the ones that touch rows
+// the live system already reads.
+var newColumns = map[string][]string{
+	"pickupbookings": {
+		"slotid", "customerstage", "customerstatus",
+		"estimateminrupees", "estimatemaxrupees", "routekm",
+		"pickuptitle", "pickupsub", "cancelreason",
+	},
+	"bookingparcels": {"bookingdestinationid"},
+}
+
+var newSequences = []string{"cx_booking_reference_seq", "cx_tracking_seq"}
+
+func main() {
+	// Credentials come from the environment only. The other probes in this
+	// folder hardcode the production password; that is one more copy of a live
+	// credential in the repository than there needs to be, and this file does
+	// not add another.
+	//
+	//	set -a && . ./.env && set +a && go run scratch/cx_readonly_probe.go
+	host := env("DB_HOST", "")
+	port := env("DB_PORT", "5433")
+	user := env("DB_USER", "")
+	pass := env("DB_PASSWORD", "")
+	name := env("DB_NAME", "logistics")
+
+	if host == "" || user == "" || pass == "" {
+		log.Fatal("set DB_HOST, DB_USER and DB_PASSWORD first — " +
+			"e.g. `set -a && . ./.env && set +a`")
+	}
+
+	dsn := fmt.Sprintf("host=%s user=%s password=%s dbname=%s port=%s sslmode=disable",
+		host, user, pass, name, port)
+
+	db, err := sql.Open("postgres", dsn)
+	if err != nil {
+		log.Fatalf("open: %v", err)
+	}
+	defer db.Close()
+
+	if err := db.Ping(); err != nil {
+		log.Fatalf("ping: %v", err)
+	}
+	fmt.Printf("connected read-only to %s@%s:%s/%s\n\n", user, host, port, name)
+
+	var total int
+	must(db.QueryRow(`SELECT count(*) FROM information_schema.tables
+		WHERE table_schema = 'public'`).Scan(&total))
+	fmt.Printf("existing public tables: %d\n\n", total)
+
+	fmt.Println("── tables the migration would CREATE ──")
+	existing := 0
+	for _, t := range newTables {
+		var n int
+		must(db.QueryRow(`SELECT count(*) FROM information_schema.tables
+			WHERE table_schema = 'public' AND table_name = $1`, t).Scan(&n))
+		if n > 0 {
+			existing++
+			var rows int
+			if err := db.QueryRow(fmt.Sprintf(`SELECT count(*) FROM %q`, t)).Scan(&rows); err != nil {
+				rows = -1
+			}
+			fmt.Printf("  %-24s ALREADY EXISTS (%d rows)\n", t, rows)
+		} else {
+			fmt.Printf("  %-24s absent — would be created\n", t)
+		}
+	}
+
+	fmt.Println("\n── columns the migration would ADD to live tables ──")
+	for table, cols := range newColumns {
+		var tableRows int
+		if err := db.QueryRow(fmt.Sprintf(`SELECT count(*) FROM %q`, table)).Scan(&tableRows); err != nil {
+			fmt.Printf("  %s: could not count rows: %v\n", table, err)
+			continue
+		}
+		fmt.Printf("  %s (%d rows):\n", table, tableRows)
+		for _, col := range cols {
+			var n int
+			must(db.QueryRow(`SELECT count(*) FROM information_schema.columns
+				WHERE table_schema = 'public' AND table_name = $1 AND column_name = $2`,
+				table, col).Scan(&n))
+			state := "absent — would be added"
+			if n > 0 {
+				state = "ALREADY EXISTS"
+			}
+			fmt.Printf("      %-24s %s\n", col, state)
+		}
+	}
+
+	fmt.Println("\n── sequences ──")
+	for _, s := range newSequences {
+		var n int
+		must(db.QueryRow(`SELECT count(*) FROM information_schema.sequences
+			WHERE sequence_schema = 'public' AND sequence_name = $1`, s).Scan(&n))
+		state := "absent — would be created"
+		if n > 0 {
+			state = "ALREADY EXISTS"
+		}
+		fmt.Printf("  %-30s %s\n", s, state)
+	}
+
+	// Anything that would make the migration NOT additive: a name collision on
+	// a table that is not ours, or a column of an incompatible type.
+	fmt.Println("\n── collision check ──")
+	if existing == 0 {
+		fmt.Println("  none — every customer-app table is new to this database")
+	} else {
+		fmt.Printf("  %d of %d target tables already exist; inspect them before migrating\n",
+			existing, len(newTables))
+	}
+
+	// How much live data the additive columns would land on.
+	var bookings, consignments int
+	_ = db.QueryRow(`SELECT count(*) FROM pickupbookings`).Scan(&bookings)
+	_ = db.QueryRow(`SELECT count(*) FROM consignments`).Scan(&consignments)
+	fmt.Printf("\nlive rows that would gain nullable columns: pickupbookings=%d consignments=%d\n",
+		bookings, consignments)
+
+	fmt.Println("\nNOTHING WAS WRITTEN. This probe issues SELECTs only.")
+}
+
+func env(key, fallback string) string {
+	if v := strings.TrimSpace(os.Getenv(key)); v != "" {
+		return v
+	}
+	return fallback
+}
+
+func must(err error) {
+	if err != nil {
+		log.Fatalf("query: %v", err)
+	}
+}