package inventory

import (
	"context"
	"encoding/json"
	"fmt"
	"os"
	"strings"
	"testing"
	"time"

	"github.com/jackc/pgx/v5"
	"golang.org/x/crypto/bcrypt"

	"github.com/novox/mesh-controller/internal/chain"
	"github.com/novox/mesh-controller/internal/store"
)

// ForTest is a fresh inventory in a database of its own, dropped when the test ends.
//
// Exported because the check that this mesh reads what a node sends lives beside the link, and a
// second copy of this would be a second thing to keep true. It takes a *testing.T, so it cannot
// be called from anything that is not a test.
func ForTest(t *testing.T) *Inventory {
	t.Helper()
	admin := os.Getenv("MESH_TEST_POSTGRES")
	if admin == "" {
		t.Skip("no MESH_TEST_POSTGRES; run `make check` to raise one")
	}
	name := fmt.Sprintf("inv_%d_%s", time.Now().UnixNano()%1_000_000,
		strings.ToLower(strings.NewReplacer("/", "", "-", "").Replace(t.Name())))
	if len(name) > 60 {
		name = name[:60]
	}

	// Created already migrated, a copy of a template migrated once (novox/hq issue 591); the Migrate
	// below then finds nothing pending, which it does only if the copy's record matches every migration.
	migrations, err := Migrations()
	if err != nil {
		t.Fatal(err)
	}
	store.CreateMigratedForTest(t, admin, name, migrations)
	busPasswordCostForTest.Store(int32(bcrypt.MinCost))

	cut := strings.LastIndex(admin, "/")
	t.Setenv(store.Variable(Name), admin[:cut]+"/"+name+"?sslmode=disable")

	inv, err := Open(t.Context())
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() {
		inv.Close()
		c, err := pgx.Connect(context.Background(), admin)
		if err != nil {
			return
		}
		defer c.Close(context.Background())
		_, _ = c.Exec(context.Background(), "drop database if exists "+name+" with (force)")
	})
	if err := inv.Ready(t.Context(), 20*time.Second); err != nil {
		t.Fatal(err)
	}

	if _, err := inv.store.Migrate(t.Context(), migrations); err != nil {
		t.Fatal(err)
	}
	// The chain is on the bus in a mesh; in a test it is in memory (ADR 0408).
	c := chain.InMemory(nil)
	// A fresh test chain has nothing to lay out: it is laid out already, as the controller's start leaves a mesh (issue 1121).
	if _, err := c.Builds.CreateRaw(t.Context(), chain.LayoutMarkerKey, []byte(`{}`)); err != nil {
		t.Fatal(err)
	}
	inv.UseChain(c)
	testChains.Store(os.Getenv(store.Variable(Name)), c)
	t.Cleanup(func() { testChains.Delete(os.Getenv(store.Variable(Name))) })
	return inv
}

// RemoveNodeForTest removes a machine's record as a person removing it from the store would: no verb of the
// mesh removes one yet, and what hangs off it must go with it.
func (i *Inventory) RemoveNodeForTest(ctx context.Context, name string) (bool, error) {
	tag, err := i.store.Pool().Exec(ctx, `delete from node where name = $1`, name)
	if err != nil {
		return false, err
	}
	return tag.RowsAffected() == 1, nil
}

// ForTestBefore is ForTest with the store migrated only below migration `number`, and a function that runs the
// rest: for a test of a migration that moves data, which seeds the store as the mesh holds it before the
// migration, migrates, and reads what the migration made of it (novox/hq issue 651).
func ForTestBefore(t *testing.T, number int) (*Inventory, func()) {
	t.Helper()
	admin := os.Getenv("MESH_TEST_POSTGRES")
	if admin == "" {
		t.Skip("no MESH_TEST_POSTGRES; run `make check` to raise one")
	}
	name := fmt.Sprintf("invb_%d_%s", time.Now().UnixNano()%1_000_000,
		strings.ToLower(strings.NewReplacer("/", "", "-", "").Replace(t.Name())))
	if len(name) > 60 {
		name = name[:60]
	}
	all, err := Migrations()
	if err != nil {
		t.Fatal(err)
	}
	var before []store.Migration
	for _, m := range all {
		if m.Number < number {
			before = append(before, m)
		}
	}
	store.CreateMigratedForTest(t, admin, name, before)
	busPasswordCostForTest.Store(int32(bcrypt.MinCost))
	cut := strings.LastIndex(admin, "/")
	t.Setenv(store.Variable(Name), admin[:cut]+"/"+name+"?sslmode=disable")
	inv, err := Open(t.Context())
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() {
		inv.Close()
		c, err := pgx.Connect(context.Background(), admin)
		if err != nil {
			return
		}
		defer c.Close(context.Background())
		_, _ = c.Exec(context.Background(), "drop database if exists "+name+" with (force)")
	})
	if err := inv.Ready(t.Context(), 20*time.Second); err != nil {
		t.Fatal(err)
	}
	// The chain is in memory, for what a test of the store before a migration reads of it.
	c := chain.InMemory(nil)
	// A fresh test chain has nothing to lay out: it is laid out already, as the controller's start leaves a mesh (issue 1121).
	if _, err := c.Builds.CreateRaw(t.Context(), chain.LayoutMarkerKey, []byte(`{}`)); err != nil {
		t.Fatal(err)
	}
	inv.UseChain(c)
	testChains.Store(os.Getenv(store.Variable(Name)), c)
	t.Cleanup(func() { testChains.Delete(os.Getenv(store.Variable(Name))) })
	return inv, func() {
		t.Helper()
		if _, err := inv.store.Migrate(t.Context(), all); err != nil {
			t.Fatal(err)
		}
	}
}

// ExecForTest runs one statement against a test's store, for a fixture no verb of the mesh writes: a row as an
// older migration left it.
func (i *Inventory) ExecForTest(t *testing.T, sql string, args ...any) {
	t.Helper()
	if _, err := i.store.Pool().Exec(t.Context(), sql, args...); err != nil {
		t.Fatalf("%s: %v", sql, err)
	}
}

// QueryForTest reads rows of a test's store, each row's columns as JSON text, for a test that checks what a
// migration left.
func (i *Inventory) QueryForTest(t *testing.T, sql string, args ...any) [][]string {
	t.Helper()
	rows, err := i.store.Pool().Query(t.Context(), sql, args...)
	if err != nil {
		t.Fatalf("%s: %v", sql, err)
	}
	defer rows.Close()
	var out [][]string
	for rows.Next() {
		values, err := rows.Values()
		if err != nil {
			t.Fatal(err)
		}
		row := make([]string, len(values))
		for k, v := range values {
			row[k] = fmt.Sprint(v)
			if b, err := json.Marshal(v); err == nil {
				row[k] = string(b)
			}
		}
		out = append(out, row)
	}
	if err := rows.Err(); err != nil {
		t.Fatal(err)
	}
	return out
}

// PlanValuesForTest runs the pass that keeps the provisioner's plans in the values of the assignments (KeepAssignmentPlans)
// and answers the values that stand, by key: what a reader of the bucket reads.
func (i *Inventory) PlanValuesForTest(t *testing.T) map[string][]byte {
	t.Helper()
	if _, _, err := i.KeepAssignmentPlans(t.Context()); err != nil {
		t.Fatal(err)
	}
	kept, err := i.KeptAssignments(t.Context())
	if err != nil {
		t.Fatal(err)
	}
	out := make(map[string][]byte, len(kept))
	for key, v := range kept {
		out[key] = v.Value
	}
	return out
}