package postgresadmin_test

import (
	"context"
	"errors"
	"strings"
	"sync/atomic"
	"testing"
	"time"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgconn"
	"github.com/jackc/pgx/v5/pgxpool"

	"proxy-pool/internal/adapters/postgresadmin"
	"proxy-pool/internal/domain/adminstate"
)

func TestNewRejectsNilPool(t *testing.T) {
	t.Parallel()

	store, err := postgresadmin.New(nil)
	if store != nil {
		t.Fatalf("New(nil) store = %T, want nil", store)
	}
	if !errors.Is(err, adminstate.ErrInvalidCommand) {
		t.Fatalf("New(nil) error = %v, want ErrInvalidCommand", err)
	}
}

func TestNewRejectsTypedNilPool(t *testing.T) {
	t.Parallel()

	var pool *pgxpool.Pool
	store, err := postgresadmin.New(pool)
	if store != nil || !errors.Is(err, adminstate.ErrInvalidCommand) {
		t.Fatalf("New(typed nil) = %T, %v, want nil, ErrInvalidCommand", store, err)
	}
}

func TestOperationsPrioritizeCanceledContext(t *testing.T) {
	t.Parallel()

	pool := &countingPool{}
	store, err := postgresadmin.New(pool)
	if err != nil {
		t.Fatalf("New(): %v", err)
	}
	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	operations := []struct {
		name string
		run  func() error
	}{
		{name: "commit config", run: func() error {
			_, operationErr := store.CommitConfig(ctx, adminstate.CommitConfigCommand{})
			return operationErr
		}},
		{name: "set upstream", run: func() error {
			_, operationErr := store.SetUpstreamEnabled(ctx, adminstate.SetUpstreamCommand{})
			return operationErr
		}},
		{name: "switch routing", run: func() error {
			_, operationErr := store.SwitchRouting(ctx, adminstate.SwitchRoutingCommand{})
			return operationErr
		}},
		{name: "disable routing", run: func() error {
			_, operationErr := store.DisableRouting(ctx, adminstate.DisableRoutingCommand{})
			return operationErr
		}},
		{name: "snapshot", run: func() error {
			_, operationErr := store.Snapshot(ctx)
			return operationErr
		}},
		{name: "read audit", run: func() error {
			_, operationErr := store.ReadAudit(ctx, adminstate.AuditQuery{})
			return operationErr
		}},
		{name: "claim", run: func() error {
			_, operationErr := store.Claim(ctx, adminstate.ClaimCommand{})
			return operationErr
		}},
		{name: "acknowledge", run: func() error {
			return store.Acknowledge(ctx, adminstate.AcknowledgeCommand{})
		}},
	}

	for _, operation := range operations {
		operation := operation
		t.Run(operation.name, func(t *testing.T) {
			if operationErr := operation.run(); !errors.Is(operationErr, context.Canceled) {
				t.Fatalf("operation error = %v, want context.Canceled", operationErr)
			}
		})
	}
	if begins := pool.begins.Load(); begins != 0 {
		t.Fatalf("BeginTx calls = %d, want 0", begins)
	}
}

func TestInvalidOperationsDoNotBeginTransaction(t *testing.T) {
	t.Parallel()

	pool := &countingPool{}
	store, err := postgresadmin.New(pool)
	if err != nil {
		t.Fatalf("New(): %v", err)
	}
	operations := []struct {
		name string
		run  func() error
	}{
		{name: "commit config", run: func() error {
			_, operationErr := store.CommitConfig(context.Background(), adminstate.CommitConfigCommand{})
			return operationErr
		}},
		{name: "set upstream", run: func() error {
			_, operationErr := store.SetUpstreamEnabled(context.Background(), adminstate.SetUpstreamCommand{})
			return operationErr
		}},
		{name: "switch routing", run: func() error {
			_, operationErr := store.SwitchRouting(context.Background(), adminstate.SwitchRoutingCommand{})
			return operationErr
		}},
		{name: "disable routing", run: func() error {
			_, operationErr := store.DisableRouting(context.Background(), adminstate.DisableRoutingCommand{})
			return operationErr
		}},
		{name: "read audit", run: func() error {
			_, operationErr := store.ReadAudit(context.Background(), adminstate.AuditQuery{})
			return operationErr
		}},
		{name: "claim", run: func() error {
			_, operationErr := store.Claim(context.Background(), adminstate.ClaimCommand{})
			return operationErr
		}},
		{name: "acknowledge", run: func() error {
			return store.Acknowledge(context.Background(), adminstate.AcknowledgeCommand{})
		}},
	}
	for _, operation := range operations {
		operation := operation
		t.Run(operation.name, func(t *testing.T) {
			if operationErr := operation.run(); !errors.Is(operationErr, adminstate.ErrInvalidCommand) {
				t.Fatalf("operation error = %v, want ErrInvalidCommand", operationErr)
			}
		})
	}
	if begins := pool.begins.Load(); begins != 0 {
		t.Fatalf("BeginTx calls = %d, want 0", begins)
	}
}

func TestDatabaseErrorsAreMappedAndRedacted(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name string
		err  error
		want error
	}{
		{
			name: "connection",
			err:  errors.New("postgres://admin:secret@database/private SQL payload"),
			want: adminstate.ErrUnavailable,
		},
		{
			name: "unique constraint",
			err: &pgconn.PgError{
				Code:    "23505",
				Message: "duplicate cfg-sensitive at postgres://admin:secret@database",
			},
			want: adminstate.ErrConflict,
		},
		{
			name: "foreign key constraint",
			err: &pgconn.PgError{
				Code:    "23503",
				Message: "backend revision reference failed with secret details",
			},
			want: adminstate.ErrUnavailable,
		},
		{
			name: "check constraint",
			err: &pgconn.PgError{
				Code:    "23514",
				Message: "backend invariant failed with secret details",
			},
			want: adminstate.ErrUnavailable,
		},
		{
			name: "value too long",
			err: &pgconn.PgError{
				Code:    "22001",
				Message: "backend encoding failed with secret details",
			},
			want: adminstate.ErrUnavailable,
		},
	}
	for _, test := range tests {
		test := test
		t.Run(test.name, func(t *testing.T) {
			t.Parallel()
			store, err := postgresadmin.New(&errorPool{err: test.err})
			if err != nil {
				t.Fatalf("New(): %v", err)
			}
			_, operationErr := store.CommitConfig(context.Background(), validConfigCommand())
			if !errors.Is(operationErr, test.want) {
				t.Fatalf("CommitConfig() error = %v, want %v", operationErr, test.want)
			}
			for _, secret := range []string{"secret", "private SQL", "cfg-sensitive", "postgres://"} {
				if strings.Contains(operationErr.Error(), secret) {
					t.Fatalf("CommitConfig() error leaked %q: %v", secret, operationErr)
				}
			}
		})
	}
}

type countingPool struct {
	begins atomic.Int64
}

func (pool *countingPool) BeginTx(context.Context, pgx.TxOptions) (pgx.Tx, error) {
	pool.begins.Add(1)
	return nil, errors.New("unexpected transaction")
}

type errorPool struct {
	err error
}

func (pool *errorPool) BeginTx(context.Context, pgx.TxOptions) (pgx.Tx, error) {
	return nil, pool.err
}

func validConfigCommand() adminstate.CommitConfigCommand {
	return adminstate.CommitConfigCommand{
		RequestID:     "request-a",
		Actor:         adminstate.Actor{ID: "admin-a", SourceIP: "192.0.2.10"},
		OccurredAt:    time.Date(2026, 7, 30, 10, 0, 0, 0, time.UTC),
		ConfigVersion: "cfg-sensitive",
		Checksum:      strings.Repeat("a", adminstate.SHA256HexBytes),
		Source:        "configs/proxy-pool.yaml",
	}
}