package database

import (
	"context"
	"testing"
	"time"
)

func TestMigrationTimeout(t *testing.T) {
	tests := []struct {
		name string
		env  string
		set  bool
		want time.Duration
	}{
		{"unset defaults to 20m", "", false, 20 * time.Minute},
		{"empty defaults to 20m", "", true, 20 * time.Minute},
		{"explicit 60m", "60m", true, 60 * time.Minute},
		{"seconds", "90s", true, 90 * time.Second},
		{"zero disables", "0", true, 0},
		{"whitespace trimmed", "  30m  ", true, 30 * time.Minute},
		{"invalid falls back to 20m", "not-a-duration", true, 20 * time.Minute},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if tt.set {
				t.Setenv("SILO_MIGRATE_TIMEOUT", tt.env)
			} else {
				// Ensure no ambient value leaks in.
				t.Setenv("SILO_MIGRATE_TIMEOUT", "")
			}
			if got := MigrationTimeout(); got != tt.want {
				t.Fatalf("MigrationTimeout() = %v, want %v", got, tt.want)
			}
		})
	}
}

func TestMigrationContextDeadline(t *testing.T) {
	// A positive timeout yields a context with a deadline.
	t.Setenv("SILO_MIGRATE_TIMEOUT", "50ms")
	ctx, cancel := MigrationContext(context.Background())
	defer cancel()
	if _, ok := ctx.Deadline(); !ok {
		t.Fatal("expected a deadline with a positive timeout")
	}
}

func TestMigrationContextNoDeadline(t *testing.T) {
	// Zero disables the deadline entirely (for one-off heavy migrations).
	t.Setenv("SILO_MIGRATE_TIMEOUT", "0")
	ctx, cancel := MigrationContext(context.Background())
	defer cancel()
	if deadline, ok := ctx.Deadline(); ok {
		t.Fatalf("expected no deadline with timeout 0, got %v", deadline)
	}
}