cutover

type Action struct {
	Kind  string `json:"kind"`
	Label string `json:"label"`
	API   string `json:"api,omitempty"`
	Value string `json:"value,omitempty"`
}

type Check struct {
	ID     string `json:"id"`
	Title  string `json:"title"`
	Status string `json:"status"`
	Detail string `json:"detail,omitempty"`
	Fix    *Fix   `json:"fix,omitempty"`
}

type Config struct {
	HealthTimeout  time.Duration
	ProbeTimeout   time.Duration
	ProbeInterval  time.Duration
	VerifyTimeout  time.Duration
	VerifyInterval time.Duration
	// ResumeMaxAge is how old an interrupted run may be and still be resumed
	// forward after a restart. Older ones are rolled back instead.
	ResumeMaxAge time.Duration
}

type DBFact struct {
	Name string
	Host string
	// Target is the database here the data was moved to, "" when none.
	Target string
	// Verified is true when a recorded copy compared row counts.
	Verified   bool
	Checked    int
	Mismatched int
	// External is true when the database lives outside the source platform
	// and needs no copy.
	External bool
}

type DBStore struct{ DB RunRows }

type DNS interface {
	Apply(ctx context.Context, domain string) (DNSResult, error)
	Restore(ctx context.Context, domain string, previous []Record, applied *Record) error
}

type DNSResult struct {
	Applied  *Record
	Previous []Record
	Provider string
	Zone     string
	Message  string
}

type Deps struct {
	Planner  Planner
	Host     Host
	Ingress  Ingress
	DNS      DNS
	Proxy    Proxy
	Verifier Verifier
}

type DomainFact struct {
	Domain string
	// Current is what the domain resolves to now (addresses or CNAME).
	Current []string
	// PointsHere is true when it already resolves to this server.
	PointsHere bool
	// TakenBy is another app already holding the domain.
	TakenBy string
	Plan    DomainPlan
}

type DomainPlan struct {
	Domain string `json:"domain"`
	Method string `json:"method"`
	// Current is what the domain resolves to or the zone holds now.
	Current  []string `json:"current,omitempty"`
	Provider string   `json:"provider,omitempty"`
	Zone     string   `json:"zone,omitempty"`
	Desired  *Record  `json:"desired,omitempty"`
	// Replace lists the provider records a DNS switch removes first.
	Replace []Record `json:"replace,omitempty"`
	Message string   `json:"message,omitempty"`
}

type DomainRun struct {
	Domain string `json:"domain"`
	Method string `json:"method"`
	// Previous is what rollback restores, written before the switch.
	Previous []Record `json:"previous,omitempty"`
	Applied  *Record  `json:"applied,omitempty"`
	Provider string   `json:"provider,omitempty"`
	Zone     string   `json:"zone,omitempty"`
	// Manual is the exact record to set by hand.
	Manual       *Record `json:"manual,omitempty"`
	ProbeStatus  int     `json:"probe_status,omitempty"`
	ProbeDetail  string  `json:"probe_detail,omitempty"`
	Switched     bool    `json:"switched"`
	Restored     bool    `json:"restored"`
	Verified     bool    `json:"verified"`
	VerifyDetail string  `json:"verify_detail,omitempty"`
	Message      string  `json:"message,omitempty"`
}

type Facts struct {
	App       string
	ItemState string

	ImageSource   string
	Image         string
	ImageVerified bool
	ImageDetail   string

	EnvPlain, EnvSecret, EnvEmptySecrets int

	Databases []DBFact
	Volumes   []VolumeFact

	HealthPath  string
	HealthKnown bool

	Domains []DomainFact
	Now     time.Time
}

type Fix struct {
	Summary string  `json:"summary"`
	Action  *Action `json:"action,omitempty"`
}

type Host interface {
	// Route attaches the domains to the app here and starts it.
	Route(ctx context.Context, app string, domains []string) error
	// Unroute detaches the domains and stops the app again.
	Unroute(ctx context.Context, app string, domains []string) error
	// WaitHealthy returns false with a reason when the app is not ready in time.
	WaitHealthy(ctx context.Context, app string, timeout time.Duration) (ok bool, detail string, err error)
}

type Ingress interface {
	Probe(ctx context.Context, domain, path string) (ProbeResult, error)
}

type Plan struct {
	App       string       `json:"app"`
	SessionID string       `json:"session_id,omitempty"`
	SourceID  string       `json:"source_id,omitempty"`
	Verdict   string       `json:"verdict"`
	Checks    []Check      `json:"checks"`
	Domains   []DomainPlan `json:"domains"`
	// HealthPath is probed through the ingress, "/" when none is defined.
	HealthPath string `json:"health_path"`
	CheckedAt  string `json:"checked_at"`
}

type PlanRequest struct {
	SessionID string
	SourceID  string
	App       string
	// DNSWrite is whether the caller may change DNS records.
	DNSWrite bool
}

type Planner interface {
	Plan(ctx context.Context, req PlanRequest) (Plan, error)
}

type ProbeResult struct {
	OK     bool
	Status int
	Detail string
}

type Proxy interface {
	WriteRoute(ctx context.Context, domain string) error
	RemoveRoute(ctx context.Context, domain string) error
}

type Record struct {
	Name  string `json:"name"`
	Type  string `json:"type"`
	Value string `json:"value"`
	TTL   int    `json:"ttl_seconds,omitempty"`
}

type Run struct {
	ID         string      `json:"id"`
	SessionID  string      `json:"session_id"`
	SourceID   string      `json:"source_id"`
	App        string      `json:"app"`
	Mode       string      `json:"mode"`
	State      string      `json:"state"`
	Method     string      `json:"method,omitempty"`
	DNSWrite   bool        `json:"dns_write"`
	WasRouted  bool        `json:"was_routed"`
	AcceptWarn bool        `json:"accept_warnings"`
	Awaiting   string      `json:"awaiting,omitempty"`
	Domains    []DomainRun `json:"domains"`
	Steps      []Step      `json:"steps"`
	Plan       *Plan       `json:"plan,omitempty"`
	Error      string      `json:"error,omitempty"`
	CreatedAt  time.Time   `json:"created_at"`
	UpdatedAt  time.Time   `json:"updated_at"`
	FinishedAt time.Time   `json:"finished_at,omitzero"`
}

type RunRows interface {
	CreateCutoverRun(ctx context.Context, r store.CutoverRun) error
	SaveCutoverRun(ctx context.Context, r store.CutoverRun) error
	GetCutoverRun(ctx context.Context, id string) (store.CutoverRun, error)
	ListCutoverRuns(ctx context.Context, app string, limit int) ([]store.CutoverRun, error)
	ListCutoverRunsByState(ctx context.Context, states ...string) ([]store.CutoverRun, error)
}

type Runner struct {
	Store Store
	Deps  Deps
	Cfg   Config
	Log   *slog.Logger
	Now   func() time.Time
	Sleep func(ctx context.Context, d time.Duration) error
	// Hook runs after each persisted step. A non-nil error aborts Execute
	// with no cleanup, which is how tests simulate a process crash.
	Hook func(run Run, step string) error
}

type StartRequest struct {
	SessionID  string
	SourceID   string
	App        string
	Mode       string
	DNSWrite   bool
	WasRouted  bool
	AcceptWarn bool
}

type Step struct {
	Name       string    `json:"name"`
	State      string    `json:"state"`
	Domain     string    `json:"domain,omitempty"`
	Detail     string    `json:"detail,omitempty"`
	StartedAt  time.Time `json:"started_at"`
	FinishedAt time.Time `json:"finished_at,omitzero"`
	DurationMS int64     `json:"duration_ms"`
}

type Store interface {
	Create(ctx context.Context, r Run) error
	Get(ctx context.Context, id string) (Run, error)
	Save(ctx context.Context, r Run) error
	List(ctx context.Context, app string, limit int) ([]Run, error)
	ListByState(ctx context.Context, states ...string) ([]Run, error)
}

type Verifier interface {
	Verify(ctx context.Context, app, domain string) (ok bool, detail string, err error)
}

type VolumeFact struct {
	Name   string
	Path   string
	Copied bool
}