// Package tests contains the per-stage executors the agent runs on the
// host under test. Each stage implements Runner, is called with a
// Context that carries the client + forwarder + run params, and returns
// an Outcome that the caller POSTs to /result.
package tests

import (
	"context"
	"encoding/json"
	"time"
)

// Outcome is what a stage returns; it maps directly to the /result body.
//   - Passed=true and len(Skipped)>0 counts as a pass but surfaces in the
//     tile summary so operators can see "GPU: skipped (no VGA device)".
//   - Message is only used on failure; the UI displays it in the log.
//   - Extras is merged into the posted summary so stages can add
//     their own shape (e.g. Storage returns per-disk probe results).
//   - SubSteps carries agent-authored sub-step rows (CPU/Memory passes,
//     per-disk SMART, per-device GPU, …). Empty for stages with no
//     natural breakdown; persisted verbatim by the /result handler.
type Outcome struct {
	Passed   bool
	Message  string
	Summary  string           // short human-readable one-liner
	Extras   map[string]any   // merged into posted summary JSON
	SubSteps []SubStepReport  // agent-authored granular rows
}

// SubStepReport is one entry a stage contributes to its sub-step list.
// Ordinal is assigned in the order entries appear in the slice — the
// agent shouldn't set it manually. State is derived from Passed/Skipped
// the same way Outcome is: Skipped wins if set, else Passed ? passed :
// failed. StartedAt/CompletedAt are required so the UI can order rows
// and slice the stage log by time window.
type SubStepReport struct {
	Name        string
	Passed      bool
	Skipped     bool
	StartedAt   time.Time
	CompletedAt time.Time
	SummaryJSON json.RawMessage
}

// MarshalSummary builds the summary JSON body POSTed to /result.
// Stages accumulate fields via Extras; this helper adds "summary" (the
// human-readable line) and serializes.
func (o Outcome) MarshalSummary() (json.RawMessage, error) {
	body := map[string]any{}
	for k, v := range o.Extras {
		body[k] = v
	}
	if o.Summary != "" {
		body["summary"] = o.Summary
	}
	return json.Marshal(body)
}

// Deps bundles what stages need without pulling in the whole agent.
// Logger methods print to stdout + forward to the orchestrator; Sensor
// drops numeric samples; OverrideFlags carries operator-set bypasses.
//
// CPUStressKnobs / StorageKnobs / NetworkKnobs are Phase-2 profile
// knobs. Zero-valued fields mean "fall back to the compile-time
// default" — that keeps the stages runnable even when the runner can't
// materialize a profile (tests, legacy orchestrator, etc).
type Deps struct {
	Info           func(string)
	Warn           func(string)
	Error          func(string)
	Sensor         func(ctx context.Context, samples []Sample) error
	OverrideWipe   bool
	NonDestructive bool           // skip wipe-probe + writes in Storage
	ExpectedDisks  []ExpectedDisk // serials + sizes from host.expected_spec
	StageTimeout   time.Duration
	CPUStressKnobs CPUStressKnobs
	StorageKnobs   StorageKnobs
	NetworkKnobs   NetworkKnobs
	BurnKnobs      BurnKnobs
	// LookPath is the unit-test seam for swapping a real external
	// binary (stress-ng, fio, iperf3, dmidecode, …) for a fake. When
	// nil the stage falls back to os/exec.LookPath — production and
	// existing tests keep working unchanged. Tests under
	// agent/tests/fakes/ populate this to redirect lookups to a built
	// fake binary in a tempdir.
	LookPath func(name string) (string, error)
}

// CPUStressKnobs parameterizes the CPUStress stage. Zero durations fall
// back to the package's compile-time defaults (cpuPassDuration etc).
type CPUStressKnobs struct {
	CPUPass  time.Duration
	MemPass  time.Duration
	EDACPoll time.Duration
}

// StorageKnobs parameterizes the Storage stage. Mode picks between
// "fio_sample" (bounded tempfile inside the device, quick profile) and
// "full_disk" (whole-device write verify, deep/soak). Empty strings
// fall back to the stage's safe defaults.
type StorageKnobs struct {
	Mode    string
	FioSize string
	FioTime time.Duration
	FioBS   string
	FioRW   string
	Verify  string
}

// NetworkKnobs parameterizes the Network stage.
type NetworkKnobs struct {
	Duration time.Duration
}

// BurnKnobs parameterizes the Burn super-stage. Duration is the total
// Burn window; sub-workloads run concurrently inside that window.
// CPUWorkers is "all" (runtime.NumCPU) or a numeric string. MemPct is a
// percentage of MemAvailable to allocate for the memory burner (clamped
// 0-90 by the stage). IperfParallel feeds iperf3 -P to generate sustained
// NIC load. FioOnSpare gates the storage sub-workload: true = fio runs
// against the allow-listed disks for the same window; false = skip fio.
type BurnKnobs struct {
	Duration      time.Duration
	CPUWorkers    string
	MemPct        int
	FioOnSpare    bool
	IperfParallel int
}

// Sample mirrors the server's SensorSample but lives in the tests
// package so probe code doesn't import internal/api.
type Sample struct {
	Kind  string
	Key   string
	Value float64
	Unit  string
}

// ExpectedDisk is the subset of internal/spec.DiskSpec that Storage
// needs: a device allowlist keyed on serial.
type ExpectedDisk struct {
	Serial string
	SizeGB int
}