package domain

import "time"

// ExecutionObserver receives one immutable metadata event synchronously.
type ExecutionObserver func(ExecutionEvent)

type ExecutionEventKind string

const (
	ExecutionStarted    ExecutionEventKind = "started"
	ExecutionAttempt    ExecutionEventKind = "attempt"
	ExecutionRetryDelay ExecutionEventKind = "retry_delay"
	ExecutionFinished   ExecutionEventKind = "finished"
)

type ExecutionOutcome string

const (
	ExecutionOutcomeSuccess       ExecutionOutcome = "success"
	ExecutionOutcomeInvalidOutput ExecutionOutcome = "invalid_output"
	ExecutionOutcomeError         ExecutionOutcome = "error"
)

type ExecutionFailureKind string

const (
	ExecutionFailureNone              ExecutionFailureKind = ""
	ExecutionFailureCanceled          ExecutionFailureKind = "canceled"
	ExecutionFailureDeadline          ExecutionFailureKind = "deadline"
	ExecutionFailureTransport         ExecutionFailureKind = "transport"
	ExecutionFailureProviderStatus    ExecutionFailureKind = "provider_status"
	ExecutionFailureMalformedResponse ExecutionFailureKind = "malformed_response"
	ExecutionFailureCapacity          ExecutionFailureKind = "capacity"
	ExecutionFailureInvalidConfig     ExecutionFailureKind = "invalid_config"
	ExecutionFailureInvalidRequest    ExecutionFailureKind = "invalid_request"
	ExecutionFailurePromptNotFound    ExecutionFailureKind = "prompt_not_found"
	ExecutionFailureProfileNotFound   ExecutionFailureKind = "profile_not_found"
	ExecutionFailurePromptLoad        ExecutionFailureKind = "prompt_load"
	ExecutionFailureProfileLoad       ExecutionFailureKind = "profile_load"
	ExecutionFailureArtifactLoad      ExecutionFailureKind = "artifact_load"
	ExecutionFailurePromptRender      ExecutionFailureKind = "prompt_render"
	ExecutionFailureValidation        ExecutionFailureKind = "validation"
	ExecutionFailureGeneration        ExecutionFailureKind = "generation"
	ExecutionFailureOther             ExecutionFailureKind = "other"
)

// ObservedTokenCount distinguishes omitted usage from reported zero.
type ObservedTokenCount struct {
	Value    int
	Known    bool
	Complete bool
}

// ObservedTokenUsage reports presence-aware token counts.
type ObservedTokenUsage struct {
	PromptTokens     ObservedTokenCount
	CompletionTokens ObservedTokenCount
	TotalTokens      ObservedTokenCount
	CachedTokens     ObservedTokenCount
	CacheWriteTokens ObservedTokenCount
}

// ExecutionEvent contains metadata only; it carries no mutable containers or
// error values. Nonterminal events leave aggregate counters at zero.
type ExecutionEvent struct {
	Kind               ExecutionEventKind
	RunID              string
	Time               time.Time
	PromptID           string
	PromptVersion      *string
	ProfileID          string
	BackendID          string
	Model              string
	Generation         uint64
	Attempt            uint64
	Dispatched         bool
	CapacityWait       time.Duration
	GenerationDuration time.Duration
	RetryDelay         time.Duration
	Duration           time.Duration
	Outcome            ExecutionOutcome
	Failure            ExecutionFailureKind
	StatusCode         int
	RetriesExhausted   bool
	Usage              ObservedTokenUsage
	Attempts           uint64
	TransientRetries   uint64
	RepairCalls        uint64
}