package api

import (
	"encoding/json"
	"time"
)

// HostOS / HostArch are constrained string types. The store stores them
// raw, but agent metadata collection should populate them from these
// constants so we don't end up with both "linux" and "Linux" rows.
type HostOS string

const (
	OSLinux   HostOS = "linux"
	OSWindows HostOS = "windows"
)

type HostArch string

const (
	ArchAmd64 HostArch = "amd64"
	ArchArm64 HostArch = "arm64"
)

// HelloPayload is the agent's first message after WS auth. The server
// upserts a Host row, marks it online, and (if protocol_version is
// acceptable) responds with a config.update + schedule.set burst.
type HelloPayload struct {
	ProtocolVersion int       `json:"protocol_version"`
	AgentVersion    string    `json:"agent_version"`
	ResticVersion   string    `json:"restic_version"`
	Hostname        string    `json:"hostname"`
	OS              HostOS    `json:"os"`
	Arch            HostArch  `json:"arch"`
	BootTime        time.Time `json:"boot_time,omitempty"`
}

// HeartbeatPayload is sent by the agent every 30s. It carries no data
// today; presence is the signal. Future fields (load, free disk) can
// land here without bumping protocol_version.
type HeartbeatPayload struct {
	SentAt time.Time `json:"sent_at"`
}

// JobKind is the operation an agent is being asked to run, or just ran.
type JobKind string

const (
	JobBackup JobKind = "backup"
	JobInit   JobKind = "init"
	JobForget JobKind = "forget"
	JobPrune  JobKind = "prune"
	JobCheck  JobKind = "check"
	JobUnlock JobKind = "unlock"
)

// JobStatus is the lifecycle state of a job.
type JobStatus string

const (
	JobQueued    JobStatus = "queued"
	JobRunning   JobStatus = "running"
	JobSucceeded JobStatus = "succeeded"
	JobFailed    JobStatus = "failed"
	JobCancelled JobStatus = "cancelled"
)

// CommandRunPayload is the server → agent dispatch for a run-now job.
//
// For kind=backup, Includes/Excludes/Tag are populated from the source
// group the operator (or schedule) targeted; the agent runs one restic
// backup invocation per command.run, tagging the snapshot with Tag (=
// the source group's name) so retention can target it later via
// `restic forget --tag`.
//
// For kind=forget, RetentionPolicy is the typed keep-* set as raw JSON
// (the agent doesn't share the store package's typed struct).
//
// Args is preserved as a generic free-form slice for kinds that don't
// fit the structured fields (e.g. unlock takes none; init takes none).
type CommandRunPayload struct {
	JobID           string          `json:"job_id"`
	Kind            JobKind         `json:"kind"`
	Args            []string        `json:"args,omitempty"`
	Includes        []string        `json:"includes,omitempty"`
	Excludes        []string        `json:"excludes,omitempty"`
	Tag             string          `json:"tag,omitempty"`
	RetentionPolicy json.RawMessage `json:"retention_policy,omitempty"`
}

// CommandCancelPayload is the server → agent cancel signal.
type CommandCancelPayload struct {
	JobID string `json:"job_id"`
}

// CommandResultPayload acks a command.run dispatch (the agent has
// accepted the job and persisted it locally) — this is *not* the job
// completion. job.finished signals that.
type CommandResultPayload struct {
	JobID    string `json:"job_id"`
	Accepted bool   `json:"accepted"`
	Error    string `json:"error,omitempty"`
}

// JobStartedPayload — agent has begun execution.
type JobStartedPayload struct {
	JobID     string    `json:"job_id"`
	Kind      JobKind   `json:"kind"`
	StartedAt time.Time `json:"started_at"`
}

// JobProgressPayload — agent's periodic status while a job is running.
// Field set chosen to match what restic --json emits for `backup`;
// other kinds populate the subset that makes sense.
type JobProgressPayload struct {
	JobID         string  `json:"job_id"`
	PercentDone   float64 `json:"percent_done"`
	FilesDone     int64   `json:"files_done"`
	TotalFiles    int64   `json:"total_files"`
	BytesDone     int64   `json:"bytes_done"`
	TotalBytes    int64   `json:"total_bytes"`
	ETASeconds    int64   `json:"eta_seconds"`
	ThroughputBps int64   `json:"throughput_bps"`
}

// JobFinishedPayload — agent reports terminal state.
type JobFinishedPayload struct {
	JobID      string          `json:"job_id"`
	Status     JobStatus       `json:"status"`
	ExitCode   int             `json:"exit_code"`
	FinishedAt time.Time       `json:"finished_at"`
	Stats      json.RawMessage `json:"stats,omitempty"` // restic summary blob
	Error      string          `json:"error,omitempty"`
}

// LogStreamLine is one entry of the live job log.
type LogStreamLine struct {
	JobID   string    `json:"job_id"`
	Seq     int64     `json:"seq"`
	TS      time.Time `json:"ts"`
	Stream  LogStream `json:"stream"`
	Payload string    `json:"payload"`
}

// LogStream identifies which channel a log line came from.
type LogStream string

const (
	LogStdout LogStream = "stdout"
	LogStderr LogStream = "stderr"
	LogEvent  LogStream = "event" // parsed restic --json event
)

// SnapshotsReportPayload — agent dumps its full snapshot list after
// each successful backup, so the server can refresh its projection.
type SnapshotsReportPayload struct {
	Snapshots []Snapshot `json:"snapshots"`
}

// Snapshot is the projection mirrored from `restic snapshots --json`.
// SizeBytes / FileCount come from the embedded summary block on
// restic 0.16+; older clients leave them at zero (the UI degrades
// gracefully).
type Snapshot struct {
	ID        string    `json:"id"`       // long restic snapshot ID
	ShortID   string    `json:"short_id"` // 8-hex-char form
	Time      time.Time `json:"time"`
	Hostname  string    `json:"hostname"`
	Paths     []string  `json:"paths"`
	Tags      []string  `json:"tags,omitempty"`
	SizeBytes int64     `json:"size_bytes,omitempty"`
	FileCount int64     `json:"file_count,omitempty"`
}

// RepoStatsPayload — agent reports periodic repo health facts derived
// from `restic stats` and lock-file inspection.
type RepoStatsPayload struct {
	SizeBytes        int64     `json:"size_bytes"`
	SnapshotCount    int       `json:"snapshot_count"`
	DedupRatio       float64   `json:"dedup_ratio"`
	LastCheckAt      time.Time `json:"last_check_at,omitempty"`
	LastCheckStatus  string    `json:"last_check_status,omitempty"`
	LockState        string    `json:"lock_state"` // locked|unlocked
}

// Schedule is the agent-facing view of a slim Schedule row plus its
// resolved bundle of source groups. The agent's cron only needs to know
// when to fire (CronExpr + Enabled) and which schedule fired (ID); the
// SourceGroups are carried for forensic logs and so a future agent that
// elects to dispatch jobs locally has the data, but the server-side
// dispatch path uses the schedule's group list directly. Manual
// schedules are gone — Run-now targets a source group, not a schedule.
type Schedule struct {
	ID           string                `json:"id"`
	CronExpr     string                `json:"cron_expr"`
	Enabled      bool                  `json:"enabled"`
	SourceGroups []ScheduleSourceGroup `json:"source_groups,omitempty"`
}

// ScheduleSourceGroup is the resolved-at-push-time view of a source
// group attached to a schedule. The agent doesn't need source_group_id
// — Name is the snapshot tag and is unique per host.
type ScheduleSourceGroup struct {
	Name                string          `json:"name"`
	Includes            []string        `json:"includes,omitempty"`
	Excludes            []string        `json:"excludes,omitempty"`
	RetentionPolicy     json.RawMessage `json:"retention_policy,omitempty"`
	RetryMax            int             `json:"retry_max,omitempty"`
	RetryBackoffSeconds int             `json:"retry_backoff_seconds,omitempty"`
}

// ScheduleSetPayload — server pushes the full canonical schedule list
// for a host. Agent reconciles its local cron and replies with
// ScheduleAckPayload carrying the same Version. An empty Schedules
// list is a valid push that disables every cron entry.
type ScheduleSetPayload struct {
	Version   int64      `json:"version"`
	Schedules []Schedule `json:"schedules"`
}

// ScheduleAckPayload — agent confirms it has applied a given version.
type ScheduleAckPayload struct {
	Version    int64     `json:"version"`
	AppliedAt  time.Time `json:"applied_at"`
}

// ScheduleFirePayload — agent reports a local cron entry just fired.
// Server is expected to look up the schedule, build a CommandRun
// payload from it, persist a job row, and return MsgCommandRun on
// the same connection. ScheduledAt is the wall-clock time the
// agent's cron fired (audit / forensic value when network jitter
// pushes the actual command.run dispatch later).
type ScheduleFirePayload struct {
	ScheduleID  string    `json:"schedule_id"`
	ScheduledAt time.Time `json:"scheduled_at"`
}

// ConfigUpdatePayload — server pushes per-host config (currently just
// repo connection details). Empty fields mean "leave existing alone";
// to clear something, send an explicit zero value.
type ConfigUpdatePayload struct {
	RepoURL          string `json:"repo_url,omitempty"`
	RepoPassword     string `json:"repo_password,omitempty"` // sensitive
	RepoUsername     string `json:"repo_username,omitempty"`
	RepoCredential   string `json:"repo_credential,omitempty"` // sensitive (for rest server basic auth)
	HookShell        string `json:"hook_shell,omitempty"`
}

// AgentUpdateAvailablePayload — informational only; the agent does
// NOT self-update. See spec.md §4.2 for the package-manager-based
// update model.
type AgentUpdateAvailablePayload struct {
	LatestVersion string `json:"latest_version"`
	PackageURL    string `json:"package_url"` // apt repo / choco source
	Changelog     string `json:"changelog,omitempty"`
}