package db

import (
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"time"
)

// Oath action types — immutable accountability rows.
const (
	OathSpreadTierEscalation = "spread_tier_escalation"
	OathGraft                = "graft"
	OathForkMerge            = "fork_merge"
	OathStrainCardPlay       = "strain_card_play"
	OathCourtL4Decision      = "court_l4_decision"
	OathSpreadAttempt        = "spread_attempt"
	OathSpreadDiscoveredHost = "spread_discovered_host"
	OathStrainHospice        = "strain_hospice"
	OathReconScan            = "recon_scan"
)

// Oath outcomes.
const (
	OathOutcomeSuccess = "success"
	OathOutcomeFail    = "fail"
	OathOutcomePending = "pending"
)

// OathLedgerEntry is one immutable operator / AI council accountability row.
type OathLedgerEntry struct {
	ID          int64           `json:"id"`
	Timestamp   string          `json:"timestamp"`
	Actor       string          `json:"actor"`
	ActionType  string          `json:"action_type"`
	AgentID     string          `json:"agent_id"`
	Strain      string          `json:"strain"`
	WhyHash     string          `json:"why_hash"`
	Outcome     string          `json:"outcome"`
	PayloadJSON json.RawMessage `json:"payload_json"`
}

func (d *Database) ensureOathLedgerTable() error {
	_, err := d.Exec(`CREATE TABLE IF NOT EXISTS oath_ledger (
		id INTEGER PRIMARY KEY AUTOINCREMENT,
		timestamp DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
		actor TEXT NOT NULL DEFAULT '',
		action_type TEXT NOT NULL,
		agent_id TEXT NOT NULL DEFAULT '',
		strain TEXT NOT NULL DEFAULT '',
		why_hash TEXT NOT NULL DEFAULT '',
		outcome TEXT NOT NULL DEFAULT 'pending',
		payload_json TEXT NOT NULL DEFAULT '{}'
	)`)
	if err != nil {
		return err
	}
	_, _ = d.Exec(`CREATE INDEX IF NOT EXISTS idx_oath_ledger_ts ON oath_ledger(timestamp)`)
	_, _ = d.Exec(`CREATE INDEX IF NOT EXISTS idx_oath_ledger_action ON oath_ledger(action_type)`)
	return nil
}

// HashWhyJSON returns SHA256 hex of JSON-encoded source evidence (autopsy / court transcript).
func HashWhyJSON(source interface{}) string {
	if source == nil {
		return ""
	}
	raw, err := json.Marshal(source)
	if err != nil {
		raw = []byte("{}")
	}
	sum := sha256.Sum256(raw)
	return hex.EncodeToString(sum[:])
}

func marshalOathPayload(payload interface{}) []byte {
	if payload == nil {
		return []byte("{}")
	}
	switch v := payload.(type) {
	case json.RawMessage:
		if len(v) == 0 {
			return []byte("{}")
		}
		return v
	case map[string]interface{}:
		raw, err := json.Marshal(v)
		if err != nil {
			return []byte("{}")
		}
		return raw
	default:
		raw, err := json.Marshal(payload)
		if err != nil {
			return []byte("{}")
		}
		return raw
	}
}

// InsertOathLedger appends one immutable accountability row.
func (d *Database) InsertOathLedger(actor, actionType, agentID, strain, whyHash, outcome string, payload interface{}) (*OathLedgerEntry, error) {
	if d == nil {
		return nil, nil
	}
	if err := d.ensureOathLedgerTable(); err != nil {
		return nil, err
	}
	if outcome == "" {
		outcome = OathOutcomePending
	}
	payloadJSON := marshalOathPayload(payload)
	ts := time.Now().UTC()
	res, err := d.Exec(
		`INSERT INTO oath_ledger (timestamp, actor, action_type, agent_id, strain, why_hash, outcome, payload_json)
		 VALUES (?, ?, ?, ?, ?, ?, ?, ?)`,
		ts, actor, actionType, agentID, strain, whyHash, outcome, string(payloadJSON),
	)
	if err != nil {
		return nil, err
	}
	id, _ := res.LastInsertId()
	return &OathLedgerEntry{
		ID:          id,
		Timestamp:   ts.Format(time.RFC3339),
		Actor:       actor,
		ActionType:  actionType,
		AgentID:     agentID,
		Strain:      strain,
		WhyHash:     whyHash,
		Outcome:     outcome,
		PayloadJSON: json.RawMessage(payloadJSON),
	}, nil
}

// ListOathLedger returns recent rows newest-first.
func (d *Database) ListOathLedger(limit int) ([]OathLedgerEntry, error) {
	if d == nil {
		return nil, nil
	}
	if err := d.ensureOathLedgerTable(); err != nil {
		return nil, err
	}
	if limit <= 0 {
		limit = 100
	}
	if limit > 500 {
		limit = 500
	}
	rows, err := d.Query(
		`SELECT id, timestamp, actor, action_type, agent_id, strain, why_hash, outcome, payload_json
		 FROM oath_ledger ORDER BY id DESC LIMIT ?`,
		limit,
	)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []OathLedgerEntry
	for rows.Next() {
		var e OathLedgerEntry
		var ts time.Time
		var payloadStr string
		if err := rows.Scan(&e.ID, &ts, &e.Actor, &e.ActionType, &e.AgentID, &e.Strain, &e.WhyHash, &e.Outcome, &payloadStr); err != nil {
			return nil, err
		}
		e.Timestamp = ts.UTC().Format(time.RFC3339)
		if payloadStr != "" {
			e.PayloadJSON = json.RawMessage(payloadStr)
		}
		out = append(out, e)
	}
	return out, rows.Err()
}