package adminstore

import (
	"context"
	"errors"
	"strings"
	"time"

	"github.com/jackc/pgx/v5/pgconn"

	"github.com/baicai2026-baicai/goods/api/internal/apikey"
)

// APIKeyRow is an admin-facing view of an issued API key (never the secret).
type APIKeyRow struct {
	ID              string  `json:"id"`
	Name            string  `json:"name"`
	KeyPrefix       string  `json:"key_prefix"`
	OwnerEmail      *string `json:"owner_email"`
	Tier            string  `json:"tier"`
	RateLimitPerMin int     `json:"rate_limit_per_min"`
	QuotaTotal      int64   `json:"quota_total"`
	RevokedAt       *string `json:"revoked_at"`
	CreatedBy       *string `json:"created_by"`
	CreatedAt       string  `json:"created_at"`
}

// APIKeyInput holds the fields accepted when issuing a key.
type APIKeyInput struct {
	Name            string `json:"name"`
	OwnerEmail      string `json:"owner_email"`
	Tier            string `json:"tier"`
	RateLimitPerMin int    `json:"rate_limit_per_min"`
	QuotaTotal      int64  `json:"quota_total"`
}

// CreateAPIKey issues a new key, returning the one-time plaintext alongside the
// stored row. Only the SHA-256 hash and a short display prefix are persisted.
func (s *Store) CreateAPIKey(ctx context.Context, in APIKeyInput, createdBy string) (plaintext string, row APIKeyRow, err error) {
	tier := in.Tier
	if tier == "" {
		tier = "free"
	}
	rate := in.RateLimitPerMin
	if rate <= 0 {
		rate = 120
	}
	quota := in.QuotaTotal
	if quota < 0 {
		quota = 0
	}
	var owner *string
	if e := strings.TrimSpace(in.OwnerEmail); e != "" {
		owner = &e
	}

	key, hash, prefix, err := apikey.Generate()
	if err != nil {
		return "", row, err
	}

	var revoked, created *time.Time
	var createdByOut *string
	err = s.pool.QueryRow(ctx, `
INSERT INTO api_key (name, key_prefix, key_hash, owner_email, tier, rate_limit_per_min, quota_total, created_by)
VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
RETURNING id, name, key_prefix, owner_email, tier, rate_limit_per_min, quota_total, revoked_at, created_by, created_at`,
		strings.TrimSpace(in.Name), prefix, hash, owner, tier, rate, quota, createdBy,
	).Scan(&row.ID, &row.Name, &row.KeyPrefix, &row.OwnerEmail, &row.Tier,
		&row.RateLimitPerMin, &row.QuotaTotal, &revoked, &createdByOut, &created)
	if err != nil {
		return "", row, err
	}
	row.CreatedBy = createdByOut
	if created != nil {
		row.CreatedAt = created.Format(time.RFC3339)
	}
	return key, row, nil
}

// ListAPIKeys returns all keys (active first, newest first).
func (s *Store) ListAPIKeys(ctx context.Context) ([]APIKeyRow, error) {
	rows, err := s.pool.Query(ctx, `
SELECT id, name, key_prefix, owner_email, tier, rate_limit_per_min, quota_total, revoked_at, created_by, created_at
FROM api_key
ORDER BY (revoked_at IS NULL) DESC, created_at DESC`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := []APIKeyRow{}
	for rows.Next() {
		var r APIKeyRow
		var revoked, created *time.Time
		if err := rows.Scan(&r.ID, &r.Name, &r.KeyPrefix, &r.OwnerEmail, &r.Tier,
			&r.RateLimitPerMin, &r.QuotaTotal, &revoked, &r.CreatedBy, &created); err != nil {
			return nil, err
		}
		if revoked != nil {
			v := revoked.Format(time.RFC3339)
			r.RevokedAt = &v
		}
		if created != nil {
			r.CreatedAt = created.Format(time.RFC3339)
		}
		out = append(out, r)
	}
	return out, rows.Err()
}

// RevokeAPIKey marks a key revoked. Revoking an already-revoked or missing key
// returns ErrNotFound.
func (s *Store) RevokeAPIKey(ctx context.Context, id string) error {
	tag, err := s.pool.Exec(ctx,
		"UPDATE api_key SET revoked_at = now() WHERE id = $1 AND revoked_at IS NULL", id)
	if err != nil {
		if isInvalidUUID(err) {
			return ErrNotFound
		}
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrNotFound
	}
	return nil
}

// isInvalidUUID reports whether err is a Postgres invalid-UUID-text error,
// which happens when a non-UUID id is supplied.
func isInvalidUUID(err error) bool {
	var pgErr *pgconn.PgError
	if errors.As(err, &pgErr) {
		return pgErr.Code == "22P02"
	}
	return false
}