package postgres

import (
	"context"
	"errors"
	"fmt"
	"time"

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

	"telesrv/internal/domain"
	"telesrv/internal/store/postgres/sqlcgen"
)

type AdminStore struct {
	db sqlcgen.DBTX
}

func NewAdminStore(db sqlcgen.DBTX) *AdminStore {
	return &AdminStore{db: db}
}

func (s *AdminStore) BeginCommand(ctx context.Context, cmd domain.AdminCommand) (domain.AdminCommand, bool, error) {
	inserted, err := scanAdminCommand(s.db.QueryRow(ctx, `
INSERT INTO admin_commands (
	command_id, actor, action, target_user_id, target_peer_type, target_peer_id,
	dry_run, reason, request, result, status, error, created_at
) VALUES (
	$1,$2,$3,$4,$5,$6,$7,$8,$9::jsonb,'{}'::jsonb,$10,'',$11
)
ON CONFLICT (command_id) DO NOTHING
RETURNING command_id, actor, action, target_user_id, target_peer_type, target_peer_id,
	dry_run, reason, request, result, status, error, created_at, completed_at`,
		cmd.CommandID, cmd.Actor, cmd.Action, cmd.TargetUserID, string(cmd.TargetPeer.Type), cmd.TargetPeer.ID,
		cmd.DryRun, cmd.Reason, string(cmd.RequestJSON), string(cmd.Status), cmd.CreatedAt,
	))
	if err == nil {
		return inserted, true, nil
	}
	if !errors.Is(err, pgx.ErrNoRows) {
		return domain.AdminCommand{}, false, fmt.Errorf("insert admin command: %w", err)
	}
	existing, err := s.commandByID(ctx, cmd.CommandID)
	if err != nil {
		return domain.AdminCommand{}, false, err
	}
	return existing, false, nil
}

func (s *AdminStore) FinishCommand(ctx context.Context, commandID string, status domain.AdminCommandStatus, resultJSON []byte, errorText string) (domain.AdminCommand, error) {
	if len(resultJSON) == 0 {
		resultJSON = []byte("{}")
	}
	beginner, ok := s.db.(txBeginner)
	if !ok {
		return s.finishCommandNoTx(ctx, commandID, status, resultJSON, errorText)
	}
	tx, err := beginner.Begin(ctx)
	if err != nil {
		return domain.AdminCommand{}, fmt.Errorf("begin finish admin command tx: %w", err)
	}
	committed := false
	defer func() {
		if !committed {
			_ = tx.Rollback(ctx)
		}
	}()
	cmd, err := finishAdminCommand(ctx, tx, commandID, status, resultJSON, errorText)
	if err != nil {
		return domain.AdminCommand{}, err
	}
	if err := appendAdminAuditLog(ctx, tx, commandID); err != nil {
		return domain.AdminCommand{}, err
	}
	if err := tx.Commit(ctx); err != nil {
		return domain.AdminCommand{}, fmt.Errorf("commit finish admin command tx: %w", err)
	}
	committed = true
	return cmd, nil
}

func (s *AdminStore) finishCommandNoTx(ctx context.Context, commandID string, status domain.AdminCommandStatus, resultJSON []byte, errorText string) (domain.AdminCommand, error) {
	cmd, err := finishAdminCommand(ctx, s.db, commandID, status, resultJSON, errorText)
	if err != nil {
		return domain.AdminCommand{}, err
	}
	if err := appendAdminAuditLog(ctx, s.db, commandID); err != nil {
		return domain.AdminCommand{}, err
	}
	return cmd, nil
}

func finishAdminCommand(ctx context.Context, db sqlcgen.DBTX, commandID string, status domain.AdminCommandStatus, resultJSON []byte, errorText string) (domain.AdminCommand, error) {
	cmd, err := scanAdminCommand(db.QueryRow(ctx, `
UPDATE admin_commands
SET status = $2, result = $3::jsonb, error = $4, completed_at = now()
WHERE command_id = $1
RETURNING command_id, actor, action, target_user_id, target_peer_type, target_peer_id,
	dry_run, reason, request, result, status, error, created_at, completed_at`,
		commandID, string(status), string(resultJSON), errorText,
	))
	if err != nil {
		return domain.AdminCommand{}, fmt.Errorf("finish admin command: %w", err)
	}
	return cmd, nil
}

func appendAdminAuditLog(ctx context.Context, db sqlcgen.DBTX, commandID string) error {
	if _, err := db.Exec(ctx, `
INSERT INTO admin_audit_logs (
	command_id, actor, action, target_user_id, target_peer_type, target_peer_id,
	dry_run, reason, request, result, status, error, created_at
)
SELECT command_id, actor, action, target_user_id, target_peer_type, target_peer_id,
	dry_run, reason, request, result, status, error, now()
FROM admin_commands
WHERE command_id = $1
ON CONFLICT (command_id) DO NOTHING`, commandID); err != nil {
		return fmt.Errorf("append admin audit log: %w", err)
	}
	return nil
}

func (s *AdminStore) commandByID(ctx context.Context, commandID string) (domain.AdminCommand, error) {
	cmd, err := scanAdminCommand(s.db.QueryRow(ctx, `
SELECT command_id, actor, action, target_user_id, target_peer_type, target_peer_id,
	dry_run, reason, request, result, status, error, created_at, completed_at
FROM admin_commands
WHERE command_id = $1`, commandID))
	if err != nil {
		return domain.AdminCommand{}, fmt.Errorf("get admin command: %w", err)
	}
	return cmd, nil
}

func scanAdminCommand(row pgx.Row) (domain.AdminCommand, error) {
	var cmd domain.AdminCommand
	var peerType string
	var status string
	var completed pgtype.Timestamptz
	if err := row.Scan(
		&cmd.CommandID,
		&cmd.Actor,
		&cmd.Action,
		&cmd.TargetUserID,
		&peerType,
		&cmd.TargetPeer.ID,
		&cmd.DryRun,
		&cmd.Reason,
		&cmd.RequestJSON,
		&cmd.ResultJSON,
		&status,
		&cmd.Error,
		&cmd.CreatedAt,
		&completed,
	); err != nil {
		return domain.AdminCommand{}, err
	}
	cmd.TargetPeer.Type = domain.PeerType(peerType)
	cmd.Status = domain.AdminCommandStatus(status)
	if completed.Valid {
		t := completed.Time
		cmd.CompletedAt = &t
	}
	return cmd, nil
}

func (s *AdminStore) GetSendRestriction(ctx context.Context, userID int64) (domain.AccountSendRestriction, bool, error) {
	row := s.db.QueryRow(ctx, `
SELECT user_id, frozen, reason, actor, command_id, updated_at
FROM account_send_restrictions
WHERE user_id = $1`, userID)
	r, err := scanSendRestriction(row)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return domain.AccountSendRestriction{}, false, nil
		}
		return domain.AccountSendRestriction{}, false, fmt.Errorf("get send restriction: %w", err)
	}
	return r, true, nil
}

func (s *AdminStore) SetSendRestriction(ctx context.Context, restriction domain.AccountSendRestriction) (domain.AccountSendRestriction, error) {
	row := s.db.QueryRow(ctx, `
INSERT INTO account_send_restrictions (user_id, frozen, reason, actor, command_id, updated_at)
VALUES ($1,$2,$3,$4,$5,now())
ON CONFLICT (user_id) DO UPDATE SET
	frozen = EXCLUDED.frozen,
	reason = EXCLUDED.reason,
	actor = EXCLUDED.actor,
	command_id = EXCLUDED.command_id,
	updated_at = now()
RETURNING user_id, frozen, reason, actor, command_id, updated_at`,
		restriction.UserID, restriction.Frozen, restriction.Reason, restriction.Actor, restriction.CommandID,
	)
	out, err := scanSendRestriction(row)
	if err != nil {
		return domain.AccountSendRestriction{}, fmt.Errorf("set send restriction: %w", err)
	}
	return out, nil
}

func (s *AdminStore) IsSendFrozen(ctx context.Context, userID int64) (bool, error) {
	var frozen bool
	if err := s.db.QueryRow(ctx, `SELECT frozen FROM account_send_restrictions WHERE user_id = $1`, userID).Scan(&frozen); err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return false, nil
		}
		return false, fmt.Errorf("check send restriction: %w", err)
	}
	return frozen, nil
}

func scanSendRestriction(row pgx.Row) (domain.AccountSendRestriction, error) {
	var r domain.AccountSendRestriction
	var updated time.Time
	if err := row.Scan(&r.UserID, &r.Frozen, &r.Reason, &r.Actor, &r.CommandID, &updated); err != nil {
		return domain.AccountSendRestriction{}, err
	}
	r.UpdatedAt = updated
	return r, nil
}