package app

import (
	"context"
	"errors"
	"time"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"

	"github.com/geo-platform/tenant-api/internal/shared/auth"
	"github.com/geo-platform/tenant-api/internal/shared/response"
	"github.com/geo-platform/tenant-api/internal/tenant/repository"
)

type DesktopAccountService struct {
	repo repository.DesktopAccountRepository
}

func NewDesktopAccountService(repo repository.DesktopAccountRepository) *DesktopAccountService {
	return &DesktopAccountService{repo: repo}
}

type DesktopAccountView struct {
	ID                 string     `json:"id"`
	Platform           string     `json:"platform"`
	PlatformUID        string     `json:"platform_uid"`
	DisplayName        string     `json:"display_name"`
	Health             string     `json:"health"`
	ClientID           *string    `json:"client_id"`
	AccountFingerprint *string    `json:"account_fingerprint"`
	VerifiedAt         *time.Time `json:"verified_at"`
	Tags               []string   `json:"tags"`
	SyncVersion        int64      `json:"sync_version"`
	DeletedAt          *time.Time `json:"deleted_at"`
	DeleteRequestedAt  *time.Time `json:"delete_requested_at"`
}

type UpsertDesktopAccountRequest struct {
	Platform           string     `json:"platform" binding:"required"`
	PlatformUID        string     `json:"platform_uid" binding:"required"`
	AccountFingerprint *string    `json:"account_fingerprint"`
	DisplayName        string     `json:"display_name" binding:"required"`
	Health             string     `json:"health" binding:"required,oneof=live expired captcha risk"`
	VerifiedAt         *time.Time `json:"verified_at"`
	Tags               []string   `json:"tags"`
	IfSyncVersion      *int64     `json:"if_sync_version"`
}

type PatchDesktopAccountRequest struct {
	DisplayName   *string    `json:"display_name"`
	Health        *string    `json:"health" binding:"omitempty,oneof=live expired captcha risk"`
	VerifiedAt    *time.Time `json:"verified_at"`
	Tags          *[]string  `json:"tags"`
	IfSyncVersion int64      `json:"if_sync_version" binding:"required"`
}

func (s *DesktopAccountService) ListByClient(ctx context.Context, client *repository.DesktopClient) ([]DesktopAccountView, error) {
	if client == nil {
		return nil, response.ErrUnauthorized(40108, "desktop_client_missing", "desktop client context is required")
	}

	rows, err := s.repo.ListByClient(ctx, client.WorkspaceID, client.ID)
	if err != nil {
		return nil, response.ErrInternal(50081, "desktop_accounts_query_failed", "failed to list desktop accounts")
	}

	items := make([]DesktopAccountView, 0, len(rows))
	for _, item := range rows {
		items = append(items, buildDesktopAccountView(&item))
	}
	return items, nil
}

func (s *DesktopAccountService) Upsert(ctx context.Context, client *repository.DesktopClient, req UpsertDesktopAccountRequest) (*DesktopAccountView, error) {
	if client == nil {
		return nil, response.ErrUnauthorized(40108, "desktop_client_missing", "desktop client context is required")
	}

	if req.IfSyncVersion != nil {
		existing, err := s.repo.GetByIdentity(ctx, client.WorkspaceID, req.Platform, req.PlatformUID)
		if err != nil && !errors.Is(err, pgx.ErrNoRows) {
			return nil, response.ErrInternal(50082, "desktop_account_lookup_failed", "failed to inspect desktop account before upsert")
		}
		if existing == nil || errors.Is(err, pgx.ErrNoRows) {
			return nil, response.ErrConflict(40981, "desktop_account_sync_version_required_existing", "if_sync_version is only valid when account already exists")
		}
	}

	account, err := s.repo.Upsert(ctx, repository.UpsertDesktopAccountParams{
		DesktopID:          uuid.New(),
		TenantID:           client.TenantID,
		WorkspaceID:        client.WorkspaceID,
		UserID:             client.UserID,
		ClientID:           client.ID,
		Platform:           req.Platform,
		PlatformUID:        req.PlatformUID,
		AccountFingerprint: req.AccountFingerprint,
		DisplayName:        req.DisplayName,
		Health:             req.Health,
		VerifiedAt:         req.VerifiedAt,
		Tags:               req.Tags,
		IfSyncVersion:      req.IfSyncVersion,
	})
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, response.ErrConflict(40982, "desktop_account_sync_conflict", "desktop account sync version conflict")
		}
		return nil, response.ErrInternal(50083, "desktop_account_upsert_failed", "failed to upsert desktop account")
	}

	view := buildDesktopAccountView(account)
	return &view, nil
}

func (s *DesktopAccountService) Patch(ctx context.Context, client *repository.DesktopClient, desktopID uuid.UUID, req PatchDesktopAccountRequest) (*DesktopAccountView, error) {
	if client == nil {
		return nil, response.ErrUnauthorized(40108, "desktop_client_missing", "desktop client context is required")
	}

	account, err := s.repo.Patch(ctx, repository.PatchDesktopAccountParams{
		DesktopID:     desktopID,
		WorkspaceID:   client.WorkspaceID,
		DisplayName:   req.DisplayName,
		Health:        req.Health,
		VerifiedAt:    req.VerifiedAt,
		Tags:          req.Tags,
		IfSyncVersion: req.IfSyncVersion,
	})
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, response.ErrConflict(40982, "desktop_account_sync_conflict", "desktop account sync version conflict")
		}
		return nil, response.ErrInternal(50084, "desktop_account_patch_failed", "failed to patch desktop account")
	}

	view := buildDesktopAccountView(account)
	return &view, nil
}

func (s *DesktopAccountService) Tombstone(ctx context.Context, client *repository.DesktopClient, desktopID uuid.UUID, ifSyncVersion int64) (*DesktopAccountView, error) {
	if client == nil {
		return nil, response.ErrUnauthorized(40108, "desktop_client_missing", "desktop client context is required")
	}

	account, err := s.repo.Tombstone(ctx, desktopID, client.WorkspaceID, ifSyncVersion)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, response.ErrConflict(40982, "desktop_account_sync_conflict", "desktop account sync version conflict")
		}
		return nil, response.ErrInternal(50085, "desktop_account_delete_failed", "failed to delete desktop account")
	}

	view := buildDesktopAccountView(account)
	return &view, nil
}

func (s *DesktopAccountService) RequestDelete(ctx context.Context, actor auth.Actor, desktopID uuid.UUID, undo bool) (*DesktopAccountView, error) {
	if actor.PrimaryWorkspaceID == 0 {
		return nil, response.ErrUnauthorized(40132, "workspace_scope_missing", "workspace context is required")
	}

	var (
		account *repository.DesktopAccount
		err     error
	)

	if undo {
		account, err = s.repo.ClearDeleteRequested(ctx, desktopID, actor.PrimaryWorkspaceID)
	} else {
		account, err = s.repo.MarkDeleteRequested(ctx, desktopID, actor.PrimaryWorkspaceID)
	}
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, response.ErrNotFound(40481, "desktop_account_not_found", "desktop account not found")
		}
		return nil, response.ErrInternal(50086, "desktop_account_request_delete_failed", "failed to update desktop account delete request")
	}

	view := buildDesktopAccountView(account)
	return &view, nil
}

func buildDesktopAccountView(account *repository.DesktopAccount) DesktopAccountView {
	var clientID *string
	if account.ClientID != nil {
		value := account.ClientID.String()
		clientID = &value
	}

	return DesktopAccountView{
		ID:                 account.DesktopID.String(),
		Platform:           account.Platform,
		PlatformUID:        account.PlatformUID,
		DisplayName:        account.DisplayName,
		Health:             account.Health,
		ClientID:           clientID,
		AccountFingerprint: account.AccountFingerprint,
		VerifiedAt:         account.VerifiedAt,
		Tags:               account.Tags,
		SyncVersion:        account.SyncVersion,
		DeletedAt:          account.DeletedAt,
		DeleteRequestedAt:  account.DeleteRequestedAt,
	}
}