package main

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"verstak/internal/core/nodes"
)

type VaultCheckResult struct {
	TotalNodes            int      `json:"total_nodes"`
	TotalFiles            int      `json:"total_files"`
	NodesWithFsPath       int      `json:"nodes_with_fs_path"`
	FoldersOnDisk         int      `json:"folders_on_disk"`
	FilesOnDisk           int      `json:"files_on_disk"`
	FilesMissing          int      `json:"files_missing"`
	PathEscapeCount       int      `json:"path_escape_count"`
	ParentIDEmptyCount    int      `json:"parent_id_empty_count"`
	OrphanDescendantCount int      `json:"orphan_descendant_count"`
	Errors                []string `json:"errors,omitempty"`
	Details               []string `json:"details,omitempty"`
	Healthy               bool     `json:"healthy"`
}

func (a *App) VaultCheck() (*VaultCheckResult, error) {
	result := &VaultCheckResult{Healthy: true}

	// Build a set of all node IDs for ancestor check
	allNodes := make(map[string]*nodes.Node)
	roots, err := a.nodes.ListRoots(true)
	if err != nil {
		return nil, fmt.Errorf("list roots: %w", err)
	}
	var collectDescendants func(id string)
	collectDescendants = func(id string) {
		n, err := a.nodes.Get(id)
		if err == nil {
			allNodes[n.ID] = n
		}
		children, _ := a.nodes.ListChildren(id, true)
		for _, c := range children {
			allNodes[c.ID] = &c
			collectDescendants(c.ID)
		}
	}
	for _, n := range roots {
		allNodes[n.ID] = &n
		collectDescendants(n.ID)
	}

	// Check parent_id consistency
	for id, n := range allNodes {
		if !n.IsRoot() && n.ParentID != nil && *n.ParentID == "" {
			result.ParentIDEmptyCount++
			result.Errors = append(result.Errors,
				fmt.Sprintf("node %s (%s): parent_id is empty string, should be nil", id, n.Title))
			result.Healthy = false
		}
	}

	// Check each node
	for _, n := range allNodes {
		if n.IsDeleted() {
			continue
		}
		result.TotalNodes++

		// Check if ancestor is deleted
		if n.ParentID != nil && *n.ParentID != "" {
			if parent, ok := allNodes[*n.ParentID]; ok && parent.IsDeleted() {
				result.OrphanDescendantCount++
				result.Errors = append(result.Errors,
					fmt.Sprintf("node %s (%s) is active but parent %s is deleted", n.ID, n.Title, *n.ParentID))
				result.Healthy = false
			}
		}

		// Check fs_path
		isFolderLike := n.Type != nodes.TypeNote && n.Type != nodes.TypeFile
		if isFolderLike && n.FsPath != "" {
			result.NodesWithFsPath++
			physPath := filepath.Join(a.vault, n.FsPath)
			rel, err := filepath.Rel(a.vault, physPath)
			if err != nil || strings.HasPrefix(rel, "..") {
				result.PathEscapeCount++
				result.Errors = append(result.Errors,
					fmt.Sprintf("node %s (%s): fs_path escapes vault: %s", n.ID, n.Title, n.FsPath))
				result.Healthy = false
				continue
			}
			if info, err := os.Stat(physPath); err == nil {
				if info.IsDir() {
					result.FoldersOnDisk++
				}
			} else {
				result.FilesMissing++
				result.Details = append(result.Details,
					fmt.Sprintf("node %s (%s): folder missing on disk: %s", n.ID, n.Title, physPath))
			}
		}
	}

	// Check file records
	rows, err := a.db.Query(`SELECT f.id, f.node_id, f.path, f.storage_mode FROM files f LEFT JOIN nodes n ON f.node_id = n.id WHERE n.deleted_at IS NULL`)
	if err != nil {
		result.Errors = append(result.Errors, fmt.Sprintf("query files: %v", err))
		result.Healthy = false
		return result, nil
	}
	defer rows.Close()

	for rows.Next() {
		var id, nodeID, path, mode string
		if err := rows.Scan(&id, &nodeID, &path, &mode); err != nil {
			continue
		}
		result.TotalFiles++

		if mode == "vault" {
			absPath := filepath.Join(a.vault, path)
			rel, err := filepath.Rel(a.vault, absPath)
			if err != nil || strings.HasPrefix(rel, "..") {
				result.PathEscapeCount++
				result.Errors = append(result.Errors,
					fmt.Sprintf("file %s: path escapes vault: %s", id, path))
				result.Healthy = false
				continue
			}
			if _, err := os.Stat(absPath); err == nil {
				result.FilesOnDisk++
			} else {
				result.FilesMissing++
				result.Details = append(result.Details,
					fmt.Sprintf("file %s (%s): missing on disk: %s", id, path, absPath))
			}
		}
	}

	if result.FilesMissing > 0 || result.PathEscapeCount > 0 ||
		result.ParentIDEmptyCount > 0 || result.OrphanDescendantCount > 0 {
		result.Healthy = false
	}
	return result, nil
}