package platform

import (
	"database/sql"
	"encoding/json"
	"net/http"
	"reflect"
	"strings"
)

func validCanvasFrameExtensions(d map[string]any, v2 bool) bool {
	for _, key := range []string{"subgraph", "ports", "presentation"} {
		value, exists := d[key]
		if !exists {
			continue
		}
		if !v2 || d["kind"] != "frame" {
			return false
		}
		switch key {
		case "subgraph":
			m, ok := value.(map[string]any)
			if !ok || !canvasFields(m, "boardId") {
				return false
			}
			id, ok := m["boardId"].(string)
			if !ok || !uuidSlugPattern.MatchString(id) {
				return false
			}
		case "ports":
			ports, ok := value.([]any)
			if !ok || len(ports) > 4000 {
				return false
			}
			seen := map[string]bool{}
			for _, v := range ports {
				p, ok := v.(map[string]any)
				if !ok || !canvasFields(p, "id", "direction", "nodeId", "handle") {
					return false
				}
				id, ok := p["id"].(string)
				if !ok || !canvasID.MatchString(id) || seen[id] {
					return false
				}
				seen[id] = true
				node, ok := p["nodeId"].(string)
				if !ok || !canvasID.MatchString(node) || !canvasChoice(p["direction"], "input", "output") || !validCanvasPortHandle(p["handle"]) {
					return false
				}
			}
		case "presentation":
			m, ok := value.(map[string]any)
			if !ok || !canvasFields(m, "collapsed", "contentScale", "expandedSize", "collapsedSize") {
				return false
			}
			if v, exists := m["collapsed"]; exists {
				if _, ok := v.(bool); !ok {
					return false
				}
			}
			if v, exists := m["contentScale"]; exists && !canvasNumber(v, .05, 4) {
				return false
			}
			for _, key := range []string{"expandedSize", "collapsedSize"} {
				if v, exists := m[key]; exists {
					size, ok := v.(map[string]any)
					if !ok || !canvasFields(size, "width", "height") || !canvasNumber(size["width"], 32, 100000) || !canvasNumber(size["height"], 32, 100000) {
						return false
					}
				}
			}
		}
	}
	return true
}

func canvasNodeData(raw json.RawMessage) map[string]map[string]any {
	var doc map[string]any
	_ = json.Unmarshal(raw, &doc)
	result := map[string]map[string]any{}
	nodes, _ := doc["nodes"].([]any)
	for _, v := range nodes {
		n := v.(map[string]any)
		result[n["id"].(string)] = n["data"].(map[string]any)
	}
	return result
}

// Ordinary saves cannot create, replace, detach or retarget ownership/ports.
// Cross-board commands validate these changes while holding the workspace lock.
func validateCanvasRelations(r *http.Request, tx *sql.Tx, project, workspace, board string, before, after json.RawMessage) (bool, error) {
	old, next := canvasNodeData(before), canvasNodeData(after)
	rows, err := tx.QueryContext(r.Context(), `SELECT frame_id,child_board_id::text FROM canvas_subgraphs WHERE project=$1 AND workspace_id=$2 AND parent_board_id=$3 AND archived_at IS NULL`, project, workspace, board)
	if err != nil {
		return false, err
	}
	linked := map[string]string{}
	for rows.Next() {
		var frame, child string
		if err = rows.Scan(&frame, &child); err != nil {
			rows.Close()
			return false, err
		}
		linked[frame] = child
	}
	err = rows.Err()
	rows.Close()
	if err != nil {
		return false, err
	}
	for frame, child := range linked {
		d := next[frame]
		sub, _ := d["subgraph"].(map[string]any)
		if d["kind"] != "frame" || sub["boardId"] != child || !reflect.DeepEqual(old[frame]["ports"], d["ports"]) {
			return false, nil
		}
	}
	for id, d := range next {
		if sub, exists := d["subgraph"]; exists {
			m, _ := sub.(map[string]any)
			if linked[id] == "" || m["boardId"] != linked[id] {
				return false, nil
			}
		}
		if ports, ok := d["ports"].([]any); ok && len(ports) > 0 && linked[id] == "" {
			return false, nil
		}
		if frame, ok := d["frameId"].(string); ok && linked[frame] != "" {
			return false, nil
		}
	}
	// A child node referenced by its parent's ports must not disappear or change kind.
	var parentRaw json.RawMessage
	err = tx.QueryRowContext(r.Context(), `SELECT m.canvas_document FROM canvas_subgraphs s JOIN materials m ON m.project=s.project AND m.workspace_id=s.workspace_id AND m.id=s.parent_board_id WHERE s.project=$1 AND s.workspace_id=$2 AND s.child_board_id=$3 AND s.archived_at IS NULL`, project, workspace, board).Scan(&parentRaw)
	if err == sql.ErrNoRows {
		return true, nil
	}
	if err != nil {
		return false, err
	}
	for _, d := range canvasNodeData(parentRaw) {
		sub, _ := d["subgraph"].(map[string]any)
		if sub["boardId"] != board {
			continue
		}
		ports, _ := d["ports"].([]any)
		for _, v := range ports {
			p := v.(map[string]any)
			id, _ := p["nodeId"].(string)
			if next[id] == nil || next[id]["kind"] != old[id]["kind"] {
				return false, nil
			}
		}
	}
	return true, nil
}

func validCanvasPortHandle(value any) bool {
	if canvasChoice(value, "top", "right", "bottom", "left") {
		return true
	}
	h, ok := value.(string)
	return ok && strings.HasPrefix(h, "port:") && canvasID.MatchString(strings.TrimPrefix(h, "port:"))
}