package router

import (
	"os"
	"strings"
)

// Match finds a handler for the given method and path (URL path, excludes groups)
func (r *LuaRouter) Match(method, path string, params *Params) (*node, bool) {
	params.Count = 0

	r.mu.RLock()
	root, exists := r.routes[method]
	r.mu.RUnlock()

	if !exists {
		return nil, false
	}

	segments := strings.Split(strings.Trim(path, "/"), "/")
	return r.matchPath(root, segments, params, 0)
}

// matchPath recursively matches a path against the routing tree
func (r *LuaRouter) matchPath(current *node, segments []string, params *Params, depth int) (*node, bool) {
	// Filter empty segments
	filteredSegments := segments[:0]
	for _, segment := range segments {
		if segment != "" {
			filteredSegments = append(filteredSegments, segment)
		}
	}
	segments = filteredSegments

	if len(segments) == 0 {
		if current.handler != "" {
			return current, true
		}
		if current.indexFile != "" {
			return current, true
		}
		return nil, false
	}

	segment := segments[0]
	remaining := segments[1:]

	// Try static child first
	if child, exists := current.staticChild[segment]; exists {
		if node, found := r.matchPath(child, remaining, params, depth+1); found {
			return node, true
		}
	}

	// Try parameter child
	if current.paramChild != nil {
		if params.Count < maxParams {
			params.Keys[params.Count] = current.paramChild.paramName
			params.Values[params.Count] = segment
			params.Count++
		}

		if node, found := r.matchPath(current.paramChild, remaining, params, depth+1); found {
			return node, true
		}

		params.Count--
	}

	// Fall back to index.lua
	if current.indexFile != "" {
		return current, true
	}

	return nil, false
}

// GetRouteInfo returns bytecode, script path, error, params, and found status
func (r *LuaRouter) GetRouteInfo(method, path []byte) ([]byte, string, error, *Params, bool) {
	// Convert to string for internal processing
	methodStr := string(method)
	pathStr := string(path)

	routeCacheKey := getCacheKey(methodStr, pathStr)
	routeCacheData := r.routeCache.Get(nil, routeCacheKey)

	// Fast path: found in cache
	if len(routeCacheData) > 0 {
		handlerPath := string(routeCacheData[8:])
		bytecodeKey := routeCacheData[:8]

		bytecode := r.bytecodeCache.Get(nil, bytecodeKey)

		n, exists := r.nodeForHandler(handlerPath)
		if !exists {
			r.routeCache.Del(routeCacheKey)
			return nil, "", nil, nil, false
		}

		// Check if recompilation needed
		if len(bytecode) > 0 {
			// For cached routes, we need to re-match to get params
			params := &Params{}
			r.Match(methodStr, pathStr, params)
			return bytecode, handlerPath, n.err, params, true
		}

		// Recompile if needed
		fileInfo, err := os.Stat(handlerPath)
		if err != nil || fileInfo.ModTime().After(n.modTime) {
			scriptPath := n.handler
			if scriptPath == "" {
				scriptPath = n.indexFile
			}

			fsPath := n.fsPath
			if fsPath == "" {
				fsPath = "/"
			}

			if err := r.compileWithMiddleware(n, fsPath, scriptPath); err != nil {
				params := &Params{}
				r.Match(methodStr, pathStr, params)
				return nil, handlerPath, n.err, params, true
			}

			newBytecodeKey := getBytecodeKey(handlerPath)
			bytecode = r.bytecodeCache.Get(nil, newBytecodeKey)

			newCacheData := make([]byte, 8+len(handlerPath))
			copy(newCacheData[:8], newBytecodeKey)
			copy(newCacheData[8:], handlerPath)
			r.routeCache.Set(routeCacheKey, newCacheData)

			params := &Params{}
			r.Match(methodStr, pathStr, params)
			return bytecode, handlerPath, n.err, params, true
		}

		params := &Params{}
		r.Match(methodStr, pathStr, params)
		return bytecode, handlerPath, n.err, params, true
	}

	// Slow path: lookup and compile
	params := &Params{}
	node, found := r.Match(methodStr, pathStr, params)
	if !found {
		return nil, "", nil, nil, false
	}

	scriptPath := node.handler
	if scriptPath == "" && node.indexFile != "" {
		scriptPath = node.indexFile
	}

	if scriptPath == "" {
		return nil, "", nil, nil, false
	}

	bytecodeKey := getBytecodeKey(scriptPath)
	bytecode := r.bytecodeCache.Get(nil, bytecodeKey)

	if len(bytecode) == 0 {
		fsPath := node.fsPath
		if fsPath == "" {
			fsPath = "/"
		}
		if err := r.compileWithMiddleware(node, fsPath, scriptPath); err != nil {
			return nil, scriptPath, node.err, params, true
		}
		bytecode = r.bytecodeCache.Get(nil, bytecodeKey)
	}

	// Cache the route
	cacheData := make([]byte, 8+len(scriptPath))
	copy(cacheData[:8], bytecodeKey)
	copy(cacheData[8:], scriptPath)
	r.routeCache.Set(routeCacheKey, cacheData)

	return bytecode, scriptPath, node.err, params, true
}

// GetRouteInfoString is a convenience method that accepts strings
func (r *LuaRouter) GetRouteInfoString(method, path string) ([]byte, string, error, *Params, bool) {
	return r.GetRouteInfo([]byte(method), []byte(path))
}