// Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package httpcaddyfile

import (
	"encoding/json"
	"fmt"
	"log"

	"github.com/caddyserver/caddy/v2"
	"github.com/caddyserver/caddy/v2/caddyconfig"
	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
)

func (st *ServerType) parseMatcherDefinitions(d *caddyfile.Dispenser) (map[string]map[string]json.RawMessage, error) {
	matchers := make(map[string]map[string]json.RawMessage)
	for d.Next() {
		definitionName := d.Val()
		for d.NextBlock() {
			matcherName := d.Val()
			mod, err := caddy.GetModule("http.matchers." + matcherName)
			if err != nil {
				return nil, fmt.Errorf("getting matcher module '%s': %v", matcherName, err)
			}
			unm, ok := mod.New().(caddyfile.Unmarshaler)
			if !ok {
				return nil, fmt.Errorf("matcher module '%s' is not a Caddyfile unmarshaler", matcherName)
			}
			err = unm.UnmarshalCaddyfile(d.NewFromNextTokens())
			if err != nil {
				return nil, err
			}
			rm, ok := unm.(caddyhttp.RequestMatcher)
			if !ok {
				return nil, fmt.Errorf("matcher module '%s' is not a request matcher", matcherName)
			}
			if _, ok := matchers[definitionName]; !ok {
				matchers[definitionName] = make(map[string]json.RawMessage)
			}
			matchers[definitionName][matcherName] = caddyconfig.JSON(rm, nil)
		}
	}
	return matchers, nil
}

// directiveBuckets returns a list of middleware/handler directives.
// Buckets are ordered, and directives should be evaluated in their
// bucket order. Within a bucket, directives are not ordered. Hence,
// the return value has a slice of buckets, where each bucket is a
// map, which is a strongly-typed reminder that directives within a
// bucket are not ordered.
func directiveBuckets() []map[string]struct{} {
	directiveBuckets := []map[string]struct{}{
		// prefer odd-numbered buckets; evens are there for contingencies
		{}, // 0
		{}, // 1 - keep empty unless necessary
		{}, // 2
		{}, // 3 - first handlers, last responders
		{}, // 4
		{}, // 5 - middle of chain
		{}, // 6
		{}, // 7 - last handlers, first responders
		{}, // 8
		{}, // 9 - keep empty unless necessary
		{}, // 10
	}
	for _, mod := range caddy.GetModules("http.handlers") {
		if hd, ok := mod.New().(HandlerDirective); ok {
			bucket := hd.Bucket()
			if bucket < 0 || bucket >= len(directiveBuckets) {
				log.Printf("[ERROR] directive %s: bucket out of range [0-%d): %d; skipping",
					mod.Name, len(directiveBuckets), bucket)
				continue
			}
			directiveBuckets[bucket][mod.ID()] = struct{}{}
		}
	}
	return directiveBuckets
}