package buildrun

import (
	"sort"
	"sync"

	"git.novox.be/novox/mesh-delivery/sdk/buildstep"
)

// LanguageOf is the language each build module's toolchain reports hold.
var LanguageOf = map[string]string{GoBuildModule: "go", NodeBuildModule: "typescript"}

// ToolchainsHeardState is the builder's old state section of the toolchains it heard (design 47 G §604, §546): one key
// <node>.<language>, the toolchain as the build seat said it.
const (
	ToolchainsHeardState  = "toolchains-heard"
	ToolchainsHeardBucket = "mesh-delivery-builder_" + ToolchainsHeardState
)

// ToolchainSet holds each node's toolchain of a language, as the builder heard it (design 47 G §604). Safe for use from
// the consumer and from a build at once.
type ToolchainSet struct {
	mu sync.Mutex
	by map[string]map[string]buildstep.Toolchain // language -> node -> entry
}

// Set takes a node's toolchain in and answers whether the language's entries changed (a node's version, recipe or
// digest, or a node appearing).
func (s *ToolchainSet) Set(node string, tc buildstep.Toolchain) bool {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.by == nil {
		s.by = map[string]map[string]buildstep.Toolchain{}
	}
	if s.by[tc.Language] == nil {
		s.by[tc.Language] = map[string]buildstep.Toolchain{}
	}
	cur, had := s.by[tc.Language][node]
	s.by[tc.Language][node] = tc
	return !had || cur.Version != tc.Version || cur.Recipe != tc.Recipe || cur.Digest != tc.Digest
}

// Delete takes a node's toolchain of a language out and answers whether it was held.
func (s *ToolchainSet) Delete(node, language string) bool {
	s.mu.Lock()
	defer s.mu.Unlock()
	if _, had := s.by[language][node]; !had {
		return false
	}
	delete(s.by[language], node)
	return true
}

// Entries are the nodes' entries of a language, in no particular order.
func (s *ToolchainSet) Entries(language string) []buildstep.NodeToolchain {
	s.mu.Lock()
	defer s.mu.Unlock()
	var out []buildstep.NodeToolchain
	for node, tc := range s.by[language] {
		out = append(out, buildstep.NodeToolchain{Node: node, Toolchain: tc})
	}
	return out
}

// AgreedDigest is a digest of the agreed version and the nodes reporting it.
type AgreedDigest struct {
	Digest string
	Nodes  []string
}

// Digests are the digests the nodes reporting the agreed toolchain's version report, sorted by digest, each with its
// nodes sorted (design 47 G §472, §574). A node that reports no digest is left out.
func Digests(entries []buildstep.NodeToolchain, agreed buildstep.Toolchain) []AgreedDigest {
	by := map[string][]string{}
	for _, e := range entries {
		if e.Version == agreed.Version && e.Recipe == agreed.Recipe && e.Digest != "" {
			by[e.Digest] = append(by[e.Digest], e.Node)
		}
	}
	out := make([]AgreedDigest, 0, len(by))
	for d, nodes := range by {
		sort.Strings(nodes)
		out = append(out, AgreedDigest{Digest: d, Nodes: nodes})
	}
	sort.Slice(out, func(i, j int) bool { return out[i].Digest < out[j].Digest })
	return out
}

// The builder's tools over the toolchains it heard (design 47 G §604, §546).
const (
	ToolchainsTool     = "builder_toolchains"
	ToolchainsDropTool = "builder_toolchains_drop"
)

// Put takes a change of a build module's toolchains bucket in: a put of a node's entry (key <node>.<language>) or its
// delete. It answers whether the language's entries changed (a node's version or recipe, or a node appearing or going).
// A key or a value that is not an entry of the module's language is left out.
func (s *ToolchainSet) Put(module, key string, value []byte, deleted bool) bool {
	language, ok := LanguageOf[module]
	if !ok {
		return false
	}
	node, keyLanguage, err := buildstep.ParseToolchainKey(key)
	if err != nil || keyLanguage != language {
		return false
	}
	s.mu.Lock()
	defer s.mu.Unlock()
	if deleted {
		if _, had := s.by[language][node]; !had {
			return false
		}
		delete(s.by[language], node)
		return true
	}
	tc, err := buildstep.DecodeToolchain(value)
	if err != nil || tc.Language != language {
		return false
	}
	if s.by == nil {
		s.by = map[string]map[string]buildstep.Toolchain{}
	}
	if s.by[language] == nil {
		s.by[language] = map[string]buildstep.Toolchain{}
	}
	cur, had := s.by[language][node]
	s.by[language][node] = tc
	return !had || cur.Version != tc.Version || cur.Recipe != tc.Recipe || cur.Digest != tc.Digest
}