package intent

import (
	"fmt"
	"regexp"
	"sort"
	"strings"
	"sync"
	"unicode/utf8"

	"chat-agent-system/internal/squad"
	"chat-agent-system/internal/workflowdef"
)

// docWorkflowScope 提供「文档标题/任务键 → 归属工作流」索引，
// 使填槽（target_doc / target_task）只命中当前激活工作流；
// 显式点名他流文档时打 workflow_scope_mismatch 标记并给出切换引导，不误填。

// docWorkflowIndex 文档标题/别名 → 归属工作流 key 集合（跨流歧义标题会有多个值）。
type docWorkflowIndex struct {
	phraseToWorkflows map[string][]string
	// phraseWorkflowTask 供「同名文档分属多流」时按激活流改路由（如 系统需求规格书 → pm_/rd_）。
	phraseWorkflowTask map[string]map[string]string
	sortedPhrases      []string
	nameToKey          map[string]string
}

var (
	docScopeOnce  sync.Once
	docScopeIndex *docWorkflowIndex
)

// 存量别名与历史叫法 → 规范工作流键（与 internal/workflowdef/keyspace.go 的旧任务键前缀对齐）。
var docScopeWorkflowAliases = map[string]string{
	"bd":   "main",
	"urs":  "product_manager",
	"tm":   "test_manager",
	"rd":   "rdev",
	"sw":   "software_bootstrap",
	"main": "main",
}

// docScopeManualEntries 是清单之外的补充叫法（历史词表与口语别名）。
// 只收录语义明确的标题；模糊短别名（如「需求表」）不在此列，维持原有兜底。
var docScopeManualEntries = []struct {
	workflow  string
	phrases   []string
	reference string // 借用该任务键的清单标题；可为空
}{
	{workflow: "main", phrases: []string{"用户初始需求收集表", "用户初始需求表", "用户需求收集表", "需求收集表", "技术与市场调研报告", "CDO报价单", "初步报价单"}},
	{workflow: "product_manager", phrases: []string{"URS", "用户需求规格"}},
	{workflow: "test_manager", phrases: []string{"系统验证方案", "验证方案及计划"}},
	// 「设计方案」在历史词表里指商务流的系统初步设计方案；研发流的同名文档用全称「系统设计方案」消歧。
	{workflow: "main", phrases: []string{"设计方案"}, reference: "bd_prelim_design"},
}

// docScopeUnusablePhrase 过短的短语（含 UN/BOM 类记号）易命中无关句子，不入索引。
func docScopeUnusablePhrase(phrase string) bool {
	return utf8.RuneCountInString(phrase) < 2
}

func buildDocWorkflowIndex() *docWorkflowIndex {
	idx := &docWorkflowIndex{
		phraseToWorkflows:  map[string][]string{},
		phraseWorkflowTask: map[string]map[string]string{},
		nameToKey:          map[string]string{},
	}
	add := func(workflow, phrase, taskKey string) {
		phrase = strings.TrimSpace(phrase)
		if phrase == "" || docScopeUnusablePhrase(phrase) {
			return
		}
		dup := false
		for _, existing := range idx.phraseToWorkflows[phrase] {
			if existing == workflow {
				dup = true
				break
			}
		}
		if !dup {
			idx.phraseToWorkflows[phrase] = append(idx.phraseToWorkflows[phrase], workflow)
		}
		if taskKey != "" {
			byWF, ok := idx.phraseWorkflowTask[phrase]
			if !ok {
				byWF = map[string]string{}
				idx.phraseWorkflowTask[phrase] = byWF
			}
			if _, exists := byWF[workflow]; !exists {
				byWF[workflow] = taskKey
			}
		}
	}

	for _, manifestFile := range workflowdef.V2ManifestFiles {
		def, err := workflowdef.LoadManifestDefinition(manifestFile)
		if err != nil || def.WorkflowKey == "" {
			continue
		}
		for _, st := range def.Stages {
			for _, dt := range st.DocTasks {
				idx.nameToKey[dt.Key] = def.WorkflowKey
				add(def.WorkflowKey, dt.Title, dt.Key)
				if dt.OutputDocTitle != "" && dt.OutputDocTitle != dt.Title {
					add(def.WorkflowKey, dt.OutputDocTitle, dt.Key)
				}
				if meta, ok := squad.LookupRDevTask(dt.Key); ok {
					add(def.WorkflowKey, meta.Title, dt.Key)
					for _, alias := range meta.Aliases {
						add(def.WorkflowKey, alias, dt.Key)
					}
				}
			}
		}
	}
	for _, entry := range docScopeManualEntries {
		for _, p := range entry.phrases {
			add(entry.workflow, p, "")
		}
		if entry.reference != "" {
			def, err := workflowdef.LoadManifestDefinition(entry.workflow + ".v2.json")
			if err == nil {
				for _, st := range def.Stages {
					for _, dt := range st.DocTasks {
						if dt.Key == entry.reference {
							add(entry.workflow, dt.Title, dt.Key)
						}
					}
				}
			}
		}
	}

	phrases := make([]string, 0, len(idx.phraseToWorkflows))
	for p := range idx.phraseToWorkflows {
		phrases = append(phrases, p)
	}
	sort.Slice(phrases, func(i, j int) bool {
		li := utf8.RuneCountInString(phrases[i])
		lj := utf8.RuneCountInString(phrases[j])
		if li != lj {
			return li > lj
		}
		return phrases[i] < phrases[j]
	})
	idx.sortedPhrases = phrases
	return idx
}

func getDocWorkflowIndex() *docWorkflowIndex {
	docScopeOnce.Do(func() {
		docScopeIndex = buildDocWorkflowIndex()
	})
	return docScopeIndex
}

// taskKeyWorkflowOwner 按任务键推断归属工作流（旧键与新键均可；未知返回空）。
func taskKeyWorkflowOwner(taskKey string) string {
	taskKey = strings.TrimSpace(taskKey)
	if taskKey == "" {
		return ""
	}
	idx := getDocWorkflowIndex()
	if wf, ok := idx.nameToKey[taskKey]; ok {
		return wf
	}
	if canonical := workflowdef.CanonicalTaskKey(taskKey); canonical != taskKey {
		if wf, ok := idx.nameToKey[canonical]; ok {
			return wf
		}
	}
	prefix := taskKey
	if i := strings.Index(taskKey, "_"); i > 0 {
		prefix = taskKey[:i]
	}
	return docScopeWorkflowAliases[prefix]
}

// docNameHit 记录文档短语命中的归属集合。
type docNameHit struct {
	Phrase    string
	Workflows []string
}

// matchDocPhrasesForScope 在输入中查找命中的文档标题/别名短语（最长优先）。
// 长短语占用的字符区间不再参与更短短语匹配，防止「用户需求规格书」拆出「需求规格」。
func matchDocPhrasesForScope(input string) []docNameHit {
	idx := getDocWorkflowIndex()
	used := make([]bool, len(input))
	var hits []docNameHit
	for _, phrase := range idx.sortedPhrases {
		for start := 0; start < len(input); {
			pos := strings.Index(input[start:], phrase)
			if pos < 0 {
				break
			}
			abs := start + pos
			overlap := false
			for k := abs; k < abs+len(phrase); k++ {
				if used[k] {
					overlap = true
					break
				}
			}
			for k := abs; k < abs+len(phrase); k++ {
				used[k] = true
			}
			if !overlap {
				hits = append(hits, docNameHit{Phrase: phrase, Workflows: idx.phraseToWorkflows[phrase]})
			}
			start = abs + len(phrase)
		}
	}
	return hits
}

// docScopeForPhrase 返回某文档短语的归属工作流集合。
func docScopeForPhrase(phrase string) ([]string, bool) {
	idx := getDocWorkflowIndex()
	wfs, ok := idx.phraseToWorkflows[strings.TrimSpace(phrase)]
	return wfs, ok
}

// activeScopedTaskKey 同名文档分属多流时，返回当前激活流的任务键（执行键形态）。
func activeScopedTaskKey(phrase, activeWorkflow string) (string, bool) {
	if activeWorkflow == "" {
		return "", false
	}
	idx := getDocWorkflowIndex()
	byWF, ok := idx.phraseWorkflowTask[strings.TrimSpace(phrase)]
	if !ok {
		return "", false
	}
	key, ok := byWF[activeWorkflow]
	if !ok || key == "" {
		return "", false
	}
	return workflowdef.ImplementationTaskKey(key), true
}

// docWorkflowScopeMarker 检查输入是否显式点名了非激活工作流的受控文档。
// 返回 (他流文档标题, 归属工作流 key 列表, 是否命中跨流)。
// activeWorkflow 为空（存量单流 / planning 态）时一律不判跨流，保持现状行为。
func docWorkflowScopeMarker(input, activeWorkflow string) (string, []string, bool) {
	if activeWorkflow == "" {
		return "", nil, false
	}
	for _, hit := range matchDocPhrasesForScope(input) {
		owns := false
		for _, wf := range hit.Workflows {
			if wf == activeWorkflow {
				owns = true
				break
			}
		}
		if !owns {
			return hit.Phrase, hit.Workflows, true
		}
	}
	return "", nil, false
}

// markWorkflowScopeMismatch 在槽位上打跨流标记。
func markWorkflowScopeMismatch(slots map[string]string, doc string, workflows []string) {
	if slots == nil || doc == "" {
		return
	}
	slots[SlotWorkflowScopeMismatch] = "true"
	slots[SlotMismatchedDoc] = doc
	slots[SlotMismatchedWorkflow] = strings.Join(workflows, ",")
}

// scopeMismatchClarify 若槽位带跨流标记则返回引导话术，否则空串。
func scopeMismatchClarify(slots map[string]string, activeWorkflow string) string {
	if slots == nil || slots[SlotWorkflowScopeMismatch] != "true" {
		return ""
	}
	workflows := []string{}
	if v := slots[SlotMismatchedWorkflow]; v != "" {
		workflows = strings.Split(v, ",")
	}
	return workflowScopeGuidanceQuestion(slots[SlotMismatchedDoc], workflows, activeWorkflow)
}

// fillTargetDocSlot 按工作流作用域规则填充 target_doc 槽位：
// 显式点名他流文档 → 不填 target_doc，改打 workflow_scope_mismatch 标记；
// 否则保持原逻辑（显式名 → ActiveDocID 回退）。
func fillTargetDocSlot(slots map[string]string, input string, userCtx *ContextSnapshot) {
	if slots == nil {
		return
	}
	active := ""
	if userCtx != nil {
		active = userCtx.ActiveWorkflowKey
	}
	if doc, wfs, mismatched := docWorkflowScopeMarker(input, active); mismatched {
		markWorkflowScopeMismatch(slots, doc, wfs)
		return
	}
	if doc := extractDocName(input); doc != "" {
		slots[SlotTargetDoc] = doc
		return
	}
	if userCtx != nil && userCtx.ActiveDocID != "" {
		slots[SlotTargetDoc] = userCtx.ActiveDocID
	}
}

// WorkflowScopeGuidanceQuestion 生成「该文档属于 XX 工作流，请先切换」引导话术。
func WorkflowScopeGuidanceQuestion(doc string, workflows []string, activeWorkflow string) string {
	return workflowScopeGuidanceQuestion(doc, workflows, activeWorkflow)
}

// WorkflowDisplayName 返回工作流键的中文展示名。
func WorkflowDisplayName(key string) string {
	return workflowDisplayName(key)
}

// TaskKeyWorkflowOwner 按任务键推断归属工作流（旧键与新键均可；未知返回空）。
func TaskKeyWorkflowOwner(taskKey string) string {
	return taskKeyWorkflowOwner(taskKey)
}

// workflowScopeGuidanceQuestion 生成「该文档属于 XX 工作流，请先切换」引导话术。
func workflowScopeGuidanceQuestion(doc string, workflows []string, activeWorkflow string) string {
	names := make([]string, 0, len(workflows))
	for _, wf := range workflows {
		names = append(names, workflowDisplayName(wf))
	}
	owner := "其他工作流"
	if len(names) > 0 {
		owner = strings.Join(names, " / ")
	}
	return fmt.Sprintf(
		"您提到的文档「%s」属于【%s】，当前激活工作流为【%s】。已阻止跨工作流操作，请先切换到对应工作流后再操作，或改为点名当前工作流的文档。",
		doc, owner, workflowDisplayName(activeWorkflow),
	)
}

func workflowDisplayName(key string) string {
	switch key {
	case "main":
		return "商务对接流程"
	case "product_manager":
		return "智能产品经理流程"
	case "test_manager":
		return "智能测试工程师流程"
	case "rdev":
		return "研发设计控制流程"
	case "software_bootstrap":
		return "软件项目自举流程"
	case "software_delivery":
		return "软件交付迭代流程"
	default:
		return key
	}
}

// activeWorkflowKeyOf 从上下文快照安全读取激活工作流键。
func activeWorkflowKeyOf(userCtx *ContextSnapshot) string {
	if userCtx == nil {
		return ""
	}
	return userCtx.ActiveWorkflowKey
}

// docGovActionKeywords 触发受控文档治理写动作的关键词。
var docGovActionKeywords = []string{
	"驳回", "退回", "终审批准", "批准", "审核通过", "审阅通过", "评审通过", "准予",
	"认领", "送审", "提交审核", "发起审核", "提审",
}

func hasDocGovActionKeyword(input string) bool {
	for _, k := range docGovActionKeywords {
		if strings.Contains(input, k) {
			return true
		}
	}
	return false
}

// docGovScopePreempt 治理写动作显式点名他流文档时，前置剪枝为跨工作流拦截，
// 不落入任何 DOCGOV_* 写意图。无激活工作流（存量单流 / planning 态）时不拦截。
func docGovScopePreempt(input string, userCtx *ContextSnapshot) *CandidateIntent {
	active := activeWorkflowKeyOf(userCtx)
	if active == "" || !hasDocGovActionKeyword(input) {
		return nil
	}
	doc, owners, mismatched := docWorkflowScopeMarker(input, active)
	if !mismatched {
		return nil
	}
	slots := make(map[string]string)
	markWorkflowScopeMismatch(slots, doc, owners)
	return &CandidateIntent{
		Intent:                IntentUnsupportedAction,
		Confidence:            0.94,
		Branch:                BranchNewIntentPreempt,
		FilledSlots:           slots,
		Reasoning:             fmt.Sprintf("受控文档治理动作显式点名他流文档「%s」，前置剪枝为跨工作流拦截", doc),
		ClarificationQuestion: workflowScopeGuidanceQuestion(doc, owners, active),
	}
}

// docNameIDPattern 匹配显式文档 ID（doc-xxx 或 doc_projN_xxx）。
var docNameIDPattern = regexp.MustCompile(`(doc[_-][a-zA-Z0-9_-]+)`)

// hasExplicitDocID 判断输入是否携带显式文档 ID（视为用户精确指向，交由消费端裁决）。
func hasExplicitDocID(input string) bool {
	return docNameIDPattern.FindString(input) != ""
}