package workflowdef

import (
	"regexp"
	"strings"
)

// legacyToCanonical 是 D12 的旧任务键 → 新任务键。
// 冻结实例继续持有旧键；新发布的清单使用新键。两边必须指向同一套步骤和模板。
var legacyToCanonical = map[string]string{
	"intake":                 "bd_intake",
	"research":               "bd_research",
	"feasibility_dev":        "bd_feasibility_dev",
	"feasibility_reg":        "bd_feasibility_reg",
	"user_requirements":      "bd_user_requirements",
	"prelim_design":          "bd_prelim_design",
	"cdo_quote":              "bd_cdo_quote",
	"system_reqs":            "pm_system_reqs",
	"test_manager":           "tm_system_verification",
	"software_charter":       "sw_software_charter",
	"source_inventory":       "sw_source_inventory",
	"current_state_audit":    "sw_current_state_audit",
	"architecture_baseline":  "sw_architecture_baseline",
	"software_risk_register": "sw_software_risk_register",
	"product_requirements":   "sw_product_requirements",
	"scope_backlog":          "sw_scope_backlog",
	"target_architecture":    "sw_target_architecture",
	"decision_log":           "sw_decision_log",
	"bootstrap_roadmap":      "sw_bootstrap_roadmap",
	"verification_strategy":  "sw_verification_strategy",
	"operations_baseline":    "sw_operations_baseline",
	"bootstrap_readiness":    "sw_bootstrap_readiness",
	"change_brief":           "sw_change_brief",
	"implementation_plan":    "sw_implementation_plan",
	"change_manifest":        "sw_change_manifest",
	"adr_delta":              "sw_adr_delta",
	"test_report":            "sw_test_report",
	"security_review":        "sw_security_review",
	"release_plan":           "sw_release_plan",
	"release_notes":          "sw_release_notes",
	"retrospective":          "sw_retrospective",
	"backlog_delta":          "sw_backlog_delta",
}

var canonicalToLegacy map[string]string

func init() {
	canonicalToLegacy = make(map[string]string, len(legacyToCanonical))
	for legacy, canonical := range legacyToCanonical {
		canonicalToLegacy[canonical] = legacy
	}
}

// CanonicalTaskKey 把旧键收成发布用的新键。未知键（含 rd_*）原样返回。
func CanonicalTaskKey(key string) string {
	key = strings.TrimSpace(key)
	if canonical, ok := legacyToCanonical[key]; ok {
		return canonical
	}
	return key
}

// ImplementationTaskKey 把新键收成现有步骤开关仍使用的旧键。
// 存量执行路径不改写；新键只是别名。
func ImplementationTaskKey(key string) string {
	key = strings.TrimSpace(key)
	if legacy, ok := canonicalToLegacy[key]; ok {
		return legacy
	}
	return key
}

// SameTaskKey 判断两个键是否同一任务（旧键与新键视为相同）。
func SameTaskKey(a, b string) bool {
	ca := CanonicalTaskKey(a)
	cb := CanonicalTaskKey(b)
	return ca != "" && ca == cb
}

var namespacedDocID = regexp.MustCompile(`^(doc_proj\d+_)(.+)$`)

// AlternateDocIDs 给出同一文档的另一种键名形式。
// 账本不批量迁移：旧 ID 仍可查，新 ID 也要能指回旧行。
func AlternateDocIDs(docID string) []string {
	m := namespacedDocID.FindStringSubmatch(strings.TrimSpace(docID))
	if len(m) != 3 {
		return nil
	}
	prefix, suffix := m[1], m[2]
	var out []string
	if canonical := CanonicalTaskKey(suffix); canonical != suffix {
		out = append(out, prefix+canonical)
	}
	if legacy := ImplementationTaskKey(suffix); legacy != suffix {
		out = append(out, prefix+legacy)
	}
	return out
}