package projectinstance

import (
	"context"
	"fmt"

	"github.com/jackc/pgx/v5"
)

// AuthorOnlyPolicySnapshot 系统级「允许编制人兼任审核批准」总授权快照。
// 字段语义对齐 sysadmin.AuthorOnlyApprovalPolicy；本包不导入 sysadmin
// （module-boundaries.yaml 未授权），由组合根提供适配实现。
type AuthorOnlyPolicySnapshot struct {
	Allowed  bool
	Revision int64
}

// AuthorOnlyPolicySource 组合根注入的窄只读/事务锁接口。
type AuthorOnlyPolicySource interface {
	GetAuthorOnlyApprovalPolicy(ctx context.Context) (AuthorOnlyPolicySnapshot, error)
	LockAuthorOnlyApprovalPolicy(ctx context.Context, tx pgx.Tx) (AuthorOnlyPolicySnapshot, error)
}

func (s *Service) SetAuthorOnlyPolicySource(src AuthorOnlyPolicySource) {
	if s == nil {
		return
	}
	s.authorOnlyPolicy = src
}

func planUsesAuthorOnly(plan WorkflowPlan) bool {
	for _, st := range plan.Stages {
		if !st.Enabled {
			continue
		}
		for _, dt := range st.DocTasks {
			if dt.Enabled && dt.DutyPolicy == DutyPolicyAuthorOnly {
				return true
			}
		}
	}
	return false
}

func (s *Service) requireAuthorOnlyAllowed(ctx context.Context) (AuthorOnlyPolicySnapshot, error) {
	if s == nil || s.authorOnlyPolicy == nil {
		return AuthorOnlyPolicySnapshot{}, ErrAuthorOnlyPolicyUnavailable
	}
	snap, err := s.authorOnlyPolicy.GetAuthorOnlyApprovalPolicy(ctx)
	if err != nil {
		return AuthorOnlyPolicySnapshot{}, fmt.Errorf("%w: %v", ErrAuthorOnlyPolicyUnavailable, err)
	}
	if !snap.Allowed {
		return snap, ErrAuthorOnlyPolicyDisabled
	}
	return snap, nil
}

func (s *Service) loadAuthorOnlyCapability(ctx context.Context) GovernancePolicyCapability {
	cap := GovernancePolicyCapability{Allowed: false, Revision: 0}
	if s == nil || s.authorOnlyPolicy == nil {
		cap.BlockedReason = "unavailable"
		return cap
	}
	snap, err := s.authorOnlyPolicy.GetAuthorOnlyApprovalPolicy(ctx)
	if err != nil {
		cap.BlockedReason = "unavailable"
		return cap
	}
	cap.Allowed = snap.Allowed
	cap.Revision = snap.Revision
	if !snap.Allowed {
		cap.BlockedReason = "policy_disabled"
	}
	return cap
}

type activateAuthorOnlyLockKey struct{}

func withActivateAuthorOnlyLock(ctx context.Context, fn func(context.Context, pgx.Tx) (AuthorOnlyPolicySnapshot, error)) context.Context {
	if fn == nil {
		return ctx
	}
	return context.WithValue(ctx, activateAuthorOnlyLockKey{}, fn)
}

// runActivateAuthorOnlyLock 执行激活事务内策略行锁；第三个返回值表示是否注册过闭包。
func runActivateAuthorOnlyLock(ctx context.Context, tx pgx.Tx) (AuthorOnlyPolicySnapshot, error, bool) {
	fn, _ := ctx.Value(activateAuthorOnlyLockKey{}).(func(context.Context, pgx.Tx) (AuthorOnlyPolicySnapshot, error))
	if fn == nil {
		return AuthorOnlyPolicySnapshot{}, nil, false
	}
	snap, err := fn(ctx, tx)
	return snap, err, true
}