package main

import (
	"context"
	"encoding/json"
	orbit "git.yuntuo.hk/k2safe/orbit/sdk/go"
	"sync"
)

// invocation 固定首次调用的任务/尝试身份，重复调用不得覆盖首条证据。
type invocation struct {
	index     int    // index 输入中的计划序号。
	attemptID string // attemptID 首次调用的尝试。
	calls     int    // calls 同一任务的调用次数。
}

// invocationLog 最多保存预期任务数个身份，异常输入不能无限增长内存。
type invocationLog struct {
	mu       sync.Mutex             // mu 保护多个Worker并发回调。
	limit    int                    // limit 可存任务身份上限。
	calls    map[string]*invocation // calls 以任务身份记录真实调用。
	invalid  int                    // invalid 无法核验的输入次数。
	overflow int                    // overflow 超出身份预算的调用次数。
}

func newInvocationLog(n int) *invocationLog {
	return &invocationLog{limit: n, calls: map[string]*invocation{}}
}
func (l *invocationLog) handler(run context.Context, c config, runID string) orbit.WorkerHandler {
	return orbit.WorkerHandler{Capability: orbit.WorkerCapability{Handler: handlerName(runID), HandlerVersion: "v1", PayloadVersion: "v1"}, Handle: func(ctx context.Context, e orbit.WorkerExecution) (json.RawMessage, error) {
		payload, ok := decodePayload(e.Task.Payload)
		if !ok || payload.Schedule < 0 || payload.Schedule >= c.Schedules || !matchesTask(e.Task, c, runID, payload.Schedule) || !validID(e.AttemptID) || e.Epoch != 1 || e.ConcurrencyToken != 0 {
			l.mu.Lock()
			l.invalid++
			l.mu.Unlock()
			return nil, &orbit.WorkerFailure{Code: "SCHEDULE_INPUT_MISMATCH"}
		}
		l.mu.Lock()
		existing := l.calls[e.Task.ID]
		if existing != nil {
			existing.calls++
			l.mu.Unlock()
			return nil, &orbit.WorkerFailure{Code: "DUPLICATE_INVOCATION"}
		}
		if len(l.calls) >= l.limit {
			l.overflow++
			l.mu.Unlock()
			return nil, &orbit.WorkerFailure{Code: "INVOCATION_LIMIT"}
		}
		l.calls[e.Task.ID] = &invocation{index: payload.Schedule, attemptID: e.AttemptID, calls: 1}
		l.mu.Unlock()
		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		case <-run.Done():
			return nil, run.Err()
		default:
		}
		return e.Task.Payload, nil
	}}
}
func (l *invocationLog) summarize(r *scheduleReport, o *observations) {
	l.mu.Lock()
	defer l.mu.Unlock()
	r.Errors["INVALID_HANDLER_INPUT"] += l.invalid
	r.Errors["HANDLER_IDENTITY_LIMIT"] += l.overflow
	for taskID, call := range l.calls {
		r.HandlerCalls += call.calls
		if call.calls > 1 {
			r.DuplicateInvocations += call.calls - 1
		}
		s := o.tasks[taskID]
		if s == nil || !s.verified || s.attemptID != call.attemptID || o.plans[s.occurrence.ScheduleID].index != call.index {
			r.UnconfirmedInvocations += call.calls
		}
	}
	for taskID, s := range o.tasks {
		if s.verified && l.calls[taskID] == nil {
			r.Errors["MISSING_LOCAL_INVOCATION"]++
		}
	}
}