package orchestration

import (
	"context"
	"strings"
	"sync"
	"testing"
	"time"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/agent"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/loop"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/tool"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/trace"
)

// parentSession 是分支测试把自己的子代理归属到的 flow 会话；它与网关发布时所依的
// web 聊天会话一致。
const parentSession = "web"

// secretArg 与 secretValue 是植入某次工具调用参数及其结果里的凭据形状字符串。二者都
// 不得出现在已发布的流程图中。
const (
	secretArg   = "sk-arg-0123456789abcdef"
	secretValue = "sk-live-0123456789abcdef"
)

// graphCapture 按会话记录发布器发出的每张流程图。
type graphCapture struct {
	mu        sync.Mutex
	bySession map[string]*trace.FlowGraph
	roundIDs  map[string][]string
}

func (c *graphCapture) publish(_ string, payload any) {
	g, ok := payload.(*trace.FlowGraph)
	if !ok || g == nil {
		return
	}
	c.mu.Lock()
	defer c.mu.Unlock()
	if c.bySession == nil {
		c.bySession = make(map[string]*trace.FlowGraph)
		c.roundIDs = make(map[string][]string)
	}
	c.bySession[g.SessionID] = g
	if ids := c.roundIDs[g.SessionID]; len(ids) == 0 || ids[len(ids)-1] != g.ID {
		c.roundIDs[g.SessionID] = append(ids, g.ID)
	}
}

func (c *graphCapture) graph(t *testing.T, session string) *trace.FlowGraph {
	t.Helper()
	c.mu.Lock()
	defer c.mu.Unlock()
	g := c.bySession[session]
	if g == nil {
		t.Fatalf("no flow graph published for session %q (captured sessions: %v)", session, c.sessionsLocked())
	}
	return g
}

func (c *graphCapture) ids(session string) []string {
	c.mu.Lock()
	defer c.mu.Unlock()
	return append([]string(nil), c.roundIDs[session]...)
}

func (c *graphCapture) has(session string) bool {
	c.mu.Lock()
	defer c.mu.Unlock()
	_, ok := c.bySession[session]
	return ok
}

func (c *graphCapture) sessionsLocked() []string {
	out := make([]string, 0, len(c.bySession))
	for s := range c.bySession {
		out = append(out, s)
	}
	return out
}

// toolThenFinalAdapter 的行为像一个先请求一次工具调用、随后作答的模型：请求里已带有
// 工具结果时，它返回脚本化的最终答复。依据请求（而不是调用计数器）来判断，使两个子
// 代理并发驱动同一个实例时它依然正确。
type toolThenFinalAdapter struct {
	toolName string
	args     map[string]any
	final    string
}

func (a *toolThenFinalAdapter) Name() string { return "mock" }

func (a *toolThenFinalAdapter) Chat(_ context.Context, req model.Request, _ model.Options) (model.Response, error) {
	for _, m := range req.Messages {
		if m.Role == model.RoleTool {
			return model.Response{Model: "mock-1", Content: a.final, StopReason: "end_turn"}, nil
		}
	}
	return model.Response{Model: "mock-1", ToolCalls: []model.ToolCall{
		{ID: "call-1", Name: a.toolName, Args: a.args},
	}}, nil
}

func (a *toolThenFinalAdapter) ChatStream(ctx context.Context, req model.Request, on func(model.StreamEvent)) (model.Response, error) {
	// 发出一个增量，使测试能检出循环是否把子代理的流转发到了调用方的 UI channel。
	if on != nil {
		on(model.StreamEvent{Kind: model.StreamKindTextDelta, Delta: "内部草稿"})
	}
	return a.Chat(ctx, req, model.Options{})
}

// echoTool 是一个最小工具：可选延迟之后回报一个脚本化结果，使两个分支的步骤在时间上
// 重叠。
type echoTool struct {
	name   string
	result any
	delay  time.Duration
}

func (e *echoTool) Name() string                        { return e.name }
func (e *echoTool) Description() string                 { return "echo the scripted result" }
func (e *echoTool) Parameters() (map[string]any, error) { return nil, nil }

func (e *echoTool) Execute(ctx context.Context, _ any) (any, error) {
	if e.delay > 0 {
		select {
		case <-time.After(e.delay):
		case <-ctx.Done():
			return nil, ctx.Err()
		}
	}
	return e.result, nil
}

// branchLoop 在给定 dispatcher 上构建带 tracing 与 flow 发布接线的真实循环，外加驱动
// 它的调度器 —— 即生产形状，只是少了模型供应商。
func branchLoop(t *testing.T, flow *loop.FlowPublisher, tracer *trace.Tracer, d *tool.Dispatcher, opts Options) *Scheduler {
	t.Helper()
	ad := &toolThenFinalAdapter{toolName: "echo", args: map[string]any{
		"command": "date",
		"api_key": secretArg,
	}, final: "子代理完成"}
	ag, err := agent.New("be brief", d, nil,
		agent.WithModel(ad, nil),
		agent.WithOptions(agent.Options{Model: "mock-1"}))
	if err != nil {
		t.Fatalf("agent.New: %v", err)
	}
	lp := loop.New(loop.Options{Agent: ag, Tools: d, Tracer: tracer, Flow: flow, MaxRounds: 8})
	opts.Loop = lp
	opts.Tracer = tracer
	opts.Flow = flow
	return newScheduler(t, opts)
}

// flowNodeByID 返回给定 id 的节点，不存在时判测试失败。
func flowNodeByID(t *testing.T, g *trace.FlowGraph, id string) trace.FlowNode {
	t.Helper()
	for _, n := range g.Nodes {
		if n.ID == id {
			return n
		}
	}
	t.Fatalf("no node %q in graph %s (nodes: %v)", id, g.ID, nodeIDs(g))
	return trace.FlowNode{}
}

func nodeIDs(g *trace.FlowGraph) []string {
	out := make([]string, 0, len(g.Nodes))
	for _, n := range g.Nodes {
		out = append(out, n.ID)
	}
	return out
}

// flowKindNodes 按图的插入顺序（即 span 开始的顺序，也就是泳道的步骤顺序）返回给定
// 类别的每个节点。
func flowKindNodes(g *trace.FlowGraph, kind string) []trace.FlowNode {
	out := make([]trace.FlowNode, 0, len(g.Nodes))
	for _, n := range g.Nodes {
		if n.Kind == kind {
			out = append(out, n)
		}
	}
	return out
}

// flowLaneNodes 按插入顺序返回某条泳道（一个可达集合）内的节点。
func flowLaneNodes(g *trace.FlowGraph, lane map[string]bool) []trace.FlowNode {
	out := make([]trace.FlowNode, 0, len(lane))
	for _, n := range g.Nodes {
		if lane[n.ID] {
			out = append(out, n)
		}
	}
	return out
}

// flowLaneChain 按插入时间返回该分支的各个步骤，并断言它们构成单条链：子代理根喂给
// 第一步，每一步喂给下一步。泳道交叉链接（某个步骤可从两个父节点到达）或游离节点都会
// 破坏链断言。
func flowLaneChain(t *testing.T, g *trace.FlowGraph, sub trace.FlowNode) []trace.FlowNode {
	t.Helper()
	lane := flowReachable(g, sub.ID)
	if len(lane) == 0 {
		t.Fatalf("subagent node %s (label %s) produced no steps", sub.ID, sub.Label)
	}
	chain := flowLaneNodes(g, lane)
	if !hasFlowEdge(g, sub.ID, chain[0].ID) {
		t.Fatalf("edges = %+v, want the lane to start at %s (root %s)", g.Edges, sub.ID, chain[0].ID)
	}
	for i := 1; i < len(chain); i++ {
		if !hasFlowEdge(g, chain[i-1].ID, chain[i].ID) {
			t.Fatalf("lane chain broken between %s and %s (edges: %+v)", chain[i-1].ID, chain[i].ID, g.Edges)
		}
	}
	return chain
}

// chainKinds 把一条泳道链渲染成 "llm>tool>llm"，用于失败信息。
func chainKinds(chain []trace.FlowNode) string {
	parts := make([]string, 0, len(chain))
	for _, n := range chain {
		parts = append(parts, n.Kind)
	}
	return strings.Join(parts, ">")
}

// flowSubagentNode 返回标签点名了给定子代理 id 的分支根。节点以 span id 为键，因此标签
// 才是标识其归属者的东西。
func flowSubagentNode(t *testing.T, g *trace.FlowGraph, subID string) trace.FlowNode {
	t.Helper()
	want := "subagent." + subID
	for _, n := range flowKindNodes(g, "subagent") {
		if n.Label == want || n.ID == want {
			return n
		}
	}
	t.Fatalf("no subagent node labelled %q in graph %s (nodes: %v)", want, g.ID, nodeIDs(g))
	return trace.FlowNode{}
}

// flowReachable 返回从 id 可达的节点 id 集合，不含 id 自身。
func flowReachable(g *trace.FlowGraph, id string) map[string]bool {
	out := make(map[string]bool)
	queue := []string{id}
	for len(queue) > 0 {
		from := queue[0]
		queue = queue[1:]
		for _, e := range g.Edges {
			if e.From != from || out[e.To] || e.To == id {
				continue
			}
			out[e.To] = true
			queue = append(queue, e.To)
		}
	}
	return out
}

func hasFlowEdge(g *trace.FlowGraph, from, to string) bool {
	for _, e := range g.Edges {
		if e.From == from && e.To == to {
			return true
		}
	}
	return false
}

// flowLogEvent 返回该节点给定类型的日志条目。
func flowLogEvent(t *testing.T, n trace.FlowNode, typ string) trace.Event {
	t.Helper()
	for _, ev := range n.Log {
		if ev.Type == typ {
			return ev
		}
	}
	t.Fatalf("node %s has no %q log entry (log: %+v)", n.ID, typ, n.Log)
	return trace.Event{}
}