first commit

pigo/internal/agentcore/helpers.go

@@ -0,0 +1,60 @@
+package agentcore
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+)
+
+// ContentToText flattens text blocks of a content list into a single string,
+// the lowest-common-denominator representation accepted by every OpenAI-
+// compatible gateway. Non-text blocks (thinking, tool calls) are surfaced
+// through their own fields, so they are skipped here.
+func ContentToText(list ContentList) string {
+	var b strings.Builder
+	for _, c := range list {
+		if tc, ok := c.(TextContent); ok {
+			b.WriteString(tc.Text)
+		}
+	}
+	return b.String()
+}
+
+// LastAssistantOf returns a pointer to the last AssistantMessage in msgs, or nil.
+func LastAssistantOf(msgs []AgentMessage) *AssistantMessage {
+	for i := len(msgs) - 1; i >= 0; i-- {
+		if a, ok := msgs[i].(AssistantMessage); ok {
+			return &a
+		}
+	}
+	return nil
+}
+
+// EmitFunc emits a loop-level AgentEvent honoring cancellation.
+type EmitFunc func(ctx context.Context, ev AgentEvent) error
+
+// PrepareArgumentsFunc optionally rewrites a tool's raw arguments before schema
+// validation (e.g. injecting defaults). An error aborts the call with an error
+// result. Optional (nil = identity).
+type PrepareArgumentsFunc func(ctx context.Context, toolName string, args json.RawMessage) (json.RawMessage, error)
+
+// BeforeToolCallDecision is the optional result of the beforeToolCall hook. When
+// Block is true the tool is not executed and an error result is produced;
+// Content/Details override the default block message when set. When Block is
+// false and UpdatedInput is non-empty, it replaces the tool's raw arguments
+// before execution (PreToolUse rewrite, FR-8); the replacement is re-validated
+// against the tool schema.
+type BeforeToolCallDecision struct {
+	Block        bool
+	Content      *ContentList
+	Details      *any
+	UpdatedInput json.RawMessage
+}
+
+// BeforeToolCallFunc runs after validation and may block the call (permission /
+// sandbox checks, FR-4/FR-26). Returning nil allows the call. Optional.
+type BeforeToolCallFunc func(ctx context.Context, call AgentToolCall) *BeforeToolCallDecision
+
+// AfterToolCallFunc runs after execution and may override the result
+// field-by-field via AfterToolCallResult (FR-5, no deep merge). Optional.
+type AfterToolCallFunc func(ctx context.Context, call AgentToolCall, result AgentToolResult, isError bool) *AfterToolCallResult