package agent

import (
	"strings"
	"testing"

	"reasonix/internal/evidence"
	"reasonix/internal/instruction"
	"reasonix/internal/provider"
)

func readinessLedger(receipts ...evidence.Receipt) *evidence.Ledger {
	l := evidence.NewLedger()
	for _, r := range receipts {
		l.Record(r)
	}
	return l
}

func TestFinalReadinessFailureBranches(t *testing.T) {
	check := instruction.VerifyCheck{Command: "go test ./...", SourcePath: "AGENTS.md", Line: 3}
	writer := evidence.Receipt{ToolName: "write_file", Success: true, Write: true, Paths: []string{"a.go"}}
	readOnly := evidence.Receipt{ToolName: "read_file", Success: true, Read: true, Paths: []string{"a.go"}}
	checkAfter := evidence.Receipt{ToolName: "bash", Success: true, Command: "go test ./..."}
	todo := evidence.Receipt{ToolName: "todo_write", Success: true, Todos: []evidence.TodoItem{{Content: "edit", Status: "in_progress"}}}
	completeAfter := evidence.Receipt{ToolName: "complete_step", Success: true, Step: "edit"}
	doneTodo := evidence.Receipt{ToolName: "todo_write", Success: true, Todos: []evidence.TodoItem{{Content: "edit", Status: "completed"}}}

	cases := []struct {
		name        string
		checks      []instruction.VerifyCheck
		evidence    *evidence.Ledger
		closedLoop  bool
		wantEmpty   bool
		wantContain string
	}{
		{"nil evidence never gates", []instruction.VerifyCheck{check}, nil, false, true, ""},
		{"no writer never gates", []instruction.VerifyCheck{check}, readinessLedger(checkAfter), false, true, ""},
		{"todo-only turn may end with incomplete list", nil, readinessLedger(todo), false, true, ""},
		{"read-only context plus todo may end with incomplete list", nil, readinessLedger(readOnly, todo), false, true, ""},
		{"completed todo without writer satisfies", nil, readinessLedger(doneTodo), false, true, ""},
		{"writer without checks or todo never gates", nil, readinessLedger(writer), false, true, ""},
		{"missing project check after writer is reported", []instruction.VerifyCheck{check}, readinessLedger(checkAfter, writer), false, false, "go test ./..."},
		{"project check run after writer satisfies", []instruction.VerifyCheck{check}, readinessLedger(writer, checkAfter), false, true, ""},
		{"open turn with unfinished todos is not a delivery contradiction", nil, readinessLedger(writer, todo), false, true, ""},
		{"closed-loop todo writer without complete_step is reported", nil, readinessLedger(writer, todo), true, false, "incomplete items"},
		{"closed-loop complete_step without final todo update is reported", nil, readinessLedger(writer, todo, completeAfter), true, false, "latest successful todo_write"},
		{"todo writer with complete_step and completed todo satisfies", nil, readinessLedger(writer, todo, completeAfter, doneTodo), false, true, ""},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			a := &Agent{task: taskRuntime{ledger: tc.evidence}, projectChecks: tc.checks, turn: turnRuntime{deliveryScopeActive: tc.closedLoop}}
			got := a.ReadinessResult()
			if tc.wantEmpty {
				if !got.Ready {
					t.Fatalf("ReadinessResult() = %+v, want ready (no gate)", got)
				}
				return
			}
			if got.Ready {
				t.Fatalf("ReadinessResult() = ready, want a failure mentioning %q", tc.wantContain)
			}
			if !strings.Contains(got.Reason, tc.wantContain) {
				t.Fatalf("ReadinessResult().Reason = %q, want it to mention %q", got.Reason, tc.wantContain)
			}
			if len(got.Missing) == 0 {
				t.Fatalf("ReadinessResult().Missing empty for %q", tc.wantContain)
			}
		})
	}
}

func TestFinalReadinessAllowsIncompleteTodosInPlanMode(t *testing.T) {
	todo := evidence.Receipt{ToolName: "todo_write", Success: true, Todos: []evidence.TodoItem{{Content: "draft implementation plan", Status: "pending"}}}
	a := &Agent{task: taskRuntime{ledger: readinessLedger(todo)}}
	a.SetPlanMode(true)

	if got := a.ReadinessResult(); !got.Ready {
		t.Fatalf("ReadinessResult() = %+v, want ready in plan mode", got)
	}
	if got := a.finalReadinessCheckFor(); got.applies {
		t.Fatalf("finalReadinessCheckFor() applies in plan mode: %+v", got)
	}
}

func TestFinalReadinessCheckAuditsIncompleteTodos(t *testing.T) {
	todo := evidence.Receipt{ToolName: "todo_write", Success: true, Todos: []evidence.TodoItem{{Content: "edit", Status: "in_progress"}}}
	writer := evidence.Receipt{ToolName: "write_file", Success: true, Write: true, Paths: []string{"a.go"}}
	open := &Agent{task: taskRuntime{ledger: readinessLedger(writer, todo)}}
	if got := open.finalReadinessCheckFor(); got.applies {
		t.Fatalf("open-turn finalReadinessCheckFor() applies = true, want false: %+v", got)
	}

	closed := &Agent{task: taskRuntime{ledger: readinessLedger(writer, todo)}, turn: turnRuntime{deliveryScopeActive: true}}
	got := closed.finalReadinessCheckFor()
	if !got.applies {
		t.Fatalf("closed-loop finalReadinessCheckFor() applies = false, want true")
	}
	if got.incompleteTodos != 1 {
		t.Fatalf("incompleteTodos = %d, want 1", got.incompleteTodos)
	}
	if !strings.Contains(got.reason, "latest successful todo_write") {
		t.Fatalf("reason = %q, want incomplete todo message", got.reason)
	}
	audit := got.audit(evidence.ReadinessBlocked, false)
	if audit.IncompleteTodos != 1 {
		t.Fatalf("audit.IncompleteTodos = %d, want 1", audit.IncompleteTodos)
	}
}

func TestFinalReadinessAllowsFinalAfterLoopGuardedToolBlocker(t *testing.T) {
	todo := evidence.Receipt{ToolName: "todo_write", Success: true, Todos: []evidence.TodoItem{{Content: "edit", Status: "in_progress"}}}
	writer := evidence.Receipt{ToolName: "write_file", Success: true, Write: true, Paths: []string{"a.go"}}
	ledger := readinessLedger(writer, todo)
	a := &Agent{task: taskRuntime{ledger: ledger}, turn: turnRuntime{deliveryScopeActive: true}}
	a.armLoopGuardPass(ledger.Len())

	got := a.finalReadinessCheckFor()
	if !got.applies {
		t.Fatalf("finalReadinessCheckFor() applies = false, want true audit after loop guard")
	}
	if got.reason != "" {
		t.Fatalf("finalReadinessCheckFor() reason = %q, want loop guard to allow final blocker report", got.reason)
	}
}

// TestFinalReadinessLoopGuardPassSurvivesBookkeeping proves the exact actions
// the loop guard recommends — ask, todo_write, complete_step — do not revoke
// the pass: the model must be able to record the blocker and then report it.
func TestFinalReadinessLoopGuardPassSurvivesBookkeeping(t *testing.T) {
	todo := evidence.Receipt{ToolName: "todo_write", Success: true, Todos: []evidence.TodoItem{{Content: "edit", Status: "in_progress"}}}
	writer := evidence.Receipt{ToolName: "write_file", Success: true, Write: true, Paths: []string{"a.go"}}
	ledger := readinessLedger(writer, todo)
	a := &Agent{task: taskRuntime{ledger: ledger}, turn: turnRuntime{deliveryScopeActive: true}}
	a.armLoopGuardPass(ledger.Len())

	ledger.Record(evidence.Receipt{ToolName: "ask", Success: true})
	ledger.Record(evidence.Receipt{ToolName: "todo_write", Success: true, Todos: []evidence.TodoItem{{Content: "edit", Status: "in_progress"}}})
	ledger.Record(evidence.Receipt{ToolName: "complete_step", Success: true, Step: "edit"})

	if got := a.finalReadinessCheckFor(); got.reason != "" {
		t.Fatalf("finalReadinessCheckFor() reason = %q, want bookkeeping after the guard to keep the pass", got.reason)
	}
}

// TestFinalReadinessLoopGuardPassRevokedByRealProgress proves a successful
// write or command receipt after the guard revokes the pass: receipts are
// obtainable again, so readiness resumes enforcing them.
func TestFinalReadinessLoopGuardPassRevokedByRealProgress(t *testing.T) {
	todo := evidence.Receipt{ToolName: "todo_write", Success: true, Todos: []evidence.TodoItem{{Content: "edit", Status: "in_progress"}}}
	writer := evidence.Receipt{ToolName: "write_file", Success: true, Write: true, Paths: []string{"a.go"}}
	ledger := readinessLedger(writer, todo)
	a := &Agent{task: taskRuntime{ledger: ledger}, turn: turnRuntime{deliveryScopeActive: true}}
	a.armLoopGuardPass(ledger.Len())

	ledger.Record(evidence.Receipt{ToolName: "bash", Success: true, Command: "go test ./..."})

	if got := a.finalReadinessCheckFor(); got.reason == "" {
		t.Fatal("finalReadinessCheckFor() reason empty, want real progress after the guard to revoke the pass")
	}
}

// TestFinalReadinessIgnoresLoopGuardQuotedInToolOutput proves the pass is host
// state, not message text: a tool result that merely quotes "[loop guard]"
// (a grep over this repo, a pasted transcript) must not unlock readiness.
func TestFinalReadinessIgnoresLoopGuardQuotedInToolOutput(t *testing.T) {
	todo := evidence.Receipt{ToolName: "todo_write", Success: true, Todos: []evidence.TodoItem{{Content: "edit", Status: "in_progress"}}}
	writer := evidence.Receipt{ToolName: "write_file", Success: true, Write: true, Paths: []string{"a.go"}}
	sess := NewSession("")
	sess.Add(provider.Message{Role: provider.RoleUser, Content: "edit"})
	sess.Add(provider.Message{Role: provider.RoleAssistant, ToolCalls: []provider.ToolCall{{ID: "b1", Name: "bash"}}})
	sess.Add(provider.Message{Role: provider.RoleTool, ToolCallID: "b1", Name: "bash", Content: "agent.go:2082: \"[loop guard] %s has now %s %d times\""})
	a := &Agent{task: taskRuntime{ledger: readinessLedger(writer, todo)}, sess: sessionRuntime{conversation: sess}, turn: turnRuntime{deliveryScopeActive: true}}

	if got := a.finalReadinessCheckFor(); got.reason == "" {
		t.Fatal("finalReadinessCheckFor() reason empty, want quoted loop-guard text to be ignored")
	}
}