package tui

import (
	"testing"

	"superwork-tui/internal/issue"
)

// ── isBlocked truth table ─────────────────────────────────────────────────────

func TestIsBlocked_NoPrerequisite(t *testing.T) {
	it := issue.Issue{Number: 1, Column: issue.ColumnTodo, Prerequisite: 0}
	if isBlocked(it, []issue.Issue{it}) {
		t.Error("isBlocked = true, want false when Prerequisite == 0")
	}
}

func TestIsBlocked_PrereqInDone(t *testing.T) {
	prereq := issue.Issue{Number: 2, Column: issue.ColumnDone}
	it := issue.Issue{Number: 1, Column: issue.ColumnTodo, Prerequisite: 2}
	if isBlocked(it, []issue.Issue{it, prereq}) {
		t.Error("isBlocked = true, want false when prerequisite is in ColumnDone")
	}
}

func TestIsBlocked_PrereqNotInDone(t *testing.T) {
	prereq := issue.Issue{Number: 2, Column: issue.ColumnTodo}
	it := issue.Issue{Number: 1, Column: issue.ColumnTodo, Prerequisite: 2}
	if !isBlocked(it, []issue.Issue{it, prereq}) {
		t.Error("isBlocked = false, want true when prerequisite is in ColumnTodo")
	}
}

func TestIsBlocked_PrereqInProgress(t *testing.T) {
	prereq := issue.Issue{Number: 2, Column: issue.ColumnInProgress}
	it := issue.Issue{Number: 1, Column: issue.ColumnTodo, Prerequisite: 2}
	if !isBlocked(it, []issue.Issue{it, prereq}) {
		t.Error("isBlocked = false, want true when prerequisite is in ColumnInProgress")
	}
}

func TestIsBlocked_PrereqNotFound(t *testing.T) {
	it := issue.Issue{Number: 1, Column: issue.ColumnTodo, Prerequisite: 99}
	if !isBlocked(it, []issue.Issue{it}) {
		t.Error("isBlocked = false, want true when prerequisite is not found")
	}
}

// ── todoDepTree grouping ──────────────────────────────────────────────────────

func TestTodoDepTree_NoDeps(t *testing.T) {
	todos := []issue.Issue{
		{Number: 1, Column: issue.ColumnTodo},
		{Number: 2, Column: issue.ColumnTodo},
		{Number: 3, Column: issue.ColumnTodo},
	}
	entries := todoDepTree(todos)
	if len(entries) != 3 {
		t.Fatalf("len = %d, want 3", len(entries))
	}
	for i, e := range entries {
		if e.indent {
			t.Errorf("entries[%d].indent = true, want false (no deps)", i)
		}
		if e.iss.Number != todos[i].Number {
			t.Errorf("entries[%d].iss.Number = %d, want %d", i, e.iss.Number, todos[i].Number)
		}
	}
}

func TestTodoDepTree_BlockedChildAfterParent(t *testing.T) {
	// #2 depends on #1; both in todo. #3 is independent.
	todos := []issue.Issue{
		{Number: 1, Column: issue.ColumnTodo, Prerequisite: 0},
		{Number: 2, Column: issue.ColumnTodo, Prerequisite: 1},
		{Number: 3, Column: issue.ColumnTodo, Prerequisite: 0},
	}
	entries := todoDepTree(todos)
	if len(entries) != 3 {
		t.Fatalf("len = %d, want 3", len(entries))
	}
	// Expected order: #1 (not indented), #2 (indented under #1), #3 (not indented)
	if entries[0].iss.Number != 1 || entries[0].indent {
		t.Errorf("entries[0] = {%d, indent=%v}, want {1, false}", entries[0].iss.Number, entries[0].indent)
	}
	if entries[1].iss.Number != 2 || !entries[1].indent {
		t.Errorf("entries[1] = {%d, indent=%v}, want {2, true}", entries[1].iss.Number, entries[1].indent)
	}
	if entries[2].iss.Number != 3 || entries[2].indent {
		t.Errorf("entries[2] = {%d, indent=%v}, want {3, false}", entries[2].iss.Number, entries[2].indent)
	}
}

func TestTodoDepTree_ParentNotInTodo(t *testing.T) {
	// #1 depends on #99 which is not in the todo list → #1 appears at top level.
	todos := []issue.Issue{
		{Number: 1, Column: issue.ColumnTodo, Prerequisite: 99},
		{Number: 2, Column: issue.ColumnTodo, Prerequisite: 0},
	}
	entries := todoDepTree(todos)
	if len(entries) != 2 {
		t.Fatalf("len = %d, want 2", len(entries))
	}
	if entries[0].iss.Number != 1 || entries[0].indent {
		t.Errorf("entries[0] = {%d, indent=%v}, want {1, false}", entries[0].iss.Number, entries[0].indent)
	}
	if entries[1].iss.Number != 2 || entries[1].indent {
		t.Errorf("entries[1] = {%d, indent=%v}, want {2, false}", entries[1].iss.Number, entries[1].indent)
	}
}

func TestTodoDepTree_AllEmitted(t *testing.T) {
	// Ensure no duplicates and all issues appear exactly once.
	todos := []issue.Issue{
		{Number: 10, Column: issue.ColumnTodo, Prerequisite: 0},
		{Number: 11, Column: issue.ColumnTodo, Prerequisite: 10},
		{Number: 12, Column: issue.ColumnTodo, Prerequisite: 10},
	}
	entries := todoDepTree(todos)
	if len(entries) != 3 {
		t.Fatalf("len = %d, want 3", len(entries))
	}
	seen := make(map[int]int)
	for _, e := range entries {
		seen[e.iss.Number]++
	}
	for _, iss := range todos {
		if seen[iss.Number] != 1 {
			t.Errorf("issue #%d appeared %d times, want 1", iss.Number, seen[iss.Number])
		}
	}
}