package app

import (
	"errors"
	"log/slog"
	"os"
	"testing"

	"github.com/stretchr/testify/assert"
)

func TestNewLifecycle(t *testing.T) {
	assert := assert.New(t)

	// Create a blank Lifecycle instance
	lc := NewLifecycle()
	assert.NotNil(lc, "expected Lifecycle instance to be created")
	assert.Equal(slog.Default(), lc.Logger(), "expected default logger to be available")

	// Create a blank Lifecycle instance with a custom logger
	handler := slog.NewTextHandler(os.Stderr, nil)
	logger := slog.New(handler)
	lc = NewLifecycle().WithOpts(LifecycleOpts{
		Logger: logger,
	})

	assert.NotNil(lc)
	assert.Equal(logger, lc.Logger(), "expected logger to match")
	assert.Len(lc.modules, 0, "expected modules to be empty")
	assert.Len(lc.setupTracker, 0, "expected setup tracker to be empty")
	assert.Len(lc.teardownTracker, 0, "expected teardown tracker to be empty")

	// Test with modules
	mod1 := NewModule("module1", ModuleOpts{})
	mod2 := NewModule("module2", ModuleOpts{})

	lcWithModules := NewLifecycle(mod1, mod2)
	assert.NotNil(lcWithModules, "expected Lifecycle with modules to be created")
	assert.Contains(lcWithModules.modules, mod1, "expected module1 to be included")
	assert.Contains(lcWithModules.modules, mod2, "expected module2 to be included")
	assert.Len(lcWithModules.modules, 2, "expected two modules to be present")

	// Test for duplicate module names
	assert.PanicsWithValue("duplicate module: [module1]", func() {
		NewLifecycle(mod1, mod1)
	}, "expected panic on duplicate module names")
}

func TestLifecycle_WithOpts(t *testing.T) {
	assert := assert.New(t)

	lc := NewLifecycle()
	opts := LifecycleOpts{
		DisableAutoload: true,
	}

	lc.WithOpts(opts)
	assert.Equal(opts, lc.opts, "expected Lifecycle to have the provided options")
}

func TestLifecycle_WithLogger(t *testing.T) {
	assert := assert.New(t)

	lc := NewLifecycle()
	logger := slog.New(slog.NewTextHandler(os.Stderr, nil))
	lc.WithLogger(logger)
	assert.Equal(logger, lc.Logger(), "expected Lifecycle to have the provided logger")
}

func TestLifecycle_Logger(t *testing.T) {
	assert := assert.New(t)

	lc := NewLifecycle()
	assert.Equal(slog.Default(), lc.Logger(), "expected Logger to return a logger")

	// Test that custom logger is used
	logger := slog.New(slog.NewTextHandler(os.Stderr, nil))
	lc.opts.Logger = logger
	assert.Equal(logger, lc.Logger())
}

func TestLifecycle_Setup(t *testing.T) {
	cases := []struct {
		name        string
		modules     []*Module
		expectedErr string
	}{
		{
			name:    "empty lifecycle",
			modules: nil,
		},
		{
			name: "single module with setup",
			modules: []*Module{
				NewModule("module1", ModuleOpts{
					Setup: func(m *Module) error { return nil },
				}),
			},
		},
		{
			name: "multiple modules",
			modules: []*Module{
				NewModule("module1", ModuleOpts{}),
				NewModule("module2", ModuleOpts{
					Setup: func(m *Module) error { return nil },
				}),
			},
		},
		{
			name: "module with setup error",
			modules: []*Module{
				NewModule("module1", ModuleOpts{
					Setup: func(m *Module) error { return errors.New("setup failed") },
				}),
			},
			expectedErr: "setup failed",
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			assert := assert.New(t)

			lc := NewLifecycle(tc.modules...)

			err := lc.Setup()

			if tc.expectedErr == "" {
				assert.NoError(err, "expected Setup to succeed")
				for _, mod := range tc.modules {
					if mod.setup != nil {
						_, ok := lc.setupTracker[mod.name]
						assert.True(ok, "expected module to be marked as set up")
					}
				}
			} else {
				assert.Error(err, "expected Setup to fail")
				assert.Contains(err.Error(), tc.expectedErr, "expected error message to match")
			}
		})
	}
}

func TestLifecycle_Teardown(t *testing.T) {
	cases := []struct {
		name        string
		modules     []*Module
		expectedErr []string
	}{
		{
			name:    "empty lifecycle",
			modules: nil,
		},
		{
			name: "single module with teardown",
			modules: []*Module{
				NewModule("module1", ModuleOpts{
					Teardown: func(m *Module) error { return nil },
				}),
			},
		},
		{
			name: "multiple modules",
			modules: []*Module{
				NewModule("module1", ModuleOpts{}),
				NewModule("module2", ModuleOpts{
					Teardown: func(m *Module) error { return nil },
				}),
			},
		},
		{
			name: "module with teardown error",
			modules: []*Module{
				NewModule("module1", ModuleOpts{
					Teardown: func(m *Module) error { return errors.New("teardown failed") },
				}),
			},
			expectedErr: []string{"teardown failed"},
		},
		{
			name: "multiple modules with teardown errors",
			modules: []*Module{
				NewModule("module1", ModuleOpts{
					Teardown: func(m *Module) error { return errors.New("module1 teardown failed") },
				}),
				NewModule("module2", ModuleOpts{
					Teardown: func(m *Module) error { return errors.New("module2 teardown failed") },
				}),
			},
			expectedErr: []string{"module1 teardown failed", "module2 teardown failed"},
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			assert := assert.New(t)

			lc := NewLifecycle(tc.modules...)

			// Fake setup for all modules
			for _, mod := range tc.modules {
				mod.loaded = true             // Mark as loaded
				lc.setupTracker[mod.name] = 0 // Mark as set up
			}

			err := lc.Teardown()

			if len(tc.expectedErr) == 0 {
				assert.NoError(err, "expected Teardown to succeed")
				for _, mod := range tc.modules {
					if mod.teardown != nil {
						_, ok := lc.teardownTracker[mod.name]
						assert.Truef(ok, "expected module %s to be marked as torn down", mod)
						assert.Falsef(mod.loaded, "expected module %s to be unloaded after teardown", mod)
					}
				}
			} else {
				assert.Error(err, "expected Teardown to fail")
				for _, expected := range tc.expectedErr {
					assert.Contains(err.Error(), expected, "expected error message to match")
				}
			}
		})
	}
}

func TestLifecycle_Require(t *testing.T) {
	lc := NewLifecycle()
	mod := NewModule("module1", ModuleOpts{
		Setup: func(m *Module) error { return nil },
	})
	err := lc.Require(mod)
	assert.NoError(t, err, "expected Require to succeed")
	assert.Contains(t, lc.setupTracker, mod.name, "expected module to be marked as set up")
	assert.Nil(t, mod.logger, "expected module logger to be nil")
	assert.Equal(t, lc.Logger(), mod.Logger(), "expected module logger to match lifecycle logger")
}

func TestLifecycle_RequireUnique(t *testing.T) {
	assert := assert.New(t)
	lc := NewLifecycle()

	mod := NewModule("module1", ModuleOpts{})
	err := lc.RequireUnique(mod)
	assert.NoError(err, "expected RequireL to succeed")
	assert.Nil(mod.logger, "expected module logger to be nil")

	// Requiring the same module again should fail
	err = lc.RequireUnique(mod)
	assert.Error(err, "expected RequireUnique to fail on duplicate module")
}

func TestLifecycle_RequireL(t *testing.T) {
	// Create a logger for the test cases
	logger := slog.New(slog.NewTextHandler(os.Stderr, nil))

	cases := []struct {
		name            string
		modules         []*Module
		existingModules []*Module
		expectedErr     string
	}{
		{
			name:        "no modules",
			expectedErr: "no modules to require",
		},
		{
			name:        "nil module",
			modules:     []*Module{nil},
			expectedErr: "is nil",
		},
		{
			name: "basic module",
			modules: []*Module{
				NewModule("testModule", ModuleOpts{
					Setup: func(m *Module) error {
						if m.name != "testModule" {
							return errors.New("module name mismatch")
						}
						return nil
					},
				}),
			},
		},
		{
			name: "several modules",
			modules: []*Module{
				NewModule("module1", ModuleOpts{
					Setup: func(m *Module) error { return nil },
				}),
				NewModule("module2", ModuleOpts{
					Setup: func(m *Module) error { return nil },
				}),
			},
		},
		{
			name: "module with setup error",
			modules: []*Module{
				NewModule("errorModule", ModuleOpts{
					Setup: func(m *Module) error { return errors.New("setup failed") },
				}),
			},
			expectedErr: "setup failed",
		},
		{
			name: "module with dependency",
			modules: []*Module{
				NewModule("dependentModule", ModuleOpts{
					Setup:   func(m *Module) error { return nil },
					Depends: []string{"dependencyModule"},
				}),
			},
			existingModules: []*Module{
				NewModule("dependencyModule", ModuleOpts{
					Setup: func(m *Module) error { return nil },
				}),
			},
		},
		{
			name: "duplicate module names",
			modules: []*Module{
				NewModule("duplicateModule", ModuleOpts{}),
				NewModule("duplicateModule", ModuleOpts{}),
			},
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			assert := assert.New(t)

			lc := NewLifecycle(tc.existingModules...)

			err := lc.RequireL(logger, tc.modules...)

			if tc.expectedErr == "" {
				assert.NoError(err, "expected RequireL to succeed")
				for i, mod := range tc.modules {
					if mod != nil {
						_, ok := lc.setupTracker[mod.name]
						assert.Truef(ok, "expected module %d %s to be marked as set up", i, mod)
						assert.Truef(mod.loaded, "expected module %d %s to be loaded", i, mod)
						assert.Equalf(logger, mod.logger, "expected module %d %s logger to match", i, mod)
					}
				}
			} else {
				assert.Error(err, "expected RequireL to fail")
				assert.Contains(err.Error(), tc.expectedErr, "expected error message to match")
			}
		})
	}
}

func TestLifecycle_RequireUniqueL(t *testing.T) {
	// Create a logger for the test cases
	logger := slog.New(slog.NewTextHandler(os.Stderr, nil))

	cases := []struct {
		name            string
		modules         []*Module
		existingModules []string
		expectedErr     string
	}{
		{
			name: "no existing modules",
			modules: []*Module{
				NewModule("module1", ModuleOpts{}),
			},
		},
		{
			name: "module already set up",
			modules: []*Module{
				NewModule("module1", ModuleOpts{}),
				NewModule("module2", ModuleOpts{}),
			},
			existingModules: []string{"module1"},
			expectedErr:     "module [module1] is already set up, cannot require it again",
		},
		{
			name:        "nil module",
			modules:     []*Module{nil},
			expectedErr: "is nil",
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			assert := assert.New(t)
			lc := NewLifecycle()

			// Fake existing modules
			for _, modName := range tc.existingModules {
				lc.setupTracker[modName] = 0 // Mark as set up
			}

			err := lc.RequireUniqueL(logger, tc.modules...)
			if tc.expectedErr == "" {
				assert.NoError(err, "expected RequireUniqueL to succeed")
			} else {
				assert.Error(err, "expected RequireUniqueL to fail")
				assert.Contains(err.Error(), tc.expectedErr, "expected error message to match")
			}
		})
	}
}

func TestLifecycle_setupSingle(t *testing.T) {
	// Create a logger for the test cases
	logger := slog.New(slog.NewTextHandler(os.Stderr, nil))

	cases := []struct {
		name         string
		lc           *Lifecycle
		targetModule *Module
		modules      []*Module
		expectedErr  string
		logger       *slog.Logger
	}{
		{
			name:         "nil module",
			targetModule: nil,
			expectedErr:  "module is nil",
		},
		{
			name: "basic module setup",
			targetModule: NewModule("testModule", ModuleOpts{
				Setup: func(m *Module) error {
					if m.name != "testModule" {
						return errors.New("module name mismatch")
					}
					return nil
				},
			}),
		},
		{
			name: "module with dependencies",
			targetModule: NewModule("dependentModule", ModuleOpts{
				Setup:   func(m *Module) error { return nil },
				Depends: []string{"dependencyModule"},
			}),
			modules: []*Module{
				NewModule("dependencyModule", ModuleOpts{
					Setup: func(m *Module) error { return nil },
				}),
			},
		},
		{
			name: "module with missing dependency",
			targetModule: NewModule("dependentModule", ModuleOpts{
				Setup:   func(m *Module) error { return nil },
				Depends: []string{"missingDependency"},
			}),
			expectedErr: "error getting dependency",
		},
		{
			name: "module setup error",
			targetModule: NewModule("errorModule", ModuleOpts{
				Setup: func(m *Module) error { return errors.New("setup failed") },
			}),
			expectedErr: "setup failed",
		},
		{
			name: "module dependency setup error",
			targetModule: NewModule("moduleWithoutError", ModuleOpts{
				Setup:   func(m *Module) error { return nil },
				Depends: []string{"errorModule"},
			}),
			modules: []*Module{
				NewModule("errorModule", ModuleOpts{
					Setup: func(m *Module) error { return errors.New("dependency setup failed") },
				}),
			},
			expectedErr: "dependency setup failed",
		},
		{
			name: "dependency without autoload",
			lc: NewLifecycle().WithOpts(LifecycleOpts{
				DisableAutoload: true,
			}),
			targetModule: NewModule("dependentModule", ModuleOpts{
				Setup:   func(m *Module) error { return nil },
				Depends: []string{"dependencyModule"},
			}),
			expectedErr: "not satisfied",
		},
		{
			name:         "module without setup function",
			targetModule: NewModule("noSetupModule", ModuleOpts{}),
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			assert := assert.New(t)

			l := tc.logger
			if l == nil {
				l = logger
			}

			lc := tc.lc
			if lc == nil {
				lc = NewLifecycle(tc.modules...)
			}

			err := lc.setupSingle(l, tc.targetModule)

			if tc.expectedErr == "" {
				assert.NoError(err, "expected no error from setupSingle")
			} else {
				assert.Contains(err.Error(), tc.expectedErr, "expected error message to match")
			}

			if tc.targetModule != nil {
				assert.Equal(l, tc.targetModule.logger, "expected module logger to match")
			}
		})
	}
}

func TestLifecycle_teardownSingle(t *testing.T) {
	cases := []struct {
		name         string
		targetModule *Module
		modules      []string
		expectedErr  string
	}{
		{
			name:        "nil module",
			expectedErr: "module is nil",
		},
		{
			name: "basic module teardown",
			targetModule: NewModule("testModule", ModuleOpts{
				Teardown: func(m *Module) error {
					if m.name != "testModule" {
						return errors.New("module name mismatch")
					}
					return nil
				},
			}),
			modules: []string{"testModule"},
		},
		{
			name: "module not set up",
			targetModule: NewModule("notSetUpModule", ModuleOpts{
				Teardown: func(m *Module) error { return nil },
			}),
			expectedErr: "not set up, cannot tear down",
		},
		{
			name:         "module without teardown function",
			targetModule: NewModule("noTeardownModule", ModuleOpts{}),
			modules:      []string{"noTeardownModule"},
		},
		{
			name: "module with teardown error",
			targetModule: NewModule("errorModule", ModuleOpts{
				Teardown: func(m *Module) error { return errors.New("teardown failed") },
			}),
			modules:     []string{"errorModule"},
			expectedErr: "error tearing down",
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			assert := assert.New(t)

			lc := NewLifecycle()

			// Fake setup for all modules
			var setupCount int
			for _, mod := range tc.modules {
				lc.setupTracker[mod] = setupCount
				setupCount++
			}

			err := lc.teardownSingle(tc.targetModule)

			if tc.expectedErr == "" {
				assert.NoError(err, "expected no error from teardownSingle")
			} else {
				assert.Contains(err.Error(), tc.expectedErr, "expected error message to match")
			}
		})
	}
}

func Test_mapToString(t *testing.T) {
	cases := []struct {
		name     string
		input    map[string]int
		expected string
	}{
		{
			name:     "empty map",
			input:    map[string]int{},
			expected: "[]",
		},
		{
			name:     "single entry",
			input:    map[string]int{"key1": 0},
			expected: "['key1']",
		},
		{
			name:     "multiple entries",
			input:    map[string]int{"key1": 0, "key2": 3, "key3": 2},
			expected: "['key1' 'key3' 'key2']",
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			assert := assert.New(t)
			result := mapToString(tc.input)
			assert.Equal(tc.expected, result, "expected mapToString to return correct string representation")
		})
	}
}