package app

import (
	"context"
	"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 TestLifecycleToFromContext(t *testing.T) {
	assert := assert.New(t)

	// Create a Lifecycle instance
	lc := NewLifecycle()

	// Add the Lifecycle to the context
	ctx := LifecycleToContext(context.Background(), lc)

	// Retrieve the Lifecycle from the context
	retrievedLC := LifecycleFromContext(ctx)

	assert.NotNil(retrievedLC, "expected Lifecycle to be retrieved from context")
	assert.Equal(lc, retrievedLC, "expected retrieved Lifecycle to match original")

	// Test with nil Lifecycle
	nilCtx := LifecycleToContext(context.Background(), nil)
	retrievedNilLC := LifecycleFromContext(nilCtx)
	assert.Nil(retrievedNilLC, "expected nil Lifecycle to return nil from context")
}

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")

	assert.PanicsWithValue("logger cannot be nil", func() {
		lc.WithLogger(nil)
	}, "expected panic when setting nil 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())

	// Test with nil Lifecycle
	assert.PanicsWithValue("lifecycle is nil, cannot get logger", func() {
		var nilLC *Lifecycle
		nilLC.Logger()
	}, "expected panic when calling Logger on nil Lifecycle")
}

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) {
	assert := assert.New(t)

	lc := NewLifecycle()

	// Test that duplicate modules are allowed
	mod1 := NewModule("module1", ModuleOpts{})
	mod2 := NewModule("module1", ModuleOpts{})
	err := lc.Require(mod1, mod2)
	assert.NoError(err, "expected Require to succeed with duplicate modules")
	assert.Len(lc.modules, 1, "expected only one instance of the module to be added")
	assert.Equal(lc.Logger(), mod1.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, mod)
	assert.Error(err, "expected RequireUnique to fail on duplicate module")
}

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

	// Create a logger for the test cases
	logger := slog.New(slog.NewTextHandler(os.Stderr, nil))

	lc := NewLifecycle()

	// Test that duplicate modules are allowed with RequireL
	mod1 := NewModule("module1", ModuleOpts{})
	mod2 := NewModule("module1", ModuleOpts{})
	err := lc.RequireL(logger, mod1, mod2)
	assert.NoError(err, "expected RequireL to succeed with duplicate modules")
	assert.Len(lc.modules, 1, "expected only one instance of the module to be added")
	assert.Equal(logger, mod1.Logger(), "expected module logger to match provided logger")

	// Test with nil logger
	err = lc.RequireL(nil, mod1)
	assert.Error(err, "expected RequireL to fail with nil logger")
}

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

	// Create a logger for the test cases
	logger := slog.New(slog.NewTextHandler(os.Stderr, nil))

	lc := NewLifecycle()

	// Test that duplicate modules are not allowed with RequireUniqueL
	mod1 := NewModule("module1", ModuleOpts{})
	mod2 := NewModule("module1", ModuleOpts{})
	err := lc.RequireUniqueL(logger, mod1, mod2)
	assert.Error(err, "expected RequireUniqueL to fail on duplicate module")
	assert.Contains(err.Error(), "cannot require again", "expected error message to match")

	// Test with nil logger
	err = lc.RequireUniqueL(nil, mod1)
	assert.Error(err, "expected RequireUniqueL to fail with nil logger")
}

func TestLifecycle_require(t *testing.T) {
	cases := []struct {
		name        string
		logger      *slog.Logger
		unique      bool
		modules     []*Module
		expectedErr string
		length      int
	}{
		{
			name:        "no modules",
			expectedErr: "no modules to require",
		},
		{
			name: "nil module",
			modules: []*Module{
				NewModule("", ModuleOpts{}),
				nil,
			},
			expectedErr: "module 1 is nil",
		},
		{
			name: "basic modules",
			modules: []*Module{
				NewModule("module1", ModuleOpts{}),
				NewModule("module2", ModuleOpts{}),
			},
		},
		{
			name: "module with setup error",
			modules: []*Module{
				NewModule("errorModule", ModuleOpts{
					Setup: func(m *Module) error { return errors.New("setup failed") },
				}),
			},
			expectedErr: "error setting up required module",
		},
		{
			name: "duplicate module names",
			modules: []*Module{
				NewModule("duplicateModule", ModuleOpts{}),
				NewModule("duplicateModule", ModuleOpts{}),
			},
			length: 1, // Expect only one instance to be added
		},
		{
			name:   "duplicate module names with unique",
			unique: true,
			modules: []*Module{
				NewModule("duplicateModule", ModuleOpts{}),
				NewModule("duplicateModule", ModuleOpts{}),
			},
			expectedErr: "cannot require again",
		},
	}

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

			lc := NewLifecycle()
			err := lc.require(tc.logger, tc.unique, tc.modules...)

			if tc.expectedErr == "" {
				assert.NoError(err, "expected require to succeed")

				expectedLength := tc.length
				if expectedLength == 0 {
					expectedLength = len(tc.modules)
				}
				assert.Equal(expectedLength, len(lc.modules), "expected all modules to be added to lifecycle")

				for _, mod := range tc.modules {
					if mod != nil {
						_, ok := lc.setupTracker[mod.name]
						assert.Truef(ok, "expected module %s to be marked as set up", mod)
						assert.Truef(mod.loaded, "expected module %s to be loaded", mod)
						assert.Equalf(lc, mod.lifecycle, "expected module %s lifecycle to match", mod)

						if tc.logger != nil {
							assert.Equalf(tc.logger, mod.Logger(), "expected module %s logger to match", mod)
						} else {
							assert.Equalf(lc.Logger(), mod.Logger(), "expected module %s logger to match lifecycle logger", mod)
						}
					}
				}
			} else {
				assert.Error(err, "expected require 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")
		})
	}
}