package tui

import (
	"sort"

	"github.com/MDietermann/ArduinoArchSetup/internal/config"
	"github.com/MDietermann/ArduinoArchSetup/internal/module"
)

// Theme is a named colorscheme presented in the wizard. Each entry carries
// per-tool theme names; Plan 3b uses NvChadTheme, later plans add more.
type Theme struct {
	ID          string
	Name        string
	NvChadTheme string
}

// BuiltinThemes is the fixed list the wizard shows. Keep in sync with the
// themes shipped by Plan 3's theme module.
var BuiltinThemes = []Theme{
	{ID: "gruvbox", Name: "Gruvbox Dark", NvChadTheme: "gruvbox"},
	{ID: "catppuccin", Name: "Catppuccin Mocha", NvChadTheme: "catppuccin"},
	{ID: "tokyonight", Name: "Tokyo Night", NvChadTheme: "tokyonight"},
	{ID: "nord", Name: "Nord", NvChadTheme: "nord"},
	{ID: "dracula", Name: "Dracula", NvChadTheme: "dracula"},
}

// ThemeByID returns the Theme with the given ID. The bool is false when no
// match is found; callers decide whether to fall back or error.
func ThemeByID(themes []Theme, id string) (Theme, bool) {
	for _, t := range themes {
		if t.ID == id {
			return t, true
		}
	}
	return Theme{}, false
}

// ModuleChoice is one row in the module selector.
type ModuleChoice struct {
	ID          string
	Name        string
	Description string
	Selected    bool
}

// WizardState is the payload the wizard fills in and the dashboard reads.
type WizardState struct {
	ThemeID     string
	Modules     []ModuleChoice
	Parallelism int  // advanced; reserved for a future concurrent engine
	HaltOnError bool // advanced
	Confirmed   bool // true once the user hits Confirm on the last screen
}

// NewWizardState builds an initial state from the running config and the
// registered modules. Pre-ticks all modules except those disabled in the
// overlay, defaults the theme to the first built-in theme.
func NewWizardState(cfg config.Config, reg *module.Registry) WizardState {
	disabled := map[string]bool{}
	for _, id := range cfg.DisabledModules {
		disabled[id] = true
	}
	mods := reg.All()
	choices := make([]ModuleChoice, 0, len(mods))
	for _, m := range mods {
		meta := m.Meta()
		choices = append(choices, ModuleChoice{
			ID:          meta.ID,
			Name:        meta.Name,
			Description: meta.Description,
			Selected:    !disabled[meta.ID],
		})
	}
	sort.Slice(choices, func(i, j int) bool { return choices[i].ID < choices[j].ID })

	theme := BuiltinThemes[0].ID
	if override, ok := cfg.ThemeOverrides["__active"]; ok && override != "" {
		theme = override
	}

	return WizardState{
		ThemeID:     theme,
		Modules:     choices,
		Parallelism: 1,
	}
}

// SelectedIDs returns only the checked module IDs.
func (s WizardState) SelectedIDs() []string {
	out := make([]string, 0, len(s.Modules))
	for _, m := range s.Modules {
		if m.Selected {
			out = append(out, m.ID)
		}
	}
	return out
}