// Package provider holds the plumbing every app module shares: loading its local
// values file, channel id normalization and aliasing, and the boilerplate half of
// app.App. Module packages embed Base and add their own navigation and catalog.
package provider

import (
	"fmt"
	"os"
	"path/filepath"
	"sort"
	"strings"

	"drmdecryption/capture"
	"drmdecryption/modcfg"
	"drmdecryption/phonecap"
	"drmdecryption/repo"
)

// Common is the part of a module.yaml that every module has. Modules embed it in
// their own config struct with `yaml:",inline"`.
type Common struct {
	Package    string            `yaml:"package"`
	LicenseURL string            `yaml:"license_url"`
	ProxyBin   string            `yaml:"proxy_bin"`
	CAHash     string            `yaml:"ca_hash"`
	Aliases    map[string]string `yaml:"aliases"`
	Score      capture.ScoreCfg  `yaml:"score"`
}

// Base implements the boilerplate half of app.App.
type Base struct {
	name     string
	common   Common
	labels   map[string]string // canonical channel id -> label
	cacheDir string
	cfg      modcfg.Result
}

// New builds a Base. labels maps canonical channel ids to display labels.
func New(name string, common Common, labels map[string]string, cfg modcfg.Result) *Base {
	root := repo.Root()
	cacheDir := filepath.Join(root, ".cache", "ui-"+name)
	_ = os.MkdirAll(cacheDir, 0o755)
	return &Base{name: name, common: common, labels: labels, cacheDir: cacheDir, cfg: cfg}
}

func (b *Base) Name() string       { return b.name }
func (b *Base) Package() string    { return b.common.Package }
func (b *Base) LicenseURL() string { return b.common.LicenseURL }
func (b *Base) CacheDir() string   { return b.cacheDir }

// ConfigPath / ConfigLoaded report where this module's values came from.
func (b *Base) ConfigPath() string { return b.cfg.Path }
func (b *Base) ConfigLoaded() bool { return b.cfg.Loaded }

// ProxyBin resolves the on-device MITM binary, relative paths against repo root.
func (b *Base) ProxyBin() string {
	if b.common.ProxyBin != "" {
		return modcfg.Resolve(b.common.ProxyBin)
	}
	root := repo.Root()
	for _, p := range []string{
		filepath.Join(root, "bin", "proxy-android-arm64"),
		filepath.Join(root, "apps", "proxy", "proxy-android-arm64"),
	} {
		if st, err := os.Stat(p); err == nil && !st.IsDir() {
			return p
		}
	}
	return filepath.Join(root, "bin", "proxy-android-arm64")
}

func (b *Base) CAHash() string {
	if b.common.CAHash == "" {
		return phonecap.DefaultCAHash
	}
	return b.common.CAHash
}

// Score is this module's manifest-URL scoring, merged onto the neutral baseline.
func (b *Base) Score() capture.ScoreCfg {
	return capture.DefaultScoreCfg().Merge(b.common.Score)
}

// Hints returns device-layout hints with this module's scoring applied.
func (b *Base) Hints(require ...string) capture.Hints {
	h := capture.DefaultHints()
	h.Require = require
	h.Score = b.Score()
	return h
}

// NormalizeID folds a channel id to its comparison form.
func NormalizeID(id string) string {
	id = strings.ToLower(strings.TrimSpace(id))
	for _, ch := range []string{"-", "_", " "} {
		id = strings.ReplaceAll(id, ch, "")
	}
	return id
}

// Resolve maps any spelling or alias of a channel to its canonical id.
func (b *Base) Resolve(id string) (string, error) {
	want := NormalizeID(id)
	for canon := range b.labels {
		if NormalizeID(canon) == want {
			return canon, nil
		}
	}
	for alias, canon := range b.common.Aliases {
		if NormalizeID(alias) == want {
			if _, ok := b.labels[canon]; ok {
				return canon, nil
			}
		}
	}
	known := make([]string, 0, len(b.labels))
	for k := range b.labels {
		known = append(known, k)
	}
	return "", fmt.Errorf("unknown channel %q for %s (known: %s) — add it to %s",
		id, b.name, strings.Join(known, "|"), b.cfg.Path)
}

func (b *Base) HasChannel(id string) bool {
	_, err := b.Resolve(id)
	return err == nil
}

// Label returns a channel's display label, falling back to its id.
func (b *Base) Label(canonID string) string {
	if l := b.labels[canonID]; l != "" {
		return l
	}
	return canonID
}

// ChannelIDs lists canonical channel ids, sorted so listings and API responses
// are stable (map iteration order is not).
func (b *Base) ChannelIDs() []string {
	out := make([]string, 0, len(b.labels))
	for k := range b.labels {
		out = append(out, k)
	}
	sort.Strings(out)
	return out
}