package manifest

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

	"github.com/BurntSushi/toml"

	"forge.lclr.dev/AI/mcp-framework/update"
)

const DefaultFile = "mcp.toml"
const EmbeddedSource = "embedded:mcp.toml"

type File struct {
	BinaryName  string      `toml:"binary_name"`
	DocsURL     string      `toml:"docs_url"`
	Update      Update      `toml:"update"`
	Environment Environment `toml:"environment"`
	SecretStore SecretStore `toml:"secret_store"`
	Profiles    Profiles    `toml:"profiles"`
	Bootstrap   Bootstrap   `toml:"bootstrap"`
	Config      Config      `toml:"config"`
}

type Update struct {
	SourceName                 string   `toml:"source_name"`
	Driver                     string   `toml:"driver"`
	Repository                 string   `toml:"repository"`
	BaseURL                    string   `toml:"base_url"`
	LatestReleaseURL           string   `toml:"latest_release_url"`
	AssetNameTemplate          string   `toml:"asset_name_template"`
	ChecksumAssetName          string   `toml:"checksum_asset_name"`
	ChecksumRequired           bool     `toml:"checksum_required"`
	SignatureAssetName         string   `toml:"signature_asset_name"`
	SignatureRequired          bool     `toml:"signature_required"`
	SignaturePublicKey         string   `toml:"signature_public_key"`
	SignaturePublicKeyEnvNames []string `toml:"signature_public_key_env_names"`
	TokenHeader                string   `toml:"token_header"`
	TokenPrefix                string   `toml:"token_prefix"`
	TokenEnvNames              []string `toml:"token_env_names"`
}

type Environment struct {
	Known []string `toml:"known"`
}

type SecretStore struct {
	BackendPolicy  string `toml:"backend_policy"`
	BitwardenCache *bool  `toml:"bitwarden_cache"`
}

type Profiles struct {
	Default string   `toml:"default"`
	Known   []string `toml:"known"`
}

type Bootstrap struct {
	Description string `toml:"description"`
}

type Config struct {
	Fields []ConfigField `toml:"fields"`
}

type ConfigField struct {
	Name              string   `toml:"name"`
	Flag              string   `toml:"flag"`
	Env               string   `toml:"env"`
	ConfigKey         string   `toml:"config_key"`
	SecretKeyTemplate string   `toml:"secret_key_template"`
	Type              string   `toml:"type"`
	Label             string   `toml:"label"`
	Default           string   `toml:"default"`
	Required          bool     `toml:"required"`
	Sources           []string `toml:"sources"`
}

type BootstrapMetadata struct {
	BinaryName     string
	Description    string
	DocsURL        string
	DefaultProfile string
	Profiles       []string
}

type ScaffoldMetadata struct {
	BinaryName                string
	DocsURL                   string
	KnownEnvironmentVariables []string
	SecretStorePolicy         string
	DefaultProfile            string
	Profiles                  []string
}

func Find(startDir string) (string, error) {
	dir := strings.TrimSpace(startDir)
	if dir == "" {
		wd, err := os.Getwd()
		if err != nil {
			return "", fmt.Errorf("resolve working directory: %w", err)
		}
		dir = wd
	}

	absDir, err := filepath.Abs(dir)
	if err != nil {
		return "", fmt.Errorf("resolve manifest search path %q: %w", dir, err)
	}

	for {
		path := filepath.Join(absDir, DefaultFile)
		info, err := os.Stat(path)
		switch {
		case err == nil:
			if info.IsDir() {
				return "", fmt.Errorf("manifest path %q is a directory", path)
			}
			return path, nil
		case !errors.Is(err, os.ErrNotExist):
			return "", fmt.Errorf("stat manifest %q: %w", path, err)
		}

		parent := filepath.Dir(absDir)
		if parent == absDir {
			return "", fmt.Errorf("find manifest %q from %q: %w", DefaultFile, dir, os.ErrNotExist)
		}
		absDir = parent
	}
}

func Load(path string) (File, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return File{}, fmt.Errorf("read manifest %s: %w", path, err)
	}

	return parse(data, path)
}

func LoadEmbedded(content string) (File, string, error) {
	trimmed := strings.TrimSpace(content)
	if trimmed == "" {
		return File{}, "", os.ErrNotExist
	}

	file, err := parse([]byte(trimmed), EmbeddedSource)
	if err != nil {
		return File{}, "", err
	}

	return file, EmbeddedSource, nil
}

func LoadDefaultOrEmbedded(startDir, embeddedContent string) (File, string, error) {
	file, path, err := LoadDefault(startDir)
	if err == nil {
		return file, path, nil
	}
	if !errors.Is(err, os.ErrNotExist) {
		return File{}, "", err
	}

	return LoadEmbedded(embeddedContent)
}

func parse(data []byte, source string) (File, error) {
	var file File
	if err := toml.Unmarshal(data, &file); err != nil {
		return File{}, fmt.Errorf("parse manifest %s: %w", source, err)
	}

	file.normalize()
	return file, nil
}

func LoadDefault(startDir string) (File, string, error) {
	path, err := Find(startDir)
	if err != nil {
		return File{}, "", err
	}

	file, err := Load(path)
	if err != nil {
		return File{}, "", err
	}

	return file, path, nil
}

func (f *File) normalize() {
	f.BinaryName = strings.TrimSpace(f.BinaryName)
	f.DocsURL = strings.TrimSpace(f.DocsURL)
	f.Update.normalize()
	f.Environment.normalize()
	f.SecretStore.normalize()
	f.Profiles.normalize()
	f.Bootstrap.normalize()
	f.Config.normalize()
}

func (u *Update) normalize() {
	u.SourceName = strings.TrimSpace(u.SourceName)
	u.Driver = strings.ToLower(strings.TrimSpace(u.Driver))
	u.Repository = strings.Trim(strings.TrimSpace(u.Repository), "/")
	u.BaseURL = strings.TrimRight(strings.TrimSpace(u.BaseURL), "/")
	u.LatestReleaseURL = strings.TrimSpace(u.LatestReleaseURL)
	u.AssetNameTemplate = strings.TrimSpace(u.AssetNameTemplate)
	u.ChecksumAssetName = strings.TrimSpace(u.ChecksumAssetName)
	u.SignatureAssetName = strings.TrimSpace(u.SignatureAssetName)
	u.SignaturePublicKey = strings.TrimSpace(u.SignaturePublicKey)
	u.SignaturePublicKeyEnvNames = normalizeStringList(u.SignaturePublicKeyEnvNames)
	u.TokenHeader = strings.TrimSpace(u.TokenHeader)
	u.TokenPrefix = strings.TrimSpace(u.TokenPrefix)
	u.TokenEnvNames = normalizeStringList(u.TokenEnvNames)
}

func (e *Environment) normalize() {
	e.Known = normalizeStringList(e.Known)
}

func (s *SecretStore) normalize() {
	s.BackendPolicy = strings.TrimSpace(s.BackendPolicy)
}

func (p *Profiles) normalize() {
	p.Default = strings.TrimSpace(p.Default)
	p.Known = normalizeStringList(p.Known)
}

func (b *Bootstrap) normalize() {
	b.Description = strings.TrimSpace(b.Description)
}

func (c *Config) normalize() {
	for i := range c.Fields {
		c.Fields[i].normalize()
	}
}

func (f *ConfigField) normalize() {
	f.Name = strings.TrimSpace(f.Name)
	f.Flag = strings.TrimSpace(f.Flag)
	f.Env = strings.TrimSpace(f.Env)
	f.ConfigKey = strings.TrimSpace(f.ConfigKey)
	f.SecretKeyTemplate = strings.TrimSpace(f.SecretKeyTemplate)
	f.Type = strings.ToLower(strings.TrimSpace(f.Type))
	f.Label = strings.TrimSpace(f.Label)
	f.Default = strings.TrimSpace(f.Default)
	f.Sources = normalizeStringList(f.Sources)
}

func (u Update) ReleaseSource() update.ReleaseSource {
	u.normalize()

	return update.ReleaseSource{
		Name:                       u.SourceName,
		Driver:                     u.Driver,
		Repository:                 u.Repository,
		BaseURL:                    u.BaseURL,
		LatestReleaseURL:           u.LatestReleaseURL,
		AssetNameTemplate:          u.AssetNameTemplate,
		ChecksumAssetName:          u.ChecksumAssetName,
		ChecksumRequired:           u.ChecksumRequired,
		SignatureAssetName:         u.SignatureAssetName,
		SignatureRequired:          u.SignatureRequired,
		SignaturePublicKey:         u.SignaturePublicKey,
		SignaturePublicKeyEnvNames: append([]string(nil), u.SignaturePublicKeyEnvNames...),
		TokenHeader:                u.TokenHeader,
		TokenPrefix:                u.TokenPrefix,
		TokenEnvNames:              append([]string(nil), u.TokenEnvNames...),
	}
}

func (f File) BootstrapInfo() BootstrapMetadata {
	f.normalize()

	return BootstrapMetadata{
		BinaryName:     f.BinaryName,
		Description:    f.Bootstrap.Description,
		DocsURL:        f.DocsURL,
		DefaultProfile: f.Profiles.Default,
		Profiles:       append([]string(nil), f.Profiles.Known...),
	}
}

func (f File) ScaffoldInfo() ScaffoldMetadata {
	f.normalize()

	return ScaffoldMetadata{
		BinaryName:                f.BinaryName,
		DocsURL:                   f.DocsURL,
		KnownEnvironmentVariables: append([]string(nil), f.Environment.Known...),
		SecretStorePolicy:         f.SecretStore.BackendPolicy,
		DefaultProfile:            f.Profiles.Default,
		Profiles:                  append([]string(nil), f.Profiles.Known...),
	}
}

func normalizeStringList(values []string) []string {
	normalized := values[:0]
	for _, value := range values {
		if trimmed := strings.TrimSpace(value); trimmed != "" {
			normalized = append(normalized, trimmed)
		}
	}
	return normalized
}