// SPDX-License-Identifier: EUPL-1.2

package api

import (
	"context"
	"iter"
	"maps"
	"slices"

	core "dappco.re/go/core"
)

// Supported SDK target languages.
var supportedLanguages = map[string]string{
	"go":               "go",
	"typescript-fetch": "typescript-fetch",
	"typescript-axios": "typescript-axios",
	"python":           "python",
	"java":             "java",
	"csharp":           "csharp-netcore",
	"ruby":             "ruby",
	"swift":            "swift5",
	"kotlin":           "kotlin",
	"rust":             "rust",
	"php":              "php",
}

// SDKGenerator wraps openapi-generator-cli for SDK generation.
type SDKGenerator struct {
	SpecPath    string
	OutputDir   string
	PackageName string
}

// Generate creates an SDK for the given language using openapi-generator-cli.
// Routes through c.Process() — requires go-process registered.
//
//	r := gen.Generate(ctx, c, "go")
func (g *SDKGenerator) Generate(ctx context.Context, c *core.Core, language string) core.Result {
	generator, ok := supportedLanguages[language]
	if !ok {
		return core.Result{Value: core.E("SDKGenerator.Generate", core.Sprintf("unsupported language %q", language), nil), OK: false}
	}

	fs := c.Fs()
	if !fs.Exists(g.SpecPath) {
		return core.Result{Value: core.E("SDKGenerator.Generate", core.Concat("spec file not found: ", g.SpecPath), nil), OK: false}
	}

	outputDir := core.JoinPath(g.OutputDir, language)
	fs.EnsureDir(outputDir)

	args := g.buildArgs(generator, outputDir)
	return c.Process().Run(ctx, "openapi-generator-cli", args...)
}

// buildArgs constructs the openapi-generator-cli command arguments.
func (g *SDKGenerator) buildArgs(generator, outputDir string) []string {
	args := []string{
		"generate",
		"-i", g.SpecPath,
		"-g", generator,
		"-o", outputDir,
	}
	if g.PackageName != "" {
		args = append(args, "--additional-properties", core.Concat("packageName=", g.PackageName))
	}
	return args
}

// Available checks if openapi-generator-cli is installed.
// Uses App.Find which searches PATH without importing os/exec.
//
//	r := gen.Available()
func (g *SDKGenerator) Available() bool {
	r := core.App{}.Find("openapi-generator-cli", "OpenAPI Generator")
	return r.OK
}

// SupportedLanguages returns the list of supported SDK target languages.
func SupportedLanguages() []string {
	return slices.Sorted(maps.Keys(supportedLanguages))
}

// SupportedLanguagesIter returns an iterator over supported SDK target languages.
func SupportedLanguagesIter() iter.Seq[string] {
	return slices.Values(SupportedLanguages())
}